Re: [M100] M100 Information

[Jeffrey Birt]

The missing horizontal stripes could be ab LCD driver issue, LCD glass
issue, zebra strip issue or issue with corrosion on the LCD PCB. 

 

Jeff Birt

 

From: M100  On Behalf Of Russell Pitman
Sent: Friday, December 31, 2021 7:28 PM
To: m...@bitchin100.com
Subject: Re: [M100] M100 Information

 

OK, 

 

Progress has been made!  It now seems to boot.  I still feel that a new VR1
is needed as this one is VERY sensitive.

 

Next issue is that of missing lines on the screen...

 

Looks like the screen is in 2 halves and the top line is playing up on
both...

 

Getting excited now, new toy lol

 

Thanks

Russ

 

 

 

Sent from Mail   for Windows

 

From: Brian K. White  
Sent: 01 January 2022 01:18
To: m...@bitchin100.com  
Subject: Re: [M100] M100 Information

 

Thanks much, and wow.

If you look at page 71, pages 70 and 71 are the same, but 70 is a low 
res scan and 71 is a high res scan. It shows both the main and option 
roms right next to each other and sure enough shows that their pinouts 
are different.

I have uploaded a cropped and de-duped copy to archive.org, so for 
everyone else, you can see page 70 here:
https://archive.org/details/kyotronic-kc-85-service-manual/
(download the pdf, the web viewer is super blurry)
https://archive.org/download/kyotronic-kc-85-service-manual/Kyotronic_KC-85_
Service_Manual.pdf


I have the user guide and basic manuals, and I just noticed that the 
user guide the section at the end with all the interface pinouts, 
doesn't even mention the option rom socket at all, even though it does 
include the system bus socket. Though does not include the ram sockets 
either. Even the service manual doesn't mention the option rom socket in 
the same section where all the other interfaces are described. Strange.

I guess this means that if you ever wanted to create an option rom for 
KC-85, you'd actually have to use a Teeprom or REX to do it!

This is super strange. Maybe the M100 pinout was not invented custom for 
the M100 after all? Like maybe Sharp already had a mask rom model with 
this pinout that Kyocera & Tandy just selected from Sharp's existing 
offerings? Or Kyocera created the custom pinout just for the option rom 
for some reason, and Tandy just kept it and even went further to apply 
it to the main rom, again "for some reason"?

-- 
bkw

On 12/31/21 4:59 PM, Stephen Adolph wrote:
> Brian,
> I will send you a link.
> schematic is a bit blurry.
> ALE on pin 23.  yep same as M100.
> 
> image.png
> 
> I still have the original with me, maybe I can get some better diagrams 
> scanned.
> 
> Steve
> 
> 
> On Fri, Dec 31, 2021 at 4:51 PM Brian K. White mailto:b.kenyo...@gmail.com%20%0b> 
> > wrote:
> 
> On 12/31/21 11:16 AM, Stephen Adolph wrote:
>  > Yep.  Some M100s were built with that PCB, as was the KC-85. 
> Makes sense.
>  > cheers
>  > Steve
> 
> Could you send me the docs you have for the kc-85? A few months ago I
> asked if anyone had downloaded the service manual from the now-dead
> link
> in Don Fox's member directory on club100.
> 
> http://club100.org/memfiles/index.php?directory=Don%20Fox
> 
> 
> At that time you said that you thought you had it and would look.
> 
> I can't believe it's really the same pcb, because if nothing else, I
> can't believe the kc-85 would have the m100 pinout for the option rom,
> and even the late model 100's with a standard pinout for the main rom
> still have the 100 pinout for the option rom.
> 
> kc-85 also has no bcr port or modem, but it does have the
> footprints, so
> possibly the related parts could be populated.
> 
> -- 
> bkw
> 


-- 
bkw

 

Re: [M100] M100 Information

[Jeffrey Birt]

That is interesting, I did not know there was a 3rd version of the M100 PCB. 
Let us know when you are able to upload the manual.

 

Jeff

 

From: M100  On Behalf Of Stephen Adolph
Sent: Friday, December 31, 2021 10:02 AM
To: m...@bitchin100.com
Subject: Re: [M100] M100 Information

 

Russell,

I think you have the same PCB assembly that is used in the KC-85.

 

As such, the KC-85 service manual may be of assistance.

 

I don't see it at club100.org  ; I have a copy here that is 
17MB.  Not sure if it is posted elsewhere.  Anyone know if it is online 
anywhere?

 

We should really get it posted if not online already.

Steve

 

 

On Thu, Dec 30, 2021 at 10:59 PM Russell Pitman mailto:bagpus...@hotmail.co.uk> > wrote:

Hi all

 

I have recently received my first M100 but unfortunately I am unable to get any 
response from it.

 

I have been looking at the circuit diagrams and manuals for it but none seem to 
match the motherboard 

that is inside this model.  Cap and resistor numbers are different.

 

Finally I have noticed that the contrast potentiometer (VR1) is no longer 
working and am wondering if this is

why no display is seen?   Does anyone know where I can source one of these?

 

Many thanks


Russ

 

Sent from Mail   for Windows

 

Re: [M100] M100 Information

[Jeffrey Birt]

In the power supply section there should be some labled test point "GND",
"Vee", "Vcc". The 'Vee' will be -5V for the LCD (and RS232) and the "Vcc"
+5V for everything else. You can also check from ground to the highest
numbered pin on any of the '40Cxx' chips for 5V.

 

Jeff Birt

 

From: M100  On Behalf Of Russell Pitman
Sent: Friday, December 31, 2021 8:52 AM
To: m...@bitchin100.com
Subject: Re: [M100] M100 Information

 

I am not sure that the voltages are coming through either as I need to know
the correct components to check,

With a correct circuit diagram.  I have continuity checked the switch SW3
and that is good.  6v is seen at the battery terminals.

 

I have noticed that Brad does a VR1 kit which might be worth sourcing, if
still available.

 

Thanks


Russ

 

 

Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986>  for Windows

 

From: Jeffrey Birt <mailto:bir...@soigeneris.com> 
Sent: 31 December 2021 13:13
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] M100 Information

 

>> I have been looking at the circuit diagrams and manuals for it but none
seem to match the motherboard 

that is inside this model.  Cap and resistor numbers are different.

 

That would be a very odd PCB. Kyocera even carried the same component
designations through to the Olivetti M-10. The M100 and T102 are different,
are you referencing the correct schematic?

There are two versions of the M100 PCB but the changes are minor. There are
a few component differences in the reset circuit and the RS-232 output. The
later model also uses a standard EPROM pin-out for the ROM. 

Have you checked the power supply voltages? Always start with PCR: Power,
Clock, Reset. Checking these three things first will go a long way to
finding the problem.

 

Jeff Birt

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Russell Pitman
Sent: Thursday, December 30, 2021 10:00 PM
To: m100@lists.bitchin100.com <mailto:m100@lists.bitchin100.com> 
Subject: [M100] M100 Information

 

Hi all

 

I have recently received my first M100 but unfortunately I am unable to get
any response from it.

 

I have been looking at the circuit diagrams and manuals for it but none seem
to match the motherboard 

that is inside this model.  Cap and resistor numbers are different.

 

Finally I have noticed that the contrast potentiometer (VR1) is no longer
working and am wondering if this is

why no display is seen?   Does anyone know where I can source one of these?

 

Many thanks


Russ

 

Sent from Mail <https://go.microsoft.com/fwlink/?LinkId=550986>  for Windows

 

 

Re: [M100] M100 Information

[Jeffrey Birt]

>> I have been looking at the circuit diagrams and manuals for it but none
seem to match the motherboard 

that is inside this model.  Cap and resistor numbers are different.

 

That would be a very odd PCB. Kyocera even carried the same component
designations through to the Olivetti M-10. The M100 and T102 are different,
are you referencing the correct schematic?

There are two versions of the M100 PCB but the changes are minor. There are
a few component differences in the reset circuit and the RS-232 output. The
later model also uses a standard EPROM pin-out for the ROM. 

Have you checked the power supply voltages? Always start with PCR: Power,
Clock, Reset. Checking these three things first will go a long way to
finding the problem.

 

Jeff Birt

 

From: M100  On Behalf Of Russell Pitman
Sent: Thursday, December 30, 2021 10:00 PM
To: m100@lists.bitchin100.com
Subject: [M100] M100 Information

 

Hi all

 

I have recently received my first M100 but unfortunately I am unable to get
any response from it.

 

I have been looking at the circuit diagrams and manuals for it but none seem
to match the motherboard 

that is inside this model.  Cap and resistor numbers are different.

 

Finally I have noticed that the contrast potentiometer (VR1) is no longer
working and am wondering if this is

why no display is seen?   Does anyone know where I can source one of these?

 

Many thanks


Russ

 

Sent from Mail   for Windows

 

Re: [M100] Tandy 200 lcd

[Jeffrey Birt]

Have you measured the -5V supply to see what voltage it actually is? A low -5V 
(closer to 0V) will make for a dim display.

Jeff Birt

-Original Message-
From: M100  On Behalf Of Scott Lawrence
Sent: Friday, December 24, 2021 6:50 PM
To: Model 100 Discussion 
Subject: [M100] Tandy 200 lcd

The lcd on my 200 has horrible contrast. I’d use the thing more but I just 
can’t read the screen.  Have any of you done any mods/repairs for this?

Would the “bivert mod” common for gameboy DMGs work? (Electronically invert the 
screen, and replace the polarizer with a modern one rotated 90)

Are there maybe power supply repairs that would help? 

Thoughts?

Sent from your iPhone.

Re: [M100] New zebra strips for M100 display — any interest?

[Jeffrey Birt]

Jamie,

 

Just wanted to check and see if you were successful in getting some new zebra 
strips made.

 

Jeff Birt

 

From: M100  On Behalf Of Jamie Nichol
Sent: Tuesday, July 6, 2021 6:34 PM
To: m...@bitchin100.com
Subject: [M100] New zebra strips for M100 display — any interest?

 

Hey All,

I do consumer product R as my day job.  I’ve admired the M100 as a brilliant 
product for the past decade or so, and just picked up a really sad example that 
I’m trying to resuscitate.

A couple of weeks ago I had a some fine-pitch prototype zebra strips made up to 
fit the M100 LCD (see pic).  The first prototypes are about 0.3mm too tall.  
I’ll likely have another set of prototypes run with an adjusted height.

I have two questions:

Is there enough interest here on the list to justify an order of 1000 pieces or 
so?  (Likely price is a few dollars each strip — more to come on price.)

Do any of you have dead LCDs that you would be wiling to sacrifice to the 
testing gods?  I would like to see ten or so LCDs improved by an upgrade to the 
new strips before placing a bigger order.

—Jamie

 

 

[M100] Fluke 9010A owners?

[Jeffrey Birt]

A bit off topic but still vintage computer related...

 

Are there any TPDD Backpack owners who are also Fluke 9010A owners? We have
an experimental firmware option that will provide support for the 9010A.
This was created by request to be able to save/load test scripts to/from the
Fluke.

 

It needs some sort of bootloader/menu written for the 9010A, not owning one
ourselves makes this part difficult. I was hoping to find others who might
be interested in Fluke 9010A support.

 

Thanks,

Jeff Birt

Re: [M100] Tandy 102 Help

[Jeffrey Birt]

It may take a while to charge the memory battery. On the T102 the position of 
the battery compartment allows any leakage to fall directly on the PCB. The 
memory backup battery leakage tends to cause much more damage on the T102 as 
well.

Jeff Birt


-Original Message-
From: M100  On Behalf Of Howard Pepper
Sent: Thursday, November 11, 2021 7:59 AM
To: Model 100 Discussion 
Subject: [M100] Tandy 102 Help

Well, I finally did it.  I forgot to change out the AA batteries back in May, 
like I was supposed to.  I live in Florida, and it is very humid pretty much 
all year long, even with the air conditioner running. Anyway I opened my 102 
battery compartment this morning and found two of the four batteries were 
heavily corroded.  I removed those batteries and cleaned the battery 
compartment out and put in new batteries, but now the 102 won't come on, all 
that happens is the screen darkens when I turn it on.

Does this mean the internal Ni-Cad ran out of juice?  If I leave it alone for a 
while, will that Ni-Cad recharge from the AA's?

Thanks for any/all help.

Howard

Re: [M100] NiCd Battery

[Jeffrey Birt]

I suggest replacing the battery if you are going to be using the machine or at 
least removing it at this time is you will not be using the machine. When (not 
if) they leak the damage can be catastrophic. They are 30+ years old now and on 
borrowed time.

I have the batteries in stock as does Arcadeshopper.

 

https://www.soigeneris.com/memory-backup-battery-mbat1 (my shop)

 

Jeff Birt

 

From: M100  On Behalf Of Patrick McDougal
Sent: Wednesday, November 10, 2021 8:10 PM
To: m100@lists.bitchin100.com
Subject: [M100] NiCd Battery

 

Hey all,

 

I am new to the group… I just bought a Model 100 on Ebay after a bit of 
nostalgia for my T200 which I used through college in the 80s.

 

Anyway,  it powers up, has a good LCD, the keyboard is a bit sticky but the 
machine was a bit dirty.  I disassembled it for cleaning and saw the NiCd 
memory battery on the board.  Visually it is good shape but I have read that 
they should “always be replaced or removed”.  I checked the voltage and it is 
4.04 volts.

 

I was hoping for some advice regarding my next step.  Replace?  Remove? Leave 
it alone?

 

If replacement is recommended, can anyone suggest a good vendor for the part?

 

Thanks for any guidance,

 

Patrick

Re: [M100] M100 display suddenly less visible

[Jeffrey Birt]

The easiest way to pull these pots is to use a large soldering iron tip and a 
big blob of solder to heat all 3-4 terminals at once. It is easy to pull out 
when all leads are hot at once. They you can use solder braid or a solder 
sucker to clean out the holes.

Most often you can take the knob loose and drip some contact cleaner into the 
pot and rotate it back and forth to revive it. This does not always work but it 
does most of the time.

 

Jeff Birt

 

From: M100  On Behalf Of George Goodman
Sent: Sunday, November 7, 2021 3:57 PM
To: m100@lists.bitchin100.com
Subject: Re: [M100] M100 display suddenly less visible

 

FYI, it appears the pot is dead, dead, dead (well, it isn't potentiating, just 
letting a rather small bit through). That pot is so small and so very well 
soldered to the board that I don't think I can do anything about it. It appears 
that this M100 will become my donor.

 

My second system arrives this week.

 

Thanks for all the help, folks!

 

george g.

 

--- 

Please note that this email is coming from my new account. Change the contact 
information you have for me to send emails to georgeogood...@orgoodman.net 
 

Thanks!

 

 

On Thu, Nov 4, 2021, at 12:19 PM, George Goodman wrote:

Hi all,

 

My M100 display seems to have taken a turn for the dim. See the images in this 
shared folder —> 
https://www.dropbox.com/sh/y1cpftct6dgqy2j/AAAEb3PmIC1b30qh7FV_WX4ea?dl=0 

 

I can’t point to anything that happened. I started an install of TS-DOS from my 
Backpack and, once the Initial Program Load began, stepped away from my desk to 
get a glass of water. When I returned a few minutes later I thought the M100 
had flat out died. I removed the Backpack and tried turning the M111 on and off 
and even did a hard reset. No joy…I thought.

 

I happened to sit down at my desk and catch a more extreme viewing angle of the 
display. That’s when I realized that there was just a display issue. I verified 
that I can start up Basic, make the system beep, open Text, etc. However, I 
haven’t found anything that will get the display back to good viewing from 
overhead.

 

BTW, I did try the contrast dial and that didn’t have any impact. The images in 
that shared folder were taken with the contrast at its highest.

 

Does anyone have suggestions for debugging and fixing this?

 

Thanks,

 

george g.

 

Re: [M100] various M10 main ROMs please!

[Jeffrey Birt]

>> Not sure it is worth the effort to do that much surgery on the M100 ROM.

 

>> For software compatibility, I think it is more important to represent the 
>> ascii codes in the same way as the M100 would use them.  

So, my plan is to just map them as best is possible, and live with it.

 

I agree, folks are wanting to use the M100 ROM in the M10 to gain access to 
M100 software so the graphics characters are less important. 

 

>> 1)  ASCI 35d = the pound character, not the # character

 

Well, ‘#’ was used to denote pounds, as in weight, long before the catchy ‘hash 
tag’ usage. I might guess they were trying to get the British monetary units in 
without using the extended set, but it is odd as what software would make use 
of it?

 

Jeff

 

From: M100  On Behalf Of Stephen Adolph
Sent: Thursday, October 28, 2021 9:11 AM
To: m...@bitchin100.com
Subject: Re: [M100] various M10 main ROMs please!

 

Re: [M100] various M10 main ROMs please!

[Jeffrey Birt]

Good work Steve. This would make it possible then to modify the M100->M10 ROM 
to read the jumpers and choose correct table IF there is enough room in the 
M100-M10 ROM. Or, I guess probably easier to is have 4 ROM versions, one for 
each table and the user would need to burn the correct one for their KB layout.

 

Jeff

 

 

From: M100  On Behalf Of Stephen Adolph
Sent: Thursday, October 28, 2021 8:14 AM
To: m...@bitchin100.com
Subject: Re: [M100] various M10 main ROMs please!

 

Follow up-

What I have learned:

 

There are only 2 versions of the M10

1) M10 - modem (for USA)

2) M10 - no modem (for rest of world)

 

Each of these has uniquely 1 main ROM, and they are both online. (M10 - USA), 
(M10-EU)

There is a somewhat disassembled listing of the M10 - EU rom on the web ath 
F.J. Kraan's M10 site.

The main ROM from VirtualT comes from this site I believe (because it is 
exactly 8 bytes too large!).

 

The M10 - no modem PCB uses hardwired jumpers at SW-1 and SW-2 to determine the 
keyboard mappings.

 

Schematics

M10-Modem:  findable online at various places.

M10-no modem.  The destuff and configuration from "modem" to "no modem" are 
actually not documented but are indicated on the M10-modem schematic.  There is 
a harder to find scan of the M10-no modem schematic, with some hand scribbled 
modification notes for 128kB RAM upgrade, which DOES show the no-modem 
specifics.

 

 

So, that's that.  

 

one copper layout

2 schematics, with 4 hardware configs for each keyboard type

2 main roms, with the EU rom containing all the 4 keyboard mappings

 

 

 

 

 

 

 

On Mon, Oct 25, 2021 at 10:03 PM Stephen Adolph mailto:twospru...@gmail.com> > wrote:

5. QZERTY ITALY 

 

On Mon, Oct 25, 2021 at 9:26 PM Stephen Adolph mailto:twospru...@gmail.com> > wrote:

Hello,

I'm gathering main ROMs for M10.

I think there are 5 different keyboards,

 

1. QWERTY USA (got that rom)

2. QWERTY UK (got that rom)

3. AZERTY  FRANCE (I have a listing for that)

 

need:

4. QWERTZ GERMANY 

5. QWERTY ITALY

 

Could use these ROMs if anyone has them, thanks!

Steve

Re: [M100] Bleaching of yellowed plastic

[Jeffrey Birt]

Happy to hear it worked out for you.

Jeff

-Original Message-
From: M100  On Behalf Of Jamil Alioui
Sent: Saturday, October 23, 2021 9:38 AM
To: m100@lists.bitchin100.com
Subject: Re: [M100] Bleaching of yellowed plastic

Hi,

Thanks to Justin and Jeff for their valuable advice and references.

I did the procedure with the hair bleach gel and indeed, the result is 
wonderful.

Re: [M100] NEC PC-8201 Replacement for 16X 104M Green capacitor

[Jeffrey Birt]

Disconnect the power input to the computer, i.e. external supply plug and/or AA 
batteries. Wait 1 minute. Measure voltage across memory backup battery.

Jeff Birt

-Original Message-
From: M100  On Behalf Of ExPLIT | Pawel 
Radomychelski
Sent: Friday, October 22, 2021 12:40 PM
To: m...@bitchin100.com
Subject: Re: [M100] NEC PC-8201 Replacement for 16X 104M Green capacitor

I measured the CN1 on the powwer supply board.

PIN 6 should be 5V OK
PIN 3 should be -5V OK
PIN 4 should be 5V OK
PIN 5 should be GND OK
PIN 12 should be 5V OK
PIN 16 should be 6V Not OK (-0,1 / -0,2V) PIN 18 should be 9V OK Not OK (6,7V)

I measured with a simple cheap multimeter between GND (PIN 5) and every
PIN)

So, it seems like Power board is bad?




On Fri, 2021-10-22 at 12:47 -0400, Stephen Adolph wrote:
> Pawel,
> Black screen usually indicates a deeper problem than a cap.
> +5V good?
> -5V good?
> activity on the CLK signal at the processor?
> check that data and address are toggling @ the main ROM and RAM 
> sockets?
> pull and reseat ROM and RAM modules?
> 
> just a few suggestions.
> Do you have something like a scope to be able to look at signals?
> 
> 
> 
> On Fri, Oct 22, 2021 at 12:02 PM ExPLIT | Pawel Radomychelski 
>  wrote:
> > Thanks Steve,
> > Tried cliping it out - same issue. Just black screen (screen full of 
> > black pixels)
> > 
> > Tried replace the ROM Chip - same.
> > Will try to replace the cap.
> > 
> > Thanks
> > 
> > 
> > On Fri, 2021-10-22 at 09:32 -0400, Stephen Adolph wrote:
> > > can you just clip it out and carry on?
> > > 
> > > On Fri, Oct 22, 2021 at 9:10 AM ExPLIT | Pawel Radomychelski 
> > >  wrote:
> > > > Hello collegues!
> > > > 
> > > > I bought another "non-working" NEC PC-8201 (Japansese Model).
> > > > Found out that one green capacitor 16X 104M is broken.
> > > > Now i am looking for the modern replacement. Someone know, what 
> > > > modern replacment i can use?
> > > > 
> > > > Thanks
> > > > 
> > > > 
> > 

--
Kind regards /
Mit freundlichen Grüßen

ExPLIT IT Solutions
Pawel Radomychelski

Re: [M100] Recompile multiple BA files

[Jeffrey Birt]

Say you are a new owner of an M100 and you try to load ‘file.ba’ which shows up 
in the menu as ‘file.do’, what will you guess the problem is. You might try it 
again and get the same result and get pretty frustrated.

If I copy ‘file.ba’ to my SD card and then it does not show up as being on the 
card I will again be frustrated as I won’t know why this is happening. 

I have been chatting with the developer about an error message. The concern 
there is that there are a limited number of error messages that TS-DOS 
supports, and the user would need to be able to associate the error to what the 
problem was. We all know how frustrating a seemly meaningless error message is.

 

I do appreciate the idea.

 

Jeff Birt

 

From: M100  On Behalf Of John R. Hogerhuis
Sent: Thursday, October 21, 2021 3:02 PM
To: m...@bitchin100.com
Subject: Re: [M100] Recompile multiple BA files

 

The closest thing to a perfect solution... that just works... is for the disk 
service to present the proper extension instead of the incorrect one. That's 
what Laddiealpha does. It peeks at beginning of the file to see if it's a 
binary file and automatically presents a correct extension to TSDOS. Whether 
the user knows how to load that file is a separate concern. But I figure people 
will simply ask on list.

 

Other ways to go:

 

Do not present the file at all in the directory if a mismatch is detected. The 
user will see it as a mystery but they can read their documentation or ask on 
list and the mystery will be resolved. Another idea would be to rename it in 
some way to be clearly bad like "FILE.><" So it's not just missing. 

 

Present the filename as is. But when at the protocol level the file is opened 
or on the first read then an error is returned based on inspection of the file. 
TSDOS or whatever will report the error and the user may figure it out or they 
will ask on list. I haven't explored this but theoretically it should be 
feasible.

 

Embed a tokenizer in the file server to automatically make the content match 
the extension. This won't always work. And it would have to be laptop model 
aware since 100 vs NEC tokens. 

 

-- John. 

 

Re: [M100] Recompile multiple BA files

[Jeffrey Birt]

You could use DOSBOX or some other virtual machine. They all take time to 
figure out, but it is an option.

 

Jeff Birt

 

From: M100  On Behalf Of AvantGuard Systems
Sent: Thursday, October 21, 2021 4:11 PM
To: m...@bitchin100.com
Subject: Re: [M100] Recompile multiple BA files

 

In response to Mike. 

I got your entoke.exe file, but it on a Win10 computer and it only works on 
32-bit computers. Have a Win95 computer here, so maybe I'll give it a go on it. 
If Win95 isn't 16-bit

Looking forward to Bob's version!

Re: [M100] Recompile multiple BA files

[Jeffrey Birt]

These are all interesting ideas but still require the user to know ahead of 
time that the problem of mismatched extensions exists and how to work around 
it. The LOAD"0:PROG.DO” might be the easiest thing to recommend once someone 
realizes they have this problem, but then that also requires they know a bit 
more about TS-DOS.

 

Thanks for the ideas,

Jeff Birt

 

 

 

First of all there's 

 

Load"COM:98N1E

Or

 

Run"COM:98N1E

 

Even better if you are using TSDOS  I believe you just need to use it in DOS-ON 
mode.

 

LOAD"0:PROG.DO

 

should load a text encoded BASIC program in one step IIRC.

 

-- John.  

 

 

 

Re: [M100] Recompile multiple BA files

[Jeffrey Birt]

It might be possible to have the Backpack  return a TS-DOS error message if you 
try to load a .BA file is really a .DO. The choice of messages is limited 
though. If this error message were shown when you tried to load a .BA file what 
would be your first thought?

 

"Bad File Name"

 

We would mention this in the manual of course but is it more confusing, less 
confusing or the same for newbies?

 

Another option is to add to the existing file check CLI commands so it can 
identify incorrect BA/DO extensions. This would require using the CLI though.

 

The goal is to make it a better user experience. Your thoughts?

Jeff Birt

 

From: Jeffrey Birt  
Sent: Thursday, October 21, 2021 7:58 AM
To: 'm...@bitchin100.com' 
Subject: RE: [M100] Recompile multiple BA files

 

Re: [M100] Bleaching of yellowed plastic

[Jeffrey Birt]

Hi,

While 'Retr0Brite', i.e. using hydrogen peroxide to whiten plastic is a 
bleaching process other types of bleach do not work the same. Bleaching agents, 
hydrogen peroxide, chlorine bleach, etc. do not work exactly the same so can't 
be interchanged for this use case.

If you want to learn all about the process from where the color comes from to 
why the bleaching process works I did a video about that: 
https://youtu.be/YPl356YKcVs . In the video description is a link to a folder 
which has a paper that goes along with the video and other resources.

Someone has already mentioned obtaining hydrogen peroxide in the form of hair 
developer. Indeed, this is usually the least expensive source. You can also use 
sodium percarbonate which comes as a powder (it is hydrogen peroxide and soda 
ash). Mix the sodium percarbonate with hot water to dissolve it. The drawback 
is the soda ash is alkaline and may corrode any bits of metal given enough time.

You can also use 'SunBriting' which is plain old fashioned sun bleaching. 

Lots of details in the video and paper.

Jeff Birt



-Original Message-
From: M100  On Behalf Of Jamil Alioui
Sent: Thursday, October 21, 2021 2:37 AM
To: m...@bitchin100.com
Subject: [M100] Bleaching of yellowed plastic

Hello to all of you,

I have a small practical question, which will be my first on this list. 
I quickly looked in the archives but found nothing about this. I hope to knock 
on the right door.

What is the best method to whiten the yellowed plastic of a Model 100 without 
damaging the screen or sanding (=smoothing) the relief or erasing the 
inscriptions? I found several possibilities on the internet. 
One of them is to rub the material with a baking soda paste. But the one time I 
tried this, the matte plastic turned shiny. I considered dipping the case and 
keyboard keys in household vinegar, but wanted to make sure it wouldn't affect 
anything else. I also imagined bathing the yellowed parts in hydrogen peroxide, 
but this product is very expensive in Switzerland.

Thanks in advance; kind regards,

Jamil Alioui
(Lausanne, Switzerland)

Re: [M100] Recompile multiple BA files

[Jeffrey Birt]

This would not solve the underlying problem(s).

 

A.  New users of the M100 always get bitten in the butt by this BA/DO file 
issue. 
B.  Once you learn it is a problem you still have the manual process of 
making sure the sure the extension of the file is correct. Loading a .DO as a 
.DO into RAM. Opening this .DO into BASIC and saving it as a .BA to tokenize 
it. 
C.  If it is a large program, you may not have enough RAM to hold the .DO 
and .BA versions at once. Someone on the Discord server wrote a program that 
will pull a .DO from the Backpack one line at a time, tokenize it and save it 
to RAM. This is still a manual process.
D.  If you have a number of programs you want to tokenize this manual 
process takes a lot of time.

 

The offline tokenizing programs would make short work of it though IIF one 
knows about the DO/BA issue and knows that these programs exist.

 

Jeff Birt

 

From: M100  On Behalf Of Francois Gurin
Sent: Thursday, October 21, 2021 6:50 AM
To: m...@bitchin100.com
Subject: Re: [M100] Recompile multiple BA files

 

 

On Wed, Oct 20, 2021, 7:20 PM John R. Hogerhuis mailto:jho...@pobox.com> > wrote:

 

For example, what LaddieAlpha does is it looks at the file and determines if it 
is formatted as plain text or tokenized basic, and when, say TS-DOS requests 
the directory it presents the filename with corrected extension on the fly. 
That's one way to handle it.

 

 

Firmware update for the Backpack to do the same? ;)

 

--fg

Re: [M100] Recompile multiple BA files

[Jeffrey Birt]

Renaming the files is not the issue. The issue is that many text files are 
incorrectly named as .BA. As you know if you try to load a text file labeled as 
.BA the M100 will try to tokenize it on the fly, and it is not fast enough to 
keep up.

 

Jeff Birt

 

From: M100  On Behalf Of John R. Hogerhuis
Sent: Wednesday, October 20, 2021 3:23 PM
To: m...@bitchin100.com
Subject: Re: [M100] Recompile multiple BA files

 

Well. Tokenized files do load faster. But aside from that I don't see the 
trouble in just naming files correctly. That's the best fix. You're using a 
Backpack... Laddiealpha autodetects and presents the correct extension itself 
if you mess up. That's the way I solved it. 

 

If you want to automate tokenization you could write a program to connect to 
VirtualT debug socket and use the real tokenizer. 

 

The other way is to use a tokenizer on the PC. I think there's one around.  But 
I'm not sure how accurate it is. 

 

-- John. 

Re: [M100] corroded battery contacts

[Jeffrey Birt]

That might work. I have also tried mixing a little glycerin with the acid to 
make it more viscous. This slows down the reaction but does help keep it in 
place.

 

Jeff

 

From: M100  On Behalf Of Francois Gurin
Sent: Monday, October 18, 2021 7:04 PM
To: m...@bitchin100.com
Subject: Re: [M100] corroded battery contacts

 

Thanks Jeff

 

I'll give botH a try.   Do you think vinegar soaked cottton balls would be 
effective to clean them up in place?  If i open it up I may as well replace 
them!

 

Re: [M100] corroded battery contacts

[Jeffrey Birt]

Soak in a mild acid such as vinegar or citric acid. Afterword rinse the coat 
with WD-40.

It is possible to buy some nice new battery contacts now too. I did a video 
recently about this after a friend gave me a tip about the new contacts being 
available from Aliexpress. 

https://youtu.be/HwqvUbz0vPY

Jeff Birt

 

From: M100  On Behalf Of Francois Gurin
Sent: Monday, October 18, 2021 10:45 AM
To: m...@bitchin100.com
Subject: [M100] corroded battery contacts

 

 

Hi All,

 

This isn't specifically an m100 question, but is one that relates and I'm sure 
people here will have experience with this.  I have an Amstrad NC-200 with 
severely corroded battery terminals.  When it's just battery leakage, I have 
always had good luck with contact cleaner (I use WD-40 brand contact cleaner 
and a toothbrush for cleaning pretty much everything, it's a lot easier for me 
to work with that the various deoxits and other brands) and on extreme cases 
help from a knife or some steel wool.

 

Contact cleaner isn't doing much, and it's very resistant to scraping.  I have 
a feeling this is straight up rust which I (knock on wood) don't have much 
experience with on electronics or a combination of both battery leakage and 
rust.   

 

Short of fully replacing the terminals, any ideas on how to clean up these 
terminals?

 

--fg 

 

 

Re: [M100] pdd.sh

[Jeffrey Birt]

Great work Brian!

Jeff Birt 

-Original Message-
From: M100  On Behalf Of Brian K. White
Sent: Thursday, September 16, 2021 5:44 PM
To: M100 List 
Subject: [M100] pdd.sh

Finally got TPDD2 support working in pdd.sh, including sector access, including 
write, including the metadata parts necessary for a full working disk copy, 
including disks with "special" bits like both tpdd1 and tpdd2 utility disks and 
the Disk Power KC-85 disk.

pdd.sh can now create working, bootable, both TPDD1 and TPDD2 utility disks 
from disk image files. And both of those images are in the same github repo.

TPDD2 normal file access works too of course, you can read/write both banks.

Also includes a send_loader command to install loader.ba files, since, why not? 
Even handier than dlplus since it's just a bash script.

https://github.com/bkw777/pdd.sh

--
bkw

Re: [M100] Disk for PDD2

[Jeffrey Birt]

The disks were imaged using a SuperCard Pro which is a flux level disk imager. 
It is a small board that connects to a PC type floppy drive and controls the 
drive directly. It steps through the entire drive surface making a map of the 
flux transitions so it can image/copy any disk. You could also use a Kyroflux 
or Grease weasel in a similar manner. 

I was able to use the SCP to image 99% of the 5-1/4” C64 disks form my 
childhood. It is a fantastic bit of kit.  
https://www.cbmstuff.com/index.php?route=product/product 
 
_id=52

 

Hopefully Brian will chime in about his new method of making boot disks. I have 
to say that the easiest route though is to get a REX and use TSDOS.

 

Did you get the RS-232 cable with the drive?

 

Jeff

 

From: M100  On Behalf Of Chris Kmiec
Sent: Thursday, September 2, 2021 6:53 PM
To: m...@bitchin100.com
Subject: Re: [M100] Disk for PDD2

 

Jeff, I was under the assumption that those disks were hard to image due to 
their formating, is that not the case?

 

All I have is a USB floppy drive that I have successfully used to make 720K 
disks for Amiga/Atari ST, and a new-to-me TPPD2 drive that I am not sure is 
working or not. 

 

Thanks!

 

Chris

Re: [M100] Disk for PDD2

[Jeffrey Birt]

If you have the equipment to make a disk from an image I have images of the 
TPPD1 and TPPD2 disks at: https://github.com/Jeff-Birt/TRS-80-TPDD-Images . 

I think Brian might have come up with a way to make a boot disk by attaching 
the drive to a computer via serial as well. (Some sort of Python script.)

 

Jeff Birt

 

From: M100  On Behalf Of Chris Kmiec
Sent: Thursday, September 2, 2021 4:24 PM
To: m100@lists.bitchin100.com
Subject: [M100] Disk for PDD2

 

Would someone be willing to make a copy of the 26-3814 disk for the PDD2 drive? 
I would appreciate it and will happily pay for it.

 

Thank you,

 

Chris

 

PS. I'm in Fort Mill, SC, USA

Re: [M100] New zebra strips for M100 display — any interest?

[Jeffrey Birt]

Sounds great Jamie.

 

Jeff Birt

 

From: M100  On Behalf Of Jamie Nichol
Sent: Tuesday, August 10, 2021 7:46 PM
To: m...@bitchin100.com; m...@bitchin100.com
Subject: Re: [M100] New zebra strips for M100 display — any interest?

 

Hey guys,

Quick update.  I have four displays on hand (thanks Josh!).  Measurements 
suggest a zebra strip height between 3.3mm and 3.4 mm will work best.   I’ve 
been in a protracted conversation with the supplier about best practices for 
assembly.

I’ll have another set of prototypes made at the updated height, rebuild the 
four displays I have on hand, and let you all know how that goes.

More to come,

 

—Jamie

On Jul 6, 2021, 8:25 PM -0400, Stephen Adolph mailto:twospru...@gmail.com> >, wrote:



Jamie, 

 

Are the zebra strips a problem?  I guess you are saying that for at least some 
LCDs with missing lines, a new zebra strip would help?

For me it has usually been a pcb problem.

 

Steve

 

 

 



On Tuesday, July 6, 2021, Jamie Nichol mailto:jgnic...@gmail.com> > wrote:

Hey All,

I do consumer product R as my day job.  I’ve admired the M100 as a brilliant 
product for the past decade or so, and just picked up a really sad example that 
I’m trying to resuscitate.

A couple of weeks ago I had a some fine-pitch prototype zebra strips made up to 
fit the M100 LCD (see pic).  The first prototypes are about 0.3mm too tall.  
I’ll likely have another set of prototypes run with an adjusted height.

I have two questions:

Is there enough interest here on the list to justify an order of 1000 pieces or 
so?  (Likely price is a few dollars each strip — more to come on price.)

Do any of you have dead LCDs that you would be wiling to sacrifice to the 
testing gods?  I would like to see ten or so LCDs improved by an upgrade to the 
new strips before placing a bigger order.

—Jamie

 

 

Re: [M100] Cassette woes

[Jeffrey Birt]

It is fascinating how we are all discovering new things about these machines 
30+ years after they were made.

 

Jeff Birt

 

From: M100  On Behalf Of Brian White
Sent: Wednesday, July 28, 2021 1:14 AM
To: m...@bitchin100.com
Subject: Re: [M100] Cassette woes

 

The 40mv was legit. Olivetti M10 is different than Model 100. My own machine 
and the manual itself both agree. I only get a out 30mv  myself.

 

 

bkw

 

On Tue, Jul 27, 2021, 11:37 PM Tom Wilson mailto:wilso...@gmail.com> > wrote:

I checked out my M102 on my scope, and the Peak to Peak is 624 mV. So 
definitely "line" level territory. (And the person who got 50mV PP on Facebook 
was probably using a 10x probe.)

 

 

Re: [M100] How to clean plastic?

[Jeffrey Birt]

>>But what about the white? Any suggestions on how to clean and improve its 
>>look?  Mine looks a bit yellowed

The yellow is the typically result of natural oxidation of the plastic. It can 
also be from tobacco smoke, but the stench will give that away. I usually start 
with a good washing with dish soap with a Magic Eraser used for the tough spots.

I just did a video about the yellowing process and how the 'Retr0Brite' process 
turn it back closer to the original color. With the M100 you have to deal with 
the clear plastic being stuck in place and not knowing how it will react with 
the hydrogen peroxide. 

https://youtu.be/YPl356YKcVs

Jeff Birt (Hey Birt!)

-Original Message-
From: M100  On Behalf Of Earl Baugh
Sent: Tuesday, July 27, 2021 4:47 PM
To: m100@lists.bitchin100.com
Subject: Re: [M100] How to clean plastic?


>>But what about the white? Any suggestions on how to clean and improve its 
>>look?  Mine looks a bit yellowed.   I’ll be trying some basic cleaning, but 
>>would appreciate any pointers on what others have done. 

Earl 

Re: [M100] How to clean plastic?

[Jeffrey Birt]

Like Mr. Miyagi said, “Wax on, Wax off”  

For most applications used just the medium and find products. You wipe on with 
a rag, like t-shirt material or microfiber, buff it out, and then wipe it off. 
Like with most other polishes you don’t want to work it so long that it gets 
dry.

 

Jeff

 

From: M100  On Behalf Of Jerry Davis
Sent: Monday, July 26, 2021 7:55 PM
To: m...@bitchin100.com
Subject: Re: [M100] How to clean plastic?

 

Hey, Jeff

 

What do you use to apply the polish?

 

Jerry

 

On Mon, Jul 26, 2021 at 5:06 PM Jeffrey Birt mailto:bir...@soigeneris.com> > wrote:

Are you wanting to polish the clear plastic? If so, take a look at Novus 
plastic polish. I have used it in the past, and it has worked well for me.

 

Jeff Birt

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Earl Baugh
Sent: Monday, July 26, 2021 4:40 PM
To: M100@lists.bitchin100.com <mailto:M100@lists.bitchin100.com> 
Subject: [M100] How to clean plastic?

 

Hello,

 

Got my unit back (from cap rework) and the Deox(sp?) arrived so will be trying 
to fix the POT for the brightness and the memory switch.WIll reply back 
with updates after I've done some work with that.

 

HOWEVER

 

The next question I have is what works to help restore the clear plastic over 
the display (I've heard rumors about using the headlight defog stuff for 
surfaces like that... but no idea if it's safe) and then what to do with the 
white that is both dirty and faded.   Is there a retro-brite approach?  Or 
something better?   I've had the case apart as I work on the other two parts, 
so would be a good time to work on the case...

 

Thanks!

 

Earl

 

P.S. I've got a battery and Rex ordered for the unit so those will be 
attacked after I finish with the items above...

Re: [M100] How to clean plastic?

[Jeffrey Birt]

Are you wanting to polish the clear plastic? If so, take a look at Novus 
plastic polish. I have used it in the past, and it has worked well for me.

 

Jeff Birt

 

From: M100  On Behalf Of Earl Baugh
Sent: Monday, July 26, 2021 4:40 PM
To: M100@lists.bitchin100.com
Subject: [M100] How to clean plastic?

 

Hello,

 

Got my unit back (from cap rework) and the Deox(sp?) arrived so will be trying 
to fix the POT for the brightness and the memory switch.WIll reply back 
with updates after I've done some work with that.

 

HOWEVER

 

The next question I have is what works to help restore the clear plastic over 
the display (I've heard rumors about using the headlight defog stuff for 
surfaces like that... but no idea if it's safe) and then what to do with the 
white that is both dirty and faded.   Is there a retro-brite approach?  Or 
something better?   I've had the case apart as I work on the other two parts, 
so would be a good time to work on the case...

 

Thanks!

 

Earl

 

P.S. I've got a battery and Rex ordered for the unit so those will be 
attacked after I finish with the items above...

Re: [M100] TS-DOS for Olivetti M-10

[Jeffrey Birt]

Steve,

 

The schematic looks just like the M100, down to the part names. The capacitors 
leak just like the M100 whereas the T102 caps are not a problem. 

 

The RS-232 drive section is like the M100, not the improved T102 version. The 
option ROM socket is a ‘normal’ socket and the SysBus connection is a normal 
header. Seems very much like a repackaged M100. Even the M100 test harness 
works on it. 

This is only the second one I have seen in the flesh though 

When I get it recapped I’ll burn a ROM for it and then try to bootstrap TS-DOS 
from the Backpack and see how that goes.

 

Jeff

 

From: M100  On Behalf Of Stephen Adolph
Sent: Monday, July 26, 2021 1:15 PM
To: m...@bitchin100.com
Subject: Re: [M100] TS-DOS for Olivetti M-10

 

Cool Jeff,

I would value your feedback. I have noticed a couple of things to fix on the 
keyboard mapping.  Please share any things you find that are broken.

Also, I know you have a keenly tuned hardware eye. I think that it is just the 
keyboard that is different.  Do you see any other items?

cheers

Steve

 

Re: [M100] TS-DOS for Olivetti M-10

[Jeffrey Birt]

That is even better! Thanks Steve.

 

Jeff

 

From: M100  On Behalf Of Stephen Adolph
Sent: Monday, July 26, 2021 12:54 PM
To: m...@bitchin100.com
Subject: Re: [M100] TS-DOS for Olivetti M-10

 

http://bitchin100.com/wiki/index.php?title=Olivetti_M10_ROM_patch

 

pretty skinny docs... 

What use it has had, has been favorable.

 

the patch is documented however, and if there are issues we can always update 
the patch.

 

http://club100.org/memfiles/index.php?direction= 
<http://club100.org/memfiles/index.php?direction===Steve%20Adolph/Patched%20M10%20Main%20ROM;>
 ==Steve%20Adolph/Patched%20M10%20Main%20ROM&

 

Steve

 

On Mon, Jul 26, 2021 at 1:50 PM Stephen Adolph mailto:twospru...@gmail.com> > wrote:

Jeff,

I cant help on an M10 tsdos, but are you aware that i patched an m100 main to  
to run in an m10?  

This gives you all the roms in an m10. 

 

Steve


On Monday, July 26, 2021, Jeffrey Birt mailto:bir...@soigeneris.com> > wrote:

Hi all,

 

I recently picked up an Olivetti M-10 which is just a bit different than the 
M100. I have been looking for a version of TS-DOS for it but have not found 
such a beast. Has anyone ever patched TS-DOS for the M-10?

 

Thanks,

Jeff Birt 

[M100] TS-DOS for Olivetti M-10

[Jeffrey Birt]

Hi all,

 

I recently picked up an Olivetti M-10 which is just a bit different than the
M100. I have been looking for a version of TS-DOS for it but have not found
such a beast. Has anyone ever patched TS-DOS for the M-10?

 

Thanks,

Jeff Birt 

Re: [M100] Tpdd reassemble

[Jeffrey Birt]

I like to put a strip of painters tape over the buttons before taking the front 
cover off. This will keep them in place for reassembling.

 

Jeff Birt

 

From: M100  On Behalf Of Jesse Lafleur
Sent: Thursday, July 22, 2021 11:16 PM
To: Model 100 Discussion 
Subject: [M100] Tpdd reassemble

 

Yup. I iknew it would be difficult but i did it anyway... ive got the brother 
rebadge. I opened it to check the belt.

 

Any tips or suggestions on getting everything back together? Just the 
case/button/cover itself, not the internal drive.

 

Most obliged

Re: [M100] Floppy Disc Drive Motor

[Jeffrey Birt]

I have not torn my DVI apart yet, so I have not seen the drive up close.
Guessing it is a BLDC type, i.e. direct drive, not blet drive. I might try
to remove the spinning part of the motor (probably part you are giving a
push) and lubricate whatever bearings/bushings its shaft goes through. (Just
thinking out loud not having seen this drive in person.)

 

Jeff Birt

 

From: M100  On Behalf Of
jaa...@sbcglobal.net
Sent: Wednesday, July 21, 2021 9:41 PM
To: m100@lists.bitchin100.com
Subject: [M100] Floppy Disc Drive Motor

 

Hi All,

 

Fairly new here but have been enjoying the discussion and learning a lot.

 

I am fixing a Disc/Video interface for use with my model 100.  I've got
everything working fine now except I have to reach in and give the spindle
motor on the floppy disc drive a "push" from underneath with my finger in
order to get it started.  Once it's spinning it's fine and everything loads,
but any time the motor stops (like after it reads a disc), I have to do the
same thing over again, which is of course not very convenient.

 

I'm assuming this is a standard drive among Tandy equipment.  Curious if
anyone who has a similar FDD has run into the same issue or has any advice.

 

Thanks much,

 

James Copeland

[M100] Differences in M100 / T102 serial output driving

[Jeffrey Birt]

In the course of troubleshooting a perceived serial port problem on my M100
I found that when the DTR/DSR was looped back (and asserted) the voltage at
the DTR/DSR junction was 2.7V and the input voltage at M35 was only +1V.
There was 2V dropped across the 5.6K series resistor on the DTR output. 

 

Testing DTR/DSR loopback on the T102 and there is no issue. The voltage at
the DTR/DSR junction was about 4.5V as one would expect. 

 

Comparing the schematics of the two revealed the reason. The T102 has a much
beefier output drive. Not only did they double up the output drivers they
dropped the series resistor to 330ohms! That us a HUGE change which makes me
suspect that there was reliability issues they were trying to fix. 

 

I know folks have had different success with various baud rates, for some
higher rates seem to work OK but not for others and I wonder if this 'weak
tea' drive on the three serial output lines is part of the issue. I think
changing the 5.6K resistor with something like a 1.27K would take care of
the issue and still be half the current that each of the drivers in the T102
are handling. (One could also take a suitable resistor in parallel with the
existing one of the PCB as a quick fix without removing the PCB.)

 

It would be interesting to find a test case where this can be tried with the
TX line only, ignoring the handshaking signals.

Jeff Birt

Re: [M100] Sneak peak and small first offering of the new 'Backpack Drive'

[Jeffrey Birt]

If anyone is curious about the PLA used it is from PrintedSolid.com, Jessie PLA 
1.75mm X Beige 500. I like to call it ‘old computer beige’.

 

Jeff Birt (Hey Birt!)

 

From: M100  On Behalf Of Kevin Becker
Sent: Friday, July 16, 2021 10:05 AM
To: m...@bitchin100.com
Subject: Re: [M100] Sneak peak and small first offering of the new 'Backpack 
Drive'

 

It's really cool, I like it a lot.  The PLA you used for the case is a really 
close match to my T102, which is cool too.

 

Re: [M100] Sneak peak and small first offering of the new 'Backpack Drive'

[Jeffrey Birt]

Hi,

 

The bootstrapping works nice, albeit a bit slow. The Initial Program Loader 
figures out what computer you are using a sends a numerical code to the 
Backpack. It uses the number as an index into the boot sector table to know 
which bootstrap program to use. You can change these settings in the CLI so you 
can load TS-DOS for the M100, or Teeny, etc. The developer just came up with a 
smaller bootstrap that will load in the .CO version of TS-DOS directly which 
should work better for machines with less RAM. We’ll test it out a bit more and 
then add it to GitHub.

 

Jeff

 

From: M100  On Behalf Of Kevin Becker
Sent: Thursday, July 15, 2021 4:23 PM
To: m...@bitchin100.com
Subject: Re: [M100] Sneak peak and small first offering of the new 'Backpack 
Drive'

 

I got a chance to play with my Backpack Drive today for a little bit.  So far 
I'm really happy with it.  It's seems to work great and be pretty easy to use.  
I was only testing on a device with a REX, so I already have TS-DOS but I'm 
really thinking with the built-in bootstrapping, it will be nice for one of my 
other systems with no REX. I haven't tested that yet though.

 

 

 

On Sun, 2021-07-04 at 07:44 -0500, Jeffrey Birt wrote:

Hi all,

 

A friend and fellow list member has developed a SD card storage solution for 
the M100, T102, WP-2 NECs, etc. He sent me one a few months ago and I loved it 
so much I encouraged him to offer them up for sale. It is a small device, about 
25mmx40mmx75mm with the case on. It runs from a single AA battery with a 1025 
coin cell to run the RTC (the RTC allows for time/date stamping file). It works 
like a TPPD2 but ignores calls to change partitions. All TS-DOS commands are 
supported including directory navigation. It also has an extensive CLI 
interface which makes it easy to do things like set the time/date, update 
firmware, etc. 

Hi Everyone. We have a small number of the mini TPDD 'Backpack' drives ready 
for a new home. The documentation has been poured over by four of us, but I am 
sure there are still a few rough edges. Much thanks go out to @48kRAM and 
@Fezzler for helping to improve the documentation and being beta testers. There 
is a Git Hub page up now: https://github.com/Jeff-Birt/Backpack which has lots 
of images too.

I have offered to handle distribution as I am already set up to do so.

 

This first small batch is completely assembled, and it comes with a 3D printed 
enclosure. You will need an AA battery and a smallish SD card, i.e. 4GB, 8GB, 
etc. There are images of the enclosure colors at the link above. The main 
colors are white, grey, and ‘old computer beige’ I did print a case in black 
and one in a pearlescent color that is kind of interesting. The price is $60. 

 

If you want to use it with a WP2 you need a DB25F<->DB9F adapter, The developer 
of the 'Backpack' found a small number of NOS Belkin adapters on eBay and is 
selling them at his cost, $5 in case someone needs one. He also laid up a small 
PCB so folks can build their own if they want. The links to the PCB files will 
be available shortly.

 

Shipping in the USA is $5.50 for one unit, about $7.00 with the adapter by 
first class mail. By Priority Mail it will be $9 for a Small Flat Rate box.  
For international orders I’ll need to your address to get shipping rates.  To 
make thing easier email me directly with your email address, shipping address, 
color of case and if you want an adapter for the WP2. I'll send out a PayPal 
invoice.

 

Keep in mind we have a small number in this first batch let’s give everyone a 
chance to get one. A second small batch of hand assembled boards will be 
available in the near future.

Jeff Birt (Hey Birt!)

 

Re: [M100] Burn in program

[Jeffrey Birt]

Thanks Jerry, reading the entire address range is a good idea so that the whole 
address bus and all memory is exercised. I added in clearing TIME$ first, and 
then printing it after the CLS. I also snuck in a BEEP before the GOTO per 
Josh’s suggestion.

It takes 25:07 to walk the entire address range and print out all characters 
>=32 





10 TIME$=”00:00:00”
20 CLS:PRINT TIME$;”  “;

30 FOR N=0 TO 65535

40 X=PEEK(N)

50 IF X < 32 THEN 70

60 PRINT CHR$(X);

70 NEXT N
80 BEEP

90 GOTO 20

 

Jeff

 

From: M100  On Behalf Of Jerry Davis
Sent: Saturday, July 10, 2021 11:59 AM
To: m...@bitchin100.com
Subject: Re: [M100] Burn in program

 

Hey, Jeff

 

Its nothing like a real exorciser but I've been running the following code on 
BASIC language machines since I was a kid to see how the machine will respond 
and how long it will run.  It's more fun to watch than anything else.

 

10 CLS

20 FOR N=0 TO 65535

30 X=PEEK(N)

40 IF X < 32 THEN 60

50 PRINT CHR$(X);

60 NEXT N

70 GOTO 10

 

Machines with memory mapped I/O don't appear to be adversely affected by reads 
on their ports.  I've run it on machines with serial consoles (polled mode), 
disk drive controllers, etc.

 

I was working on a 6809 machine running Flex09 that would crash intermittently 
when running a BASIC program.  The above program would lock up the machine in a 
few minutes to a few hours.  The RAM pattern test utility would crash faster 
than I could get a scope on it.  I finally found the glitch in a RAM select 
line and fixed it.  The RAM pattern test ran clear.  Then I ran this program 
for a few days without a lockup and called it fixed.

 

Jerry

 

 Original message ----

From: Jeffrey Birt mailto:bir...@soigeneris.com> > 

Date: 7/9/21 7:59 PM (GMT-06:00) 

To: m...@bitchin100.com <mailto:m...@bitchin100.com>  

Subject: [M100] Burn in program 

 

Hi all,

 

Burn in test? I was just wondering what sort of program you guys like to run as 
a burn in test of a computer you have just repaired. I modified the M100 test 
harness code so can run a continuous RAM test but that is not a really useful 
test that everyone can use as it only works with the test harness.

 

Maybe something in BASIC that just runs some calculations, displays things on 
the LCD, etc. to test how stable the computer is when running for a few hours. 
Any favorites?

 

Thanks,

Jeff Birt

 

 Original message ----From: Jeffrey Birt mailto:bir...@soigeneris.com> > Date: 7/9/21  7:59 PM  (GMT-06:00) To: 
m...@bitchin100.com <mailto:m...@bitchin100.com>  Subject: [M100] Burn in 
program Hi all, Burn in test? I was just wondering what sort of program you 
guys like to run as a burn in test of a computer you have just repaired. I 
modified the M100 test harness code so can run a continuous RAM test but that 
is not a really useful test that everyone can use as it only works with the 
test harness. Maybe something in BASIC that just runs some calculations, 
displays things on the LCD, etc. to test how stable the computer is when 
running for a few hours. Any favorites? Thanks,Jeff Birt

Re: [M100] Burn in program

[Jeffrey Birt]

The beep is a great idea! I think this one was a simple, but it was 
intermittent for the owner and just happened to quit completely on its way to 
me. The memory protect switch was gummed up not making good contact. Luckily is 
was completely open when it got to me so it was easy to track down. 

Jeff

-Original Message-
From: M100  On Behalf Of Josh Malone
Sent: Saturday, July 10, 2021 11:10 AM
To: m...@bitchin100.com
Subject: Re: [M100] Burn in program

Last time I had an unstable machine, I just used a quick basic program with 
POWER CONT, a delay loop, a cycle counter, and BEEP (so I could notice across 
the house when it had died). But, in my case, I knew (or, STRONGLY suspected) 
that the fault was in the power supply and that the rest of the machine was 
likely fine.

On Fri, Jul 9, 2021 at 8:59 PM Jeffrey Birt  wrote:
>
> Hi all,
>
>
>
> Burn in test? I was just wondering what sort of program you guys like to run 
> as a burn in test of a computer you have just repaired. I modified the M100 
> test harness code so can run a continuous RAM test but that is not a really 
> useful test that everyone can use as it only works with the test harness.
>
>
>
> Maybe something in BASIC that just runs some calculations, displays things on 
> the LCD, etc. to test how stable the computer is when running for a few 
> hours. Any favorites?
>
>
>
> Thanks,
>
> Jeff Birt
>
>

[M100] Burn in program

[Jeffrey Birt]

Hi all,

 

Burn in test? I was just wondering what sort of program you guys like to run
as a burn in test of a computer you have just repaired. I modified the M100
test harness code so can run a continuous RAM test but that is not a really
useful test that everyone can use as it only works with the test harness.

 

Maybe something in BASIC that just runs some calculations, displays things
on the LCD, etc. to test how stable the computer is when running for a few
hours. Any favorites?

 

Thanks,

Jeff Birt

 

Re: [M100] is the mailing list acting strangely?

[Jeffrey Birt]

It's a ripple in the time/space continuum thing 

Jeff Birt

-Original Message-
From: M100  On Behalf Of Josh Malone
Sent: Friday, July 9, 2021 8:04 AM
To: m...@bitchin100.com
Subject: Re: [M100] is the mailing list acting strangely?

Nope - not just you. I get replied often before I get the original question. I 
assumed it was something with gmail, but it could also be the mailman queue 
processing.

On Fri, Jul 9, 2021 at 8:57 AM Stephen Adolph  wrote:
>
> I'm finding that emails seem to be missing from threads, delivered out of 
> order etc.
> just me?
>

Re: [M100] Must-have ROMs

[Jeffrey Birt]

I use a TL866 which is a pretty good and lower cost unit. 

 

Jeff Brt

 

From: M100  On Behalf Of Jeff Gonzales
Sent: Thursday, July 8, 2021 8:24 AM
To: m...@bitchin100.com
Subject: Re: [M100] Must-have ROMs

 

What gear do you need to burn your own ROMs?  I didn't even think the chips 
would still be available in the 21st century.

 

On Thu, Jul 8, 2021 at 9:14 AM Justin Poirier mailto:gen.ele...@gmail.com> > wrote:

I’ve been using my M102 (and later as $$$ allowed, M200s) since the early ‘90s, 
but have just gotten into burning my own ROMs for the ROM slot, now that I’m in 
a position to fabricate the carrier boards. I’ve found a half-dozen ROM images 
(separate images for both the 100/102 and the 200), but no real descriptions of 
what I should be looking into. TS-DOS is a must-have since I have a disk drive, 
and that works great, but Sardine, Random, etc all look like they need 
additional “support” ROMs, or extra hardware, or are application-specific in a 
direction unknown to me. Are there other ROM images that most people find 
useful, or are part of the “must-have” collection? Where do I find them, if 
they exist?

I realize I’ve just asked a question like “what is the best brand of motor oil” 
on a car-enthusiasts forum, but if anyone could throw me a bone and get me 
pointed in a good direction, I’m pretty good at finding the rest of the details 
myself.

Thanks a lot!

—Justin

[M100] Backpack drive quick start

[Jeffrey Birt]

Hi all,

 

Here is the promised Quick Start video for the Backpack drive. They have all
been spoken for at this point but if you are interested in one let me know
so we can get an idea of how many to have made up on the production line.

 

This video is intended as a 'quick start' of sorts, to get you up and
running quickly. More videos will be coming where we will dig into advanced
features.

 

https://youtu.be/3es0NLJmd2c

 

Jeff Birt (Hey Birt!)

Re: [M100] New zebra strips for M100 display ? any interest?

[Jeffrey Birt]

I will also pick some up to have on hand, just in case. If I can help test let 
me know.

 

Jeff Birt

 

 

From: M100  On Behalf Of Jamie Nichol
Sent: Wednesday, July 7, 2021 4:39 PM
To: Model 100 Discussion ; m...@bitchin100.com
Subject: Re: [M100] New zebra strips for M100 display ? any interest?

 

Peter,

Looks like a pair of new zebra strips will cost $6 with usps shipping to 
contiguous USA.

Manufacturer is fujipoly.  Better quality supplier.

I’d love to sign you up for a dozen, once testing looks good.

Anyone else interested at this price?


—Jamie

On Jul 7, 2021, 5:28 PM -0400, Peter Noeth mailto:petern0...@gmail.com> >, wrote:

My experience with zebra strips, in general are threefold:
 1. The silicon can "outgas" its oils over time, if they were not baked 
correctly at manufacture. This oil can contaminate the carbon layers on the 
"face ends" where the strip contacts the glass / PCB, causing open connections. 
 2. The face ends of the carbon layers are not always friendly to cleaning. The 
conductivity of the carbon layers can be lost, especially after 5 years.
 3. The silicon can lose its elasticity, causing open connections. This mostly 
manifests itself during reassembly of an LCD display module if reusing the 
original zebra strips. Especially after 40 years of questionable storage 
conditions.
When disassembly of an LCD display module was necessary, new zebra strips were 
always used during reassembly. This just removes a lot of potential problems, 
especially if you warrant your work.

So having a source for replacement zebra strips for the notebook computers 
would be handy, but at a minimum production quantity of 1000, you would 
probably still have 800 when you die. Maybe not economical, from a business 
investment, but maybe from a passion standpoint.

I would buy a dozen :-)

Regards,

Peter

--

Message: 3
Date: Tue, 6 Jul 2021 19:33:53 -0400
From: Jamie Nichol https://mailto:jgnic...@gmail.com> >
To: m...@bitchin100.com  Subject: [M100] 
New zebra strips for M100 display
=?utf-8?Q?=E2=80=94_?=any interest?
Message-ID: 
Content-Type: text/plain; charset="utf-8"

Hey All,

I do consumer product R as my day job.??I?ve admired the M100 as a brilliant 
product for the past decade or so, and just picked up a really sad example that 
I?m trying to resuscitate.

A couple of weeks ago I had a some fine-pitch prototype zebra strips made up to 
fit the M100 LCD (see pic).??The first prototypes are about 0.3mm too 
tall.??I?ll likely have another set of prototypes run with an adjusted height.

I have two questions:

Is there enough interest here on the list to justify an order of 1000 pieces or 
so???(Likely price is a few dollars each strip ? more to come on price.)

Do any of you have dead LCDs that you would be wiling to sacrifice to the 
testing gods???I would like to see ten or so LCDs improved by an upgrade to the 
new strips before placing a bigger order.

?Jamie


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Re: [M100] M100 / 102 Wanted

[Jeffrey Birt]

If you decide you want to try and get it fixed let me know.

 

Jeff

 

 

From: M100  On Behalf Of
lloydel...@comcast.net
Sent: Wednesday, July 7, 2021 1:03 PM
To: m...@bitchin100.com
Subject: Re: [M100] M100 / 102 Wanted

 

Thanks for the information.   What you are describing sounds a bit more
intense than what I'm willing to try at this time.An option I might
consider in the future is to sell it as is and try and acquire one without
any display problems.  I understand that as time marches on, such an
acquisition might be difficult but I guess that is a risk.

 

As I mentioned, I can live with it as is (at least for now).

 

Lloyd

 

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Jeffrey Birt
Sent: Wednesday, July 7, 2021 6:38 AM
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] M100 / 102 Wanted

 

The partial missing column is one driver output's worth. That might just be
a bad contact or a bad driver chip. The missing row troubles me more as it
could signal a bad LCD glass. I have a T102 that has the same symptom and
tracked it down to the glass. Interestingly the LCD glass is laid out
symmetrically. You can take it out of the frame and rotate 180degrees and if
the horizontal line is also moved you know you have a bad glass. Getting the
LCD glass lined up correctly on the PCB when putting it all back together
can be tricky though.

 

Jeff Birt

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of
lloydel...@comcast.net <mailto:lloydel...@comcast.net> 
Sent: Tuesday, July 6, 2021 8:42 PM
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] M100 / 102 Wanted

 

The problem is annoying but it is something I can live with.   I attached a
picture illustrating the problem.

 

On the picture, you can see that the top of the 6th line has a horizontal
roll of pixels out.  It is most noticeable on the number, "5" where it took
out the top of this number.

 

The vertical column of dead pixels is on the column labeled, "Dist".   It
affects the first four lines of the display and you can see where the
number, "9" is affected.

 

Lloyd

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Jeffrey Birt
Sent: Tuesday, July 6, 2021 6:00 PM
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] M100 / 102 Wanted

 

Bum LCDs are often the most difficult thing to fix. If the problem is a
corroded connection to the LCD glass there is a 50/50 chance of fixing it
and getting the glass lined back up properly. I have also seen a missing
horizontal line be due to a bad LCD glass. The driver ICs can also fail and
they have to be scrounged from other LCDs are they are an odd/smaller
package that seems to be unique to the M100/T102.

 

Jeff Birt

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of
lloydel...@comcast.net <mailto:lloydel...@comcast.net> 
Sent: Tuesday, July 6, 2021 3:47 PM
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] M100 / 102 Wanted

 

I wish I had known about this group prior to forking over $200 to eBay for a
M100 in "mint" condition.

 

The seller's definition of "mint" differed a bit from mine in that a
horizontal row of pixels is out and there is a column of pixels that is out
for the top 1/3 of the column.

 

Do you fix these and if so, how much would it cost?   The Y2K updated ROM
sounds useful as well.

 

Lloyd

 

Re: [M100] M100 / 102 Wanted

[Jeffrey Birt]

The partial missing column is one driver output's worth. That might just be
a bad contact or a bad driver chip. The missing row troubles me more as it
could signal a bad LCD glass. I have a T102 that has the same symptom and
tracked it down to the glass. Interestingly the LCD glass is laid out
symmetrically. You can take it out of the frame and rotate 180degrees and if
the horizontal line is also moved you know you have a bad glass. Getting the
LCD glass lined up correctly on the PCB when putting it all back together
can be tricky though.

 

Jeff Birt

 

From: M100  On Behalf Of
lloydel...@comcast.net
Sent: Tuesday, July 6, 2021 8:42 PM
To: m...@bitchin100.com
Subject: Re: [M100] M100 / 102 Wanted

 

The problem is annoying but it is something I can live with.   I attached a
picture illustrating the problem.

 

On the picture, you can see that the top of the 6th line has a horizontal
roll of pixels out.  It is most noticeable on the number, "5" where it took
out the top of this number.

 

The vertical column of dead pixels is on the column labeled, "Dist".   It
affects the first four lines of the display and you can see where the
number, "9" is affected.

 

Lloyd

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Jeffrey Birt
Sent: Tuesday, July 6, 2021 6:00 PM
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] M100 / 102 Wanted

 

Bum LCDs are often the most difficult thing to fix. If the problem is a
corroded connection to the LCD glass there is a 50/50 chance of fixing it
and getting the glass lined back up properly. I have also seen a missing
horizontal line be due to a bad LCD glass. The driver ICs can also fail and
they have to be scrounged from other LCDs are they are an odd/smaller
package that seems to be unique to the M100/T102.

 

Jeff Birt

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of
lloydel...@comcast.net <mailto:lloydel...@comcast.net> 
Sent: Tuesday, July 6, 2021 3:47 PM
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] M100 / 102 Wanted

 

I wish I had known about this group prior to forking over $200 to eBay for a
M100 in "mint" condition.

 

The seller's definition of "mint" differed a bit from mine in that a
horizontal row of pixels is out and there is a column of pixels that is out
for the top 1/3 of the column.

 

Do you fix these and if so, how much would it cost?   The Y2K updated ROM
sounds useful as well.

 

Lloyd

 

Re: [M100] New zebra strips for M100 display — any interest?

[Jeffrey Birt]

That is quite the initiative. I’m not sure how many LCD problems are related to 
zebra strips. Of the ones I have had with problem with or helped diagnose

 

a.  Corroded contact pad and bad LCD glass, one row was bad, you can turn 
glass 180 to verify.
b.  Bad driver chip

 

Not a big sample size. No doubt some others are zebra strip related. I have 
only heard a few rumblings about zebra strips on the various forums and such 
too. If I were to try swapping an M100 LCD glass into a T102 for example I 
might go ahead and install new zebra strips to be safe, so I don’t have to pull 
it back apart multiple times to mess with the original one. 

It might take 3-5 years to find enough folks who need to be zebra strips for 
M100s to go through 1,000 which is something to consider when you are tying up 
your money upfront to purchase them. I have commissioned a few reproduction 
parts for old computers now and just want to pass along what I have learned.   

 

Jeff Birt

 

From: M100  On Behalf Of Jamie Nichol
Sent: Tuesday, July 6, 2021 6:34 PM
To: m...@bitchin100.com
Subject: [M100] New zebra strips for M100 display — any interest?

 

Hey All,

I do consumer product R as my day job.  I’ve admired the M100 as a brilliant 
product for the past decade or so, and just picked up a really sad example that 
I’m trying to resuscitate.

A couple of weeks ago I had a some fine-pitch prototype zebra strips made up to 
fit the M100 LCD (see pic).  The first prototypes are about 0.3mm too tall.  
I’ll likely have another set of prototypes run with an adjusted height.

I have two questions:

Is there enough interest here on the list to justify an order of 1000 pieces or 
so?  (Likely price is a few dollars each strip — more to come on price.)

Do any of you have dead LCDs that you would be wiling to sacrifice to the 
testing gods?  I would like to see ten or so LCDs improved by an upgrade to the 
new strips before placing a bigger order.

—Jamie

 

 

Re: [M100] M100 / 102 Wanted

[Jeffrey Birt]

Bum LCDs are often the most difficult thing to fix. If the problem is a
corroded connection to the LCD glass there is a 50/50 chance of fixing it
and getting the glass lined back up properly. I have also seen a missing
horizontal line be due to a bad LCD glass. The driver ICs can also fail and
they have to be scrounged from other LCDs are they are an odd/smaller
package that seems to be unique to the M100/T102.

 

Jeff Birt

 

From: M100  On Behalf Of
lloydel...@comcast.net
Sent: Tuesday, July 6, 2021 3:47 PM
To: m...@bitchin100.com
Subject: Re: [M100] M100 / 102 Wanted

 

I wish I had known about this group prior to forking over $200 to eBay for a
M100 in "mint" condition.

 

The seller's definition of "mint" differed a bit from mine in that a
horizontal row of pixels is out and there is a column of pixels that is out
for the top 1/3 of the column.

 

Do you fix these and if so, how much would it cost?   The Y2K updated ROM
sounds useful as well.

 

Lloyd

 

[M100] Sneak peak and small first offering of the new 'Backpack Drive'

[Jeffrey Birt]

Hi all,

 

A friend and fellow list member has developed a SD card storage solution for
the M100, T102, WP-2 NECs, etc. He sent me one a few months ago and I loved
it so much I encouraged him to offer them up for sale. It is a small device,
about 25mmx40mmx75mm with the case on. It runs from a single AA battery with
a 1025 coin cell to run the RTC (the RTC allows for time/date stamping
file). It works like a TPPD2 but ignores calls to change partitions. All
TS-DOS commands are supported including directory navigation. It also has an
extensive CLI interface which makes it easy to do things like set the
time/date, update firmware, etc. 

Hi Everyone. We have a small number of the mini TPDD 'Backpack' drives ready
for a new home. The documentation has been poured over by four of us, but I
am sure there are still a few rough edges. Much thanks go out to @48kRAM and
@Fezzler for helping to improve the documentation and being beta testers.
There is a Git Hub page up now: https://github.com/Jeff-Birt/Backpack which
has lots of images too.

I have offered to handle distribution as I am already set up to do so.

 

This first small batch is completely assembled, and it comes with a 3D
printed enclosure. You will need an AA battery and a smallish SD card, i.e.
4GB, 8GB, etc. There are images of the enclosure colors at the link above.
The main colors are white, grey, and 'old computer beige' I did print a case
in black and one in a pearlescent color that is kind of interesting. The
price is $60. 

 

If you want to use it with a WP2 you need a DB25F<->DB9F adapter, The
developer of the 'Backpack' found a small number of NOS Belkin adapters on
eBay and is selling them at his cost, $5 in case someone needs one. He also
laid up a small PCB so folks can build their own if they want. The links to
the PCB files will be available shortly.

 

Shipping in the USA is $5.50 for one unit, about $7.00 with the adapter by
first class mail. By Priority Mail it will be $9 for a Small Flat Rate box.
For international orders I'll need to your address to get shipping rates.
To make thing easier email me directly with your email address, shipping
address, color of case and if you want an adapter for the WP2. I'll send out
a PayPal invoice.

 

Keep in mind we have a small number in this first batch let's give everyone
a chance to get one. A second small batch of hand assembled boards will be
available in the near future.

Jeff Birt (Hey Birt!)

 

Re: [M100] Remove m102 screen

[Jeffrey Birt]

Just to be clear, I did not suggest a heat gun, most of them would produce too 
much heat. Rather I suggest a hair dryer which will be hot enough to soften the 
adhesive but will not get hot enough to damage the plastic. AS Peter says, if 
you don’t need to remove it then that removes the risk of damaging it or the 
case.

 

Jeff Birt

 

From: M100  On Behalf Of Peter Noeth
Sent: Sunday, June 6, 2021 4:55 PM
To: Model 100 Discussion 
Subject: Re: [M100] Remove m102 screen

 

Mine was held on by strips of double sided tape (VHB). Sparing use of a heat 
gun as Birt suggests might work, but you risk delamination of the "Black Mask" 
when the tape releases.

 

If the purpose in removing the lens is to polish out scratches, then it is best 
to mask over the rest of the top case with 2 layers of painters tape. If you 
are trying to "Retrobright" the top case to remove yellowing, then the group 
experience is that the lens is safe from the process, but best to cover with 
painters tape as a safeguard.

 

Regards,

 

Peter

 

On Sun, Jun 6, 2021 at 2:33 PM mailto:m100-requ...@lists.bitchin100.com> > wrote:


--

Message: 1
Date: Sat, 5 Jun 2021 18:48:05 -0400
From: Scott Lawrence mailto:yor...@gmail.com> >
To: Model 100 Discussion mailto:m100@lists.bitchin100.com> >
Subject: [M100] Remove m102 screen
Message-ID: mailto:f4455626-c9fc-41db-877f-302123240...@gmail.com> >
Content-Type: text/plain; charset="us-ascii"

Is there a non-destructive way to remove the transparent LCD protector from the 
top case of the M102?  It seems to be glued in.  I haven't really tried 
anything yet other than twisting the enclosure to try to pop it off.

anyone have any thoughts?

-- 
Scott Lawrence
yor...@gmail.com  

Re: [M100] Remove m102 screen

[Jeffrey Birt]

I would try heating the area, from the rear with a hair dryer. This should 
soften the glue enough to allow popping it out. For a bit more protection of 
the plastic you could cover the exposed part of the window with painter’s tape. 
The idea is to get it warm, maybe 30C~40C but not so hot as to cause distortion.

 

Jeff

 

From: M100  On Behalf Of Scott Lawrence
Sent: Saturday, June 5, 2021 5:48 PM
To: Model 100 Discussion 
Subject: [M100] Remove m102 screen

 

Is there a non-destructive way to remove the transparent LCD protector from the 
top case of the M102?  It seems to be glued in.  I haven't really tried 
anything yet other than twisting the enclosure to try to pop it off.

 

anyone have any thoughts?

 

-- 

Scott Lawrence
yor...@gmail.com  

 

Sent from your iPhone.

Re: [M100] TPDD2 & Cambridge z88

[Jeffrey Birt]

I would be interested in the TPDD2 but would need it shipped to Missouri.

 

Jeff Birt

 

From: M100  On Behalf Of Francois Gurin
Sent: Wednesday, May 19, 2021 7:14 PM
To: m...@bitchin100.com
Subject: [M100] TPDD2 & Cambridge z88

 

Some time back I replaced the belt and had my TPDD2 working fine until it took 
a tumble while accessing the disk.  It tries to read and write, but throws 
device errors.  For the life of me, I can't figure out what is wrong.  I got 
very excited by the service manual but haven't made headway. 

 

Does anyone have a good home for it?  I'd love for someone local to NYC swing 
by and carry it off, but am willing to ship if you cover postage.  Just the 
drive.  If I have to ship, keep in mind that I am slow at packing things up and 
sending them out.

 

Completely unrelated, I  have a Cambridge Z88 with a broken screen, any chance 
one of you have either a replacement screen or a busted one with a possibly 
salvageable screen?

 

 

Re: [M100] Other things that used the Molex socket

[Jeffrey Birt]

I don’t understand your question re: C64 ROMs. They are all 24 pin, and not a 
‘standard’ or ’common’ EPROM pinout although some compatible EPROMs were 
available at the time. As I mentioned Commodore was producing these chips en 
masse so they did not care, better to cut the extra 4 unneeded pins and reduce 
the cost. The C128 used a ‘standard’ or ‘common’ pinout though, the factory 
would often use EPROMs when they ran out of masked ROMs for these machines.

The PC-1500 ROM is ‘odd’ compared to a plain vanilla ROM as we see most often. 
As I said these were done to suit the needs of the manufacturer to reduce 
external decode logic. My point here was that manufactures will made ROMs that 
were not ‘standard’ or ‘common’.

I am aware that masked ROMS are custom parts, that was never in question. My 
original premise was that IF Kyocera had made the pinout of the optROM socket 
compatible with a standard EPROM pinout of the era it would have been much 
easier for 3rd parties to release software that way. It made little sense to 
make the optROM socket pinout not match a ‘standard’ or ‘common’ EPROM pinout.

Judging by the fact Kyocera used standard pinouts on other models like the M10, 
PC-8201, etc. maybe they saw this was a better route to go? Maybe it was Tandy 
who insisted on the funky optROM socket to try and have a lock on the software? 

 

Jeff Birt

 

From: M100  On Behalf Of Mike Stein
Sent: Wednesday, May 19, 2021 10:32 AM
To: m...@bitchin100.com
Subject: Re: [M100] Other things that used the Molex socket

 

Hi Jeff,

 

if the ROMs in a C64 have a 'non-standard' pinout, what is the 'standard' 
pinout for a 24-pin 64Kb ROM and how are the C64 ROMs and compatible EPROMs 
different? I think the only 'non-standard' ROM is the character generator but 
it's used in the 'standard' way AFAIR.

 

It's not really relevant to the 64Kb C64 ROMs but when you talk about a 
'standard' are you talking about the pinout or the pin function? By definition 
mask-programmed ROMs are all custom parts; not only did you specify the data 
contents but for many ROMs you could also specify the chip select polarities, 
so it could have a standard pinout but custom select logic. Your PC1500 ROM 
isn't really that odd; it was not unusual to use multiple selects for partial 
address decoding and in fact if you look at other Commodore products for 
example you'll see the same technique used. Even though the pinout may be the 
same, those ROMs can not be replaced with an EPROM without an adapter.

 

I wonder if the non-standard pinout in the old M100 and the matching option ROM 
was meant as a form of copy protection; I guess for compatibility they had to 
keep the option ROM pinout even after switching to the JEDEC standard in the 
system ROM.

 

On Wed, May 19, 2021 at 9:46 AM Jeffrey Birt mailto:bir...@soigeneris.com> > wrote:

I really doubt MS had anything to do with the ROM pinout. There were several 
different ROM pinouts back in the day, every manufacture had their own take on 
it to suit their own needs. For example, all the ROMs in a C64 have a 
nonstandard pinout. You could get EPROMs to match back in the day, but they 
were far less common. But Commodore was mass producing them in house so they 
did not care.

I am looking at a Sharp LH5367 ROM at this very moment from the PC-1500. It is 
very odd, it has a whole raft of chip selects/chip enables some of which are 
active high, some are active low. This was done to suit the application they 
were used in to reduce external decoding logic. 

The ROM inside the original M100 is just a Sharp made, Sharp pinout part. There 
was no need for them to make the option ROM socket an odd pinout just because 
they used this Sharp ROM inside. As I mentioned I think Kyocera figured this 
out fast and went to standard sockets and pinout in later models when they saw 
the uses the machines were put to. Nothing to do with Microsoft.

 

Jeff Birt

 

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Stephen Adolph
Sent: Wednesday, May 19, 2021 7:45 AM
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] Other things that used the Molex socket

 

Tandy did release software using the strange socket. Multi-solutions for one, 
multiplan for another.The M100 main ROM also used the strange pinout. 

 

Didn't Microsoft supply the programmed M100 Main ROM PROMs to Tandy?   I think 
I read this somewhere, and in fact they released the PROMs with "Microsoft" all 
over the interface, against Tandy wishes.  Tandy was forced to release as is.

 

If this is true then I suspect Tandy had to implement the interface as per the 
agreement with Microsoft (which would have included pinout).

In later versions, they clearly got away from Microsoft 'shackles'.

 

In the end, I don't think Tandy 'chose' the pinout.  I think it was pushed on 
them by Bill.

 

 

On Wed, May 19, 2021 at 8:34 AM Jeffrey Birt mailto:bi

Re: [M100] Other things that used the Molex socket

[Jeffrey Birt]

I really doubt MS had anything to do with the ROM pinout. There were several 
different ROM pinouts back in the day, every manufacture had their own take on 
it to suit their own needs. For example, all the ROMs in a C64 have a 
nonstandard pinout. You could get EPROMs to match back in the day, but they 
were far less common. But Commodore was mass producing them in house so they 
did not care.

I am looking at a Sharp LH5367 ROM at this very moment from the PC-1500. It is 
very odd, it has a whole raft of chip selects/chip enables some of which are 
active high, some are active low. This was done to suit the application they 
were used in to reduce external decoding logic. 

The ROM inside the original M100 is just a Sharp made, Sharp pinout part. There 
was no need for them to make the option ROM socket an odd pinout just because 
they used this Sharp ROM inside. As I mentioned I think Kyocera figured this 
out fast and went to standard sockets and pinout in later models when they saw 
the uses the machines were put to. Nothing to do with Microsoft.

 

Jeff Birt

 

 

From: M100  On Behalf Of Stephen Adolph
Sent: Wednesday, May 19, 2021 7:45 AM
To: m...@bitchin100.com
Subject: Re: [M100] Other things that used the Molex socket

 

Tandy did release software using the strange socket. Multi-solutions for one, 
multiplan for another.The M100 main ROM also used the strange pinout. 

 

Didn't Microsoft supply the programmed M100 Main ROM PROMs to Tandy?   I think 
I read this somewhere, and in fact they released the PROMs with "Microsoft" all 
over the interface, against Tandy wishes.  Tandy was forced to release as is.

 

If this is true then I suspect Tandy had to implement the interface as per the 
agreement with Microsoft (which would have included pinout).

In later versions, they clearly got away from Microsoft 'shackles'.

 

In the end, I don't think Tandy 'chose' the pinout.  I think it was pushed on 
them by Bill.

 

 

On Wed, May 19, 2021 at 8:34 AM Jeffrey Birt mailto:bir...@soigeneris.com> > wrote:

You are absolutely correct about the cost of a masked ROM w.r.t. an EPROM or 
PROM. The option ROM socket was not intended for the main system firmware, it 
was for adding new functionality. Many times this added functionality was in 
the form of general productivity applications or sometimes it was specific to a 
particular company for insurance agents, or controlling laboratory equipment.

These aftermarket applications would never be released in sufficient quantity 
to justify a masked ROM and I’m not aware that Tandy ever released any software 
itself that way. However, both EPROMS and PROMs have been available since the 
mid-1970s and would have been the choice for these smaller scale software 
distributions so making the pin out match an industry standard 27C256 would 
have made more sense, IMHO. I think Kyocera figured this out fast though as all 
the subsequent machines ditched the funky option ROM socket and used a standard 
DIP socket with a standard pinout.

Jeff Birt

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Peter Noeth
Sent: Tuesday, May 18, 2021 7:30 PM
To: Model 100 Discussion mailto:m100@lists.bitchin100.com> >
Subject: Re: [M100] Other things that used the Molex socket

 

Jeff,

 

  You have to remember that the socket was designed for a "Masked ROM", like 
the Main ROM, which **was** the standard pinout. At that time there were no 
programable ROMs (PROMs or EPROMs) that had compatible pinouts, due to the 
circuit changes necessary for the programming function (capacitor "cells" in 
EPROMS and "fuses" in PROMS) that caused the pinout to change because of 
internal layout.

 

  Computer manufacturers used Masked ROMs to reduce the per chip cost in large 
quantities, where they didn't expect frequent changes in content. Also I don't 
remember a 32K EPROM being available in 1983. Most were 8K or less.

 

  The initial high cost of producing the "mask" and required minimum quantity 
order explains why there were not more "option ROMs" from other software 
houses. The One Time Programable (OTP) PROMs would have been a good choice, but 
didn't exist in the 32K size, and the OTP EPROMS didn't exist until decades 
later.

 

  I remember this was always a pain in modifying computer "operating systems"  
in the early days of "turn key" computers. Not a problem with the S-100 Bus 
systems, as the CPU board was loaded with easy to change EPROM sockets.

 

Regards,

 

Peter


--

Message: 2
Date: Tue, 18 May 2021 07:36:25 -0500
From: "Jeffrey Birt" mailto:bir...@soigeneris.com> >
To: mailto:m...@bitchin100.com> >
Subject: Re: [M100] Other things that used the Molex socket.
Message-ID: <019b01d74be2$6b1ffeb0$415ffc10$@soigeneris.com 
<http://soigeneris.com> >
Content-Type: text/plain;  

Re: [M100] Other things that used the Molex socket

[Jeffrey Birt]

You are absolutely correct about the cost of a masked ROM w.r.t. an EPROM or 
PROM. The option ROM socket was not intended for the main system firmware, it 
was for adding new functionality. Many times this added functionality was in 
the form of general productivity applications or sometimes it was specific to a 
particular company for insurance agents, or controlling laboratory equipment.

These aftermarket applications would never be released in sufficient quantity 
to justify a masked ROM and I’m not aware that Tandy ever released any software 
itself that way. However, both EPROMS and PROMs have been available since the 
mid-1970s and would have been the choice for these smaller scale software 
distributions so making the pin out match an industry standard 27C256 would 
have made more sense, IMHO. I think Kyocera figured this out fast though as all 
the subsequent machines ditched the funky option ROM socket and used a standard 
DIP socket with a standard pinout.

Jeff Birt

 

From: M100  On Behalf Of Peter Noeth
Sent: Tuesday, May 18, 2021 7:30 PM
To: Model 100 Discussion 
Subject: Re: [M100] Other things that used the Molex socket

 

Jeff,

 

  You have to remember that the socket was designed for a "Masked ROM", like 
the Main ROM, which **was** the standard pinout. At that time there were no 
programable ROMs (PROMs or EPROMs) that had compatible pinouts, due to the 
circuit changes necessary for the programming function (capacitor "cells" in 
EPROMS and "fuses" in PROMS) that caused the pinout to change because of 
internal layout.

 

  Computer manufacturers used Masked ROMs to reduce the per chip cost in large 
quantities, where they didn't expect frequent changes in content. Also I don't 
remember a 32K EPROM being available in 1983. Most were 8K or less.

 

  The initial high cost of producing the "mask" and required minimum quantity 
order explains why there were not more "option ROMs" from other software 
houses. The One Time Programable (OTP) PROMs would have been a good choice, but 
didn't exist in the 32K size, and the OTP EPROMS didn't exist until decades 
later.

 

  I remember this was always a pain in modifying computer "operating systems"  
in the early days of "turn key" computers. Not a problem with the S-100 Bus 
systems, as the CPU board was loaded with easy to change EPROM sockets.

 

Regards,

 

Peter


------

Message: 2
Date: Tue, 18 May 2021 07:36:25 -0500
From: "Jeffrey Birt" mailto:bir...@soigeneris.com> >
To: mailto:m...@bitchin100.com> >
Subject: Re: [M100] Other things that used the Molex socket.
Message-ID: <019b01d74be2$6b1ffeb0$415ffc10$@soigeneris.com 
<http://soigeneris.com> >
Content-Type: text/plain;   charset="UTF-8"

Interesting. I think if Kyocera/RadioShack had not chosen to go with the stupid 
non-standard pinout it would have been a more popular way of distributing 
custom applications for the machine. The socket itself was a good idea to make 
putting a chip in more idiot proof.

Jeff Birt

Re: [M100] Other things that used the Molex socket.

[Jeffrey Birt]

Interesting. I think if Kyocera/RadioShack had not chosen to go with the stupid 
non-standard pinout it would have been a more popular way of distributing 
custom applications for the machine. The socket itself was a good idea to make 
putting a chip in more idiot proof.

Jeff Birt

-Original Message-
From: M100  On Behalf Of Brian K. White
Sent: Monday, May 17, 2021 11:05 PM
To: M100 List 
Subject: [M100] Other things that used the Molex socket.

Just chanced across something else that used the Molex socket.

https://www.ebay.com/itm/124169271006

The bag says Intermec and KIT,EPROM,9440,64K.

There is a company called Intermec that has the same Everett, WA address as on 
that bag, and they have a device with a model number 9440.

I can't find any pictures of the back or inside, and the user manual doesn't 
show anything either.
https://cybarcode.com/sites/cy/files/manuals/intermec/9440_irl_manual.pdf

But this spec sheet does say "Optional 32 KB or 64 KB EPROM cartridge" 
in it:

https://cybarcode.com/sites/cy/files/specsheets/intermec/9440_specsheet.pdf

So besides Model 600 and Epson PX-4 and PX-8, that's one more thing that used 
that socket.

--
bkw

Re: [M100] SPAM-LOW: Model 100 Screen Fading to Black

[Jeffrey Birt]

You can take the knob off, one tiny phillips screw, and dribble some Deoxit 
where the shaft meets the top case (some will work its way inside). Then set 
knob on and rotate lock-to-lock 3-4 times and repeat. Give the Deoxit time to 
dry out and see if that fixed it. 

They are a odd pot and difficult to desolder, even if you can locate a spare.

 

Jeff Birt

 

From: M100  On Behalf Of Jason White
Sent: Sunday, May 16, 2021 8:24 PM
To: m100@lists.bitchin100.com
Subject: SPAM-LOW: [M100] Model 100 Screen Fading to Black

 

My Model 100 keeps giving me fits. The latest issue is that after a few minutes 
the screen will start getting darker and darker until it is completely black. 
It will flicker to the correct brightness if you wiggle the knob a bit, but it 
doesn’t stay, which I am guessing means it’s either dirty or just wore out. 

 

To date (before this problem started, but it had others...) I cleaned the board 
with alcohol and glycerin (thanks hey Birt!), replaced the nicad battery, 
removed said battery, removed rex rom, removed and reseated nonsoldered ram 
module, recapped logicboard, and walked away from it for a few weeks. 

 

If anyone has any suggestions, I’d love to hear them. 

 

J White

 

P.S.  I normally post on the Discord channel, but I haven’t gotten a message 
from the list in a while, so this is also a test to see if I am still on the 
list. :) 

Sent from Yahoo Mail for iPhone  

Re: [M100] Ordering a replacement NiCd for Model 100 - from where?

[Jeffrey Birt]

I carry them as does Arcadeshopper

 

https://www.soigeneris.com/memory-backup-battery-mbat1

 

Jeff Birt

 

From: M100  On Behalf Of Douglas Quagliana
Sent: Wednesday, May 12, 2021 9:40 AM
To: m...@bitchin100.com
Subject: [M100] Ordering a replacement NiCd for Model 100 - from where?

 

I have a Model 100 that wont boot consistently, or powers on to a screen with 
all the pixels on. When it does boot it usually crashes or freezes within a 
minute, but once or twice I have been able to get to BASIC and run a short 
program.  

 

I suspect the NiCd battery on the motherboard, which needs to be replaced on 
this unit anyway at this point.  Trying to (re)charge it overnight didn't work. 

 

>From what I can find, the part number is either 3-51FT or maybe 3-51FT-A ? 
>What's the difference? 

 

Does anyone on the mailing list sell them?  Where are people ordering their 
replacement NiCd battery from?

 

Regards,

Douglas

 

Re: [M100] Question on group etiquette

[Jeffrey Birt]

Hi Jerry! For me I think the image size limitation has been the biggest 
tripping point, just from me forgetting. It is understandable though. I set up 
a separate folder on my Onedrive for such things though so I can just provide a 
link to the image without dealing with on the image/spam sharing services.

 

Jeff Birt

 

From: M100  On Behalf Of Jerry Davis
Sent: Friday, May 7, 2021 1:22 AM
To: m...@bitchin100.com
Subject: [M100] Question on group etiquette

 

I'm a new member.  I joined after Jeff Birt and I did some troubleshooting on a 
broken M100 LCD display.  He recommended the group to me in an email.  I think. 
 Can't remember exactly how I got here but I had to have entered my email 
address in a form somewhere.  I'm not in the habit of doing that on a regular 
basis, but it has certainly been a lot of fun reading the messages posted on 
m100.

Re: [M100] NEC PC-8201(A) Recapping Help

[Jeffrey Birt]

The VEE level should be fine about 4.65V. As long as it does not change when 
you see the screen DIM. Since the LCD is fine in another computer that saves 
checking things on it.

 

You can try checking the voltage at pin 4 of the LCD connector. This is the 
contrast setting voltage after it does through a transistor.

 

Jeff Birt

 

From: M100  On Behalf Of ExPLIT | Pawel 
Radomychelski
Sent: Wednesday, May 5, 2021 5:00 PM
To: m...@bitchin100.com
Subject: Re: [M100] NEC PC-8201(A) Recapping Help

 

Did again some measuring:

 

Pin  Function   
  Measured   

3  VEE (-5V)
   -4,65V
4  VB   (Battery charge voltage) +4,98V

5  GND  
  
6  VDD (+5V)
 +5,00V

 

Can -4,65V instead -5V bea a Problem, Jeff ?

 

 

 

-- 

Kind regards / 

Mit freundlichen Grüßen

 

ExPLIT IT Solutions

Pawel Radomychelski

 

 

 

-Original Message-

From: ExPLIT | Pawel Radomychelski mailto:explit%20%7c%20pawel%20radomychelski%20%3cexp...@mailbox.org%3e> >

Reply-To: m...@bitchin100.com  

To: m...@bitchin100.com  

Subject: Re: [M100] NEC PC-8201(A) Recapping Help

Date: Wed, 05 May 2021 23:45:06 +0200

 

Thanks guys.

LCD unit is working fine on another NEC.

 

So maybe some chips.

Need to find a guru (who doesnt fear the word osciloscope)  here in Europe

 

 

Re: [M100] Bricked again

[Jeffrey Birt]

If it is not beeping, then it is not booting. The first thing I would check for 
is that both +5V and -5V are present.

 

Jeff Birt

 

 

From: M100  On Behalf Of Charles Hudson
Sent: Monday, May 3, 2021 5:57 AM
To: m100@lists.bitchin100.com
Subject: [M100] Bricked again

 

Nada.

 

-CH-

 


 

 

Virus-free.  

 www.avg.com 

 

Re: [M100] NEC PC-8201(A) Display issues

[Jeffrey Birt]

On the power supply connector counting from the left to right with the front of 
the machine toward you:

 

Pin  Function

3  VEE (-5V)
4  VB   (Battery charge voltage)

5  GND
6  VDD (+5V)

 

I have attached the relevant section of the schematic that deals with the 
contrast adjustment as well.

 

Jeff Birt

 

From: M100  On Behalf Of ExPLIT | Pawel 
Radomychelski
Sent: Sunday, May 2, 2021 11:38 AM
To: m...@bitchin100.com
Subject: Re: [M100] NEC PC-8201(A) Display issues

 

Thanks for the Info, Jeff.

 

Sorry for the dumb question, but can you point out on which two points i should 
measure +5V and -5V ?

I think this Info can be also very usefull for other folks having power issues 
on NEC.

 

Thanks

-- 

Kind regards / 

Mit freundlichen Grüßen

 

ExPLIT IT Solutions

Pawel Radomychelski

 

 

 

-Original Message-

From: Jeffrey Birt mailto:jeffrey%20birt%20%3cbir...@soigeneris.com%3e> >

Reply-To: m...@bitchin100.com <mailto:m...@bitchin100.com> 

To: m...@bitchin100.com <mailto:m...@bitchin100.com> 

Subject: Re: [M100] NEC PC-8201(A) Display issues

Date: Sun, 2 May 2021 11:34:12 -0500

 

OK. This sounds like a power supply issue. It is odd that it comes back to 
normal with a power cycle though. Take it apart so that you can measure the 
power supply voltages. Measure the +5 and -5V when it is working properly and 
then when the LCD goes blank.

 

Jeff Birt

 

-Original Message-

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of ExPLIT | Pawel 
Radomychelski

Sent: Sunday, May 2, 2021 10:53 AM

To: m...@bitchin100.com <mailto:m...@bitchin100.com> 

Subject: Re: [M100] NEC PC-8201(A) Display issues

 

No, this is not the case, i think.

Brightness is getting higher and higher until you don't see anything.

And this happens to different times: after 3, 5 or 10 minutes, sometimes after 
20.

On some units the lcd is flickering until it shut off.

 

Pressing a key doesn't activate the lcd back. Only full switch off / switch on.

 

On some units the contrast "jog dial" (doesn't know exact name of this part in 
English) doesnt work at all. Contrast is always locked to one position.

 

Kind regards

 

Pawel

 

 

On Sunday, 2 May 2021, Jeffrey Birt wrote:

The unit does have an auto power off if you have not used it for 5 minutes or 
so. Is this what you are experiencing?

 

 

 

Jeff Birt

 

 

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of ExPLIT | Pawel 
Radomychelski

Sent: Sunday, May 2, 2021 9:20 AM

To: m...@bitchin100.com <mailto:m...@bitchin100.com> 

Subject: [M100] NEC PC-8201(A) Display issues

 

 

 

Dear Model T / NEC collegues!

 

What i noticed holding a couple of NEC PC-8201 and PC-8201A in my hands, that 
many have a strange display issues:

 

 

 

Unit working fine, after some time display is getting blank and i can't see 
anything on the LCD.

 

After switch off/switch on - its fine again.

 

 

 

I noticed this problem independent prom Power Source (On AA Batteries and 6V DC 
Power Supply)

 

On some units this problem is getting better when replacing old NiCd Battery 
with a new one or with 1F / 5,5V Capacitor.

 

But still not solved completely.

 

 

 

This is a question on our gurus: Is there a chip (Or couple of chips and/or 
other components) on the mainboard which can / need to be replaced?

 

 

 

I am not so familiar with old electronics, nor i have an oscilograph.

 

Is it possible for an avarage user with moderate soldering skills and 
multimeter to solve such issues ?

 

 

 

Thanks!

 

-- 

 

Kind regards / 

 

Mit freundlichen Grüßen

 

 

 

ExPLIT IT Solutions

 

Pawel Radomychelski

 

 

 

 

 

 

 

 

 

Re: [M100] NEC PC-8201(A) Display issues

[Jeffrey Birt]

OK. This sounds like a power supply issue. It is odd that it comes back to 
normal with a power cycle though. Take it apart so that you can measure the 
power supply voltages. Measure the +5 and -5V when it is working properly and 
then when the LCD goes blank.

Jeff Birt

-Original Message-
From: M100  On Behalf Of ExPLIT | Pawel 
Radomychelski
Sent: Sunday, May 2, 2021 10:53 AM
To: m...@bitchin100.com
Subject: Re: [M100] NEC PC-8201(A) Display issues

No, this is not the case, i think.
Brightness is getting higher and higher until you don't see anything.
And this happens to different times: after 3, 5 or 10 minutes, sometimes after 
20.
On some units the lcd is flickering until it shut off.

Pressing a key doesn't activate the lcd back. Only full switch off / switch on.

On some units the contrast "jog dial" (doesn't know exact name of this part in 
English) doesnt work at all. Contrast is always locked to one position.

Kind regards

Pawel


On Sunday, 2 May 2021, Jeffrey Birt wrote:
> The unit does have an auto power off if you have not used it for 5 minutes or 
> so. Is this what you are experiencing?
> 
>  
> 
> Jeff Birt
> 
>  
> 
> From: M100  On Behalf Of ExPLIT | Pawel 
> Radomychelski
> Sent: Sunday, May 2, 2021 9:20 AM
> To: m...@bitchin100.com
> Subject: [M100] NEC PC-8201(A) Display issues
> 
>  
> 
> Dear Model T / NEC collegues!
> 
> What i noticed holding a couple of NEC PC-8201 and PC-8201A in my hands, that 
> many have a strange display issues:
> 
>  
> 
> Unit working fine, after some time display is getting blank and i can't see 
> anything on the LCD.
> 
> After switch off/switch on - its fine again.
> 
>  
> 
> I noticed this problem independent prom Power Source (On AA Batteries and 6V 
> DC Power Supply)
> 
> On some units this problem is getting better when replacing old NiCd Battery 
> with a new one or with 1F / 5,5V Capacitor.
> 
> But still not solved completely.
> 
>  
> 
> This is a question on our gurus: Is there a chip (Or couple of chips and/or 
> other components) on the mainboard which can / need to be replaced?
> 
>  
> 
> I am not so familiar with old electronics, nor i have an oscilograph.
> 
> Is it possible for an avarage user with moderate soldering skills and 
> multimeter to solve such issues ?
> 
>  
> 
> Thanks!
> 
> -- 
> 
> Kind regards / 
> 
> Mit freundlichen Grüßen
> 
>  
> 
> ExPLIT IT Solutions
> 
> Pawel Radomychelski
> 
>  
> 
>  
> 
>  
> 
>

-- 
Kind regards / Mit freundlichen Grüßen

ExPLIT IT Soltions
Pawel Radomychelski

Re: [M100] NEC PC-8201(A) Display issues

[Jeffrey Birt]

The unit does have an auto power off if you have not used it for 5 minutes or 
so. Is this what you are experiencing?

 

Jeff Birt

 

From: M100  On Behalf Of ExPLIT | Pawel 
Radomychelski
Sent: Sunday, May 2, 2021 9:20 AM
To: m...@bitchin100.com
Subject: [M100] NEC PC-8201(A) Display issues

 

Dear Model T / NEC collegues!

What i noticed holding a couple of NEC PC-8201 and PC-8201A in my hands, that 
many have a strange display issues:

 

Unit working fine, after some time display is getting blank and i can't see 
anything on the LCD.

After switch off/switch on - its fine again.

 

I noticed this problem independent prom Power Source (On AA Batteries and 6V DC 
Power Supply)

On some units this problem is getting better when replacing old NiCd Battery 
with a new one or with 1F / 5,5V Capacitor.

But still not solved completely.

 

This is a question on our gurus: Is there a chip (Or couple of chips and/or 
other components) on the mainboard which can / need to be replaced?

 

I am not so familiar with old electronics, nor i have an oscilograph.

Is it possible for an avarage user with moderate soldering skills and 
multimeter to solve such issues ?

 

Thanks!

-- 

Kind regards / 

Mit freundlichen Grüßen

 

ExPLIT IT Solutions

Pawel Radomychelski

 

 

 

Re: [M100] Memory release question

[Jeffrey Birt]

>>Another objective is to develop a reliable method for tape duplication before 
>>I damage or wear out the OEM distributions.  I am thinking it might be 
>>possible to make a digital copy of the OEM tape on my Win10 machine, using a 
>>hi-fi tape deck as the playback source and Audacity as the DTR.  With luck 
>>reversing the roles will yield a functional copy tape.  But again, if someone 
>>has a better idea...

 

Ironically a HiFi deck might be the best tape desk to use. I can recall reading 
a few years ago that when computer program cassettes are duplicated using HiFi 
decks the results are often poor as these units are capable of picking up and 
reproducing a lot of the unintentional harmonics in the original recording. 
Whereas a good quality deck would do a good job at duplication.

Also, a HiFi desk is likely to be stereo but the vast majority of computer 
cassettes are mono. The only exception I know of is Atari who used the second 
track for audio recordings. 

I’m kind of in the opposite bind trying to fix a few Convergant Workslates I 
have. They have a built in microcassette which uses a stereo head. I suspect 
that one track may have been for audio recordings (as you could also use the 
computer to dictate audio note to accompany a program) but then you could also 
use it as a telephone answering machine (strange idea). Without access to a 
stereo microcassette deck, of which only a few HiFi decks seems to have been 
made, I’m stuck as both cassette decks I have are not working.

 

Jeff Birt

 

From: M100  On Behalf Of Charles Hudson
Sent: Friday, April 30, 2021 12:37 PM
To: m100@lists.bitchin100.com
Subject: [M100] Memory release question

 

Thanks, Peter, for your explanation of the memory segmentation issue; the fact 
that there is no 80C85 Jump Relative opcode and thus no relocation was unknown 
to me.  As you may deduce my depth on the M100 is pretty shallow.  Until 
recently I had only the bar code reader software to play with (other than the 
ROM suite) and my bar code reader seems to be DOA, so not much familiarity with 
machine code.

Re: [M100] T102 Current Drain

[Jeffrey Birt]

The only way I can see the memory battery making any real difference in the AA 
battery life is if you use the machine so infrequently that the battery is 
allowed to go flat. Then when you put a new set of AA batteries in they will 
have to charge the memory battery up completely. 

 

Jeff Birt

 

From: M100  On Behalf Of Alex ...
Sent: Wednesday, April 28, 2021 3:27 AM
To: m...@bitchin100.com
Subject: Re: [M100] T102 Current Drain

 

I don't have any real measurements to back this up, but someone might find this 
anecdote useful. 

 

I feel like my 102's AA battery life was much better after I cut out the 
internal NiCd cell. This idea is supported by the fact that it again seems to 
go through batteries faster since I replaced the backup battery with a new one.

 

Worth noting I run the machine on Eneloop NiMH cells, not alkalines.

 

On Tue, Apr 27, 2021, 20:51 Peter Noeth mailto:petern0...@gmail.com> > wrote:

I know this has been discussed before, but I was doing some testing on my T102 
regarding current drain to gauge external battery life. I made an external 4D 
cell alkaline pack I use when watching TV and playing with the computer a few 
years ago, and was thinking of upgrading the capacity. There is no convenient 
A.C. outlet near by to my viewing position, hence the battery pack.

 

I measured this on a 32K Tandy 102 w/REX installed.

*   0.4mA - Computer off, no peripherals connected
*   66.5mA - Computer on running a BASIC program, no peripherals connected
*   67.2mA - Computer running a BASIC program and printing to my DPU-414 
thermal printer
*   71.8mA - Computer running REXMGR, no peripherals connected
*   114.7mA - Computer running a BASIC program, printer connected but 
powered OFF
*   130mA - Computer running a BASIC program with Unitek Barcode Wand 
connected

I am sure a M100 would give similar results, but maybe a little higher in some 
cases, due to the T102 being mostly surface mount components and the circuitry 
optimized somewhat over the M100

 

The surprise was the marked current increase with the printer connected, but 
powered OFF. There is obviously some sneak current paths if the printer is not 
ON. Likely in the printers Centronics interface chip. This is good to know if 
trying to maximize battery life.

 

The current draw increase with the Unitek Barcode Wand connected was expected, 
due to the fact that it has a very bright red LED, that is on all the time. The 
RS Barcode wand likely draws less when its button is pressed to turn on the dim 
LED. I like the Unitek wand better, as it reads codes that are not black on a 
white background, like on food cans and potato chip bags. Radio Shack just 
private labeled the HP wand for the 41-C calculator, which was low power and 
expecting white paper barcode labels and program listings.

 

Regards,

 

Peter

Re: [M100] Happy Earth Day from my M100

[Jeffrey Birt]

It will not get thrown away at the very least it will provide parts to fix 
other machines 


Jeff

-Original Message-
From: M100  On Behalf Of Robert J. Hutchins
Sent: Monday, April 26, 2021 8:19 PM
To: m...@bitchin100.com
Subject: Re: [M100] Happy Earth Day from my M100

Well, I hope you can fix that M102 board, would be shame to throw it away.
However I did overheat that socket...

-Original Message-
From: M100 [mailto:m100-boun...@lists.bitchin100.com] On Behalf Of Jeffrey Birt
Sent: Monday, April 26, 2021 6:09 PM
To: m...@bitchin100.com
Subject: Re: [M100] Happy Earth Day from my M100

>>And that M102 board I donated, do you think you will be able  fix it? Just 
>>curious I also have the empty case and keyboard but no LCD if you or anyone 
>>wants it.

I have a 102 with a bad LCD glass and other unknown problems. I was recently 
able to get a few M100 LCDs, and the glass is the same. I may try to swap one 
of the M100 LCD glasses into the 102 LCD frame/PCB and then use parts from both 
PCBs to make one good 102.

I had the LCD frame on the 102 apart several times fixing a bad trace and 
diagnosing the fault was in the glass itself so it may or may not last one more 
round. It would be fun to takes parts of three machines and make on good one 
though.

Jeff

-Original Message-
From: M100  On Behalf Of Robert J. Hutchins
Sent: Monday, April 26, 2021 7:17 PM
To: m...@bitchin100.com
Subject: Re: [M100] Happy Earth Day from my M100

Jeff,

Sorry about that.
And that M102 board I donated, do you think you will be able  fix it? Just 
curious I also have the empty case and keyboard but no LCD if you or anyone 
wants it.

-Original Message-

Re: [M100] Happy Earth Day from my M100

[Jeffrey Birt]

>>And that M102 board I donated, do you think you will be able  fix it? Just 
>>curious I also have the empty case and keyboard but no LCD if you or anyone 
>>wants it.

I have a 102 with a bad LCD glass and other unknown problems. I was recently 
able to get a few M100 LCDs, and the glass is the same. I may try to swap one 
of the M100 LCD glasses into the 102 LCD frame/PCB and then use parts from both 
PCBs to make one good 102.

I had the LCD frame on the 102 apart several times fixing a bad trace and 
diagnosing the fault was in the glass itself so it may or may not last one more 
round. It would be fun to takes parts of three machines and make on good one 
though.

Jeff

-Original Message-
From: M100  On Behalf Of Robert J. Hutchins
Sent: Monday, April 26, 2021 7:17 PM
To: m...@bitchin100.com
Subject: Re: [M100] Happy Earth Day from my M100

Jeff,

Sorry about that.
And that M102 board I donated, do you think you will be able  fix it? Just 
curious I also have the empty case and keyboard but no LCD if you or anyone 
wants it.

-Original Message-

Re: [M100] Happy Earth Day from my M100

[Jeffrey Birt]

Give it a rest, please...

Jeff Birt

-Original Message-
From: M100  On Behalf Of Robert J. Hutchins
Sent: Monday, April 26, 2021 6:56 PM
To: m...@bitchin100.com
Subject: Re: [M100] Happy Earth Day from my M100

"It is the left who have promoted the nonsense that the Earth is in danger"
That sounds like an insult to me.
Sorry if I offended anyone.
I forget that there are kinds of people on this board, maybe some flat earthers 
too!
Enough said, I will leave it there.

-Original Message-
From: M100 [mailto:m100-boun...@lists.bitchin100.com] On Behalf Of Robert J. 
Hutchins
Sent: Monday, April 26, 2021 2:49 PM
To: m...@bitchin100.com
Subject: Re: [M100] Happy Earth Day from my M100

I think if you are unable to behave, you should leave this board. Please keep 
the politics out of this space.
There are plenty of places on the Internet where you can discuss your ignorant 
beliefs. 
This is not the place.

-Original Message-
From: M100 [mailto:m100-boun...@lists.bitchin100.com] On Behalf Of Hiraghm
Sent: Monday, April 26, 2021 10:41 AM
To: m100@lists.bitchin100.com
Subject: Re: [M100] Happy Earth Day from my M100

No, it's a leftist cause. It is the left who have promoted the nonsense that 
the Earth is in danger... from Man. Specifically, from western civilization. 
For political purposes.

Oh, and Soylent Green ISN'T a thing, either.

(I originally typed this on my Model 100, then copied it into my Windows email 
client by reading the M100's screen and typing it into the Windows computer. So 
it's on-topic and relevant)

Message: 9
Date: Sat, 24 Apr 2021 22:17:08 -0700
From: Peter Vollan To:m...@bitchin100.com
Subject: Re: [M100] Happy Earth Day from my M100
Message-ID:

Content-Type: text/plain; charset="utf-8"

"saving the Earth" is a liberal cause. Hey, wait a minute.

Re: [M100] Happy Earth Day from my M100

[Jeffrey Birt]

>> There are plenty of places on the Internet where you can discuss your 
>> ignorant beliefs. 
This is not the place.

Nor is this a place for personal insults...

Jeff Birt

-Original Message-
From: M100  On Behalf Of Robert J. Hutchins
Sent: Monday, April 26, 2021 4:49 PM
To: m...@bitchin100.com
Subject: Re: [M100] Happy Earth Day from my M100

I think if you are unable to behave, you should leave this board. Please keep 
the politics out of this space.
There are plenty of places on the Internet where you can discuss your ignorant 
beliefs. 
This is not the place.

Re: [M100] Assembler question

[Jeffrey Birt]

Yes, TASM is still available. The shareware version is included in the GitHub 
repo I posted. I was also recently able to contact the author and register to 
get the source. 

With the source I was able to create a new assembly argument rule to more 
easily support the Sharp lh5801 processor’s odd branching (separate fwd and 
back opcodes so can branch +- 255).

I’ll update GitHub with the latest shareware version on in the near future, for 
use with the 8085 the current version works just fine.

 

Jeff Birt

 

 

From: M100  On Behalf Of John R. Hogerhuis
Sent: Sunday, April 25, 2021 2:16 PM
To: m...@bitchin100.com
Subject: Re: [M100] Assembler question

 

Is Telemark Assembler itself still available? It's definitely a good one, I 
used it for HTERM. 

 

There's also as assembler which fully supports the 8085. I've used that 
too. You probably want to use it with a separate preprocessor.

 

http://shop-pdp.net/ashtml/

 

There are others. 

 

And all of these will benefit from usage with a make system. 

 

-- John.  

 

 

Re: [M100] Assembler question

[Jeffrey Birt]

A popular assembler from back in the day is TASM. It supports many different 
processors including the 8085. I did a VS Code extension for it a few months 
ago. The link to the GitHub repo and the video I did about it is below. There 
is also a PDF in the repo to help get you started.

GitHub repo: https://github.com/Jeff-Birt/TASM_vsCode_Extension
Video: https://youtu.be/kamDP5FA6Bg

Jeff Birt

 

From: M100  On Behalf Of Douglas Quagliana
Sent: Sunday, April 25, 2021 1:31 PM
To: m...@bitchin100.com
Cc: Model 100 Discussion 
Subject: Re: [M100] Assembler question

 

By coincidence, I'm also looking for a good assembler for the M100/200.  Got a 
suggestion?

 

I found the book 8080 8085 Software Design (Sams, 1978) by Christopher Titus, 
Peter Rony, David Larsen and Jonathan Titus

is available at 

 

https://archive.org/details/80808085SoftwareDesign 

 

and the TEA book that I found is actually in Spanish(?) at

 

https://archive.org/details/teauneditorassemblerresidenteper80808085/mode/1up

 

I suppose the latter book has the same assembler listing for the TEA software 
even though

the text is not in English.  I didn't find the actual TEA software binaries 
anywhere.

 

Douglas

 

 

Re: [M100] Dead Keyboard

[Jeffrey Birt]

Does the RTC drive an interrupt to service the KB? Interesting I did not 
realize that.

 

Jeff Birt

 

From: M100  On Behalf Of Stephen Adolph
Sent: Friday, April 23, 2021 4:56 PM
To: m...@bitchin100.com
Subject: Re: [M100] Dead Keyboard

 

I suspect that there is a problem with the internal real time clock.

I would check if there is a pulse on pin 10.   Hard to verify that I will admit.

 

Basically, pin 10 is the timer pulse on the RST7.5 input to the processor.  If 
you have a problem here your keyboard service routine will be "dead".

 

To me it sounds a bit like a dead x1 crystal at pin 12/13 of the real time 
clock chil.

 

On Fri, Apr 23, 2021 at 5:40 PM John R. Hogerhuis mailto:jho...@pobox.com> > wrote:

 

 

On Fri, Apr 23, 2021 at 1:44 PM Matthew Walworth mailto:mwalwo...@icloud.com> > wrote:

Thank you for pointing me at that document, John. No luck with the procedure 
fixing the unresponsive keyboard, although it did bring to my attention that 
there is a slight glitch in the upper left corner of the LCD. When first turned 
on, where it should show "Jan" it shows three other characters. After being on 
for a few seconds the "Jan" display appears. I also just realized that the 
clock doesn't start counting up after the reset. It should shouldn't it? 

 

Yes. After a hard reset it should start up in Jan almost immediately (I think 
seconds later is significant problem), and the clock should start counting up.

-- John.

Re: [M100] M100 case colour...

[Jeffrey Birt]

I would also guess there is not one single correct color but a small range. 
Typically, the raw plastic used will be produced by different companies at 
different times to a specification. There will be variations even lot to lot 
from the same manufacturer. 

 

Jeff Birt

 

 

From: M100  On Behalf Of 
jonathan.y...@telia.com
Sent: Wednesday, April 21, 2021 12:14 PM
To: m...@bitchin100.com
Subject: Re: [M100] M100 case colour...

 

Probably one could open one up, sand the plastic (on the inside) to reveal the 
original colour, and then take it to a paint store that can read colors.  They 
need a big enough spot to measure, but then you can get an NCS code that should 
match.  We've done that with paint samples for our house, and even played 
around with some 'classic' colours done with linseed oil paint and classic 
pigments.  Once we had what we wanted with the traditional paint, we took it in 
and had modern latex-based paint mixed up to match.  So it is possible, just 
someone has to do the legwork, but I guess that is the question asked by the 
original post.

 

I've heard it is done with cars being painted too.

 

Jonathan

Ursprungligt meddelande
Från : jesslafl...@gmail.com  
Datum : 2021-04-21 - 18:44 (CEST)
Till : m...@bitchin100.com  
Ämne : Re: [M100] M100 case colour...

I think it's still possible.  

Both of my M100s are very "pale" and seem to match the photos in the magazines 
I have rather well! 

In addition, this knowledge may have been known, just like the Apple II was 
determined without resorting to colour analysis of 40 year old paint. 

Was just hoping someone here may already know, inside info or the like. 

 

Ultimately, if I don't get a satisfactory answer, I'll do an analysis myself 
and try to compensate for bromine yellowing... 

 

On Wed, Apr 21, 2021 at 12:01 PM Micah Cowan < mi...@addictivecode.org 
mailto:mi...@addictivecode.org');return%20false;> > 
wrote: 

Is it even possible to know that at this point? 

The Apple II is painted metal... the M100 is an unpainted plastic whose shade 
darkens/yellows over time. Even if you were to color match the original, it 
wouldn't color match with anyone's M100 today, I'd think. 

 

-mjc 

 

On Tue, Apr 20, 2021 at 2:17 PM Jesse Lafleur < jesslafl...@gmail.com 
mailto:jesslafl...@gmail.com');return%20false;> > 
wrote: 

Anyone have any idea the colour of the M100? 

Apple II colour has been well established and figured out, but I am wondering 
if anyone has done the detective work to determine a modern match for the M100? 

 

-Jesse 

 

 

Re: [M100] Dead Keyboard

[Jeffrey Birt]

It is odd that you only seem to get a response form the CTRL and BRK keys.
Although looking at the schematic just now I realize that the keys Brake,
caps, num, code, grph, ctrl and shift are all strobed by PBO all other keys
are strobed by PA0-7. Ports PA and PB both come from the 8155. Both ports
are also used by the LCD so if the LCD is working then PA is working.


Just for giggles you might turn off the memory battery switch, let it set 10
minutes and then turn it back on. This should clear all the RAM. Then turn
it back on and try a hard reset again.

Jeff Birt

-Original Message-
From: M100  On Behalf Of Matthew Walworth
Sent: Monday, April 19, 2021 8:55 PM
To: m100@lists.bitchin100.com
Subject: [M100] Dead Keyboard

Hello All,

I dragged my T102 out of the closet a few days ago. It fired right up, but
the keyboard seems to be dead. It was working fine when I had it out last
about 4 or 5 years ago and in fact appeared to have a couple of files left
on it that I had been playing with. I opened it up expecting to maybe find
that the backup battery had leaked but everything inside looks very clean. I
put some batteries in and let it sit overnight plugged in but still no go. I
tried a cold restart and that worked which leads me to believe that the
keyboard must be being read to some extent since it detected that the ctrl
and pause keys were pressed.

Does anybody have any suggestions as to what I should do next as far as
diagnosing the problem? I have a multimeter but no scope or logic probe. Any
suggestions are appreciated.

...matthew...

Re: [M100] anyone in San Francisco Bay Area?

[Jeffrey Birt]

If you don’t find a local buyer I would be interested. If you can pack it up 
safe I can provide the shipping label.

 

Jeff Birt

 

From: M100  On Behalf Of John R. Burns
Sent: Monday, April 19, 2021 5:47 PM
To: m...@bitchin100.com
Subject: [M100] anyone in San Francisco Bay Area?

 

I have a M100 32K, case, and manuals that need a new home. 

 

Needs work ... LCD is intermittent and left Shift key doesn't work. Might be 
good for parts. 

 

Might be expensive to ship ... hoping to find someone local to San Fransisco 
Bay Area. 

 

Thanks,

John Burns




Sent from the all new AOL app for iOS 
 

Re: [M100] NEC PC-8201A 3,6V Barrel Battery Replacement

[Jeffrey Birt]

I have them and Arcadeshopper does too: 
https://www.soigeneris.com/memory-backup-battery-mbat1

 

Jeff Birt

 

From: M100  On Behalf Of ExPLIT | Pawel 
Radomychelski
Sent: Saturday, April 17, 2021 5:33 PM
To: m...@bitchin100.com
Subject: Re: [M100] NEC PC-8201A 3,6V Barrel Battery Replacement

 

Thanks for the Info, Josh,

 

will go back to NiMH, but V15H, which i found on eBay have only 20 mAh, where 
the original had 50 mAh.

Is it critical?

Should i look for 50 mAh and more?

 

Thanks

 

-- 

Kind regards / 

Mit freundlichen Grüßen

 

ExPLIT IT Solutions

Pawel Radomychelski

 

 

 

-Original Message-

From: Josh Malone mailto:josh%20malone%20%3cjosh.mal...@gmail.com%3e> >

Reply-To: m...@bitchin100.com  

To: m...@bitchin100.com  

Subject: Re: [M100] NEC PC-8201A 3,6V Barrel Battery Replacement

Date: Sat, 17 Apr 2021 18:19:11 -0400

 

The battery rail in the M100 can rise almost up to the 5v rail

sometimes (unless I'm mistaken), but even the 3.6v rating of NiMH is

above what LiMnO2 wants (3.3) so I would strongly recommend going back

to NiMh.

 

https://biz.maxell.com/en/rechargeable_batteries/ML_17e.pdf

 

-Josh

 

On Sat, Apr 17, 2021 at 4:58 PM ExPLIT | Pawel Radomychelski

mailto:exp...@mailbox.org> > wrote:

 

Good evening collegues!

 

Today i replaced the barrel Battery (Yuasa  3-51FT-A, 3,6V 50mAh)  in my NEC 
PC-8201A with a rechargable button cell (Maxell ML2032 3V 65mAh)

 

Now i ask me, if this mod is kosher, or should i choose another NiMh Barrel 
Battery with 3,6V ?

 

Thanks

 

 

--

 

Kind regards /

Mit freundlichen Grüßen

 

ExPLIT IT Solutions

Pawel Radomychelski

 

 

Re: [M100] NEC PC-8201 adjusting contrast doesnt work

[Jeffrey Birt]

Measure the -5V supply rail. It could be low because the RS232 level shifter 
chip has faults. Also check the +5V and -5V at the LCD itself to rule out a 
connection issue (bad joint at connector or leading to connector).

Jeff Birt

-Original Message-
From: M100  On Behalf Of ExPLIT | Pawel 
Radomychelski
Sent: Friday, April 16, 2021 2:20 PM
To: m100@lists.bitchin100.com
Subject: [M100] NEC PC-8201 adjusting contrast doesnt work

Hello collegues.
I got an Japanese NEC PC-8201.
While its working, i can't adjust lcd contrast.

I tried already change lcd and power board, but it didnt help.
Problem is somewhere on the mainboard.
I removed the round black part for ajusting lcd contrast, cleaned it and put 
back on.
Didn't help.
Sometimes i see also small flimmering, lcd is getting a bit darker and than 
back to normal.

Did somebody had the same issue?

Thanks

-- 
Kind regards / Mit freundlichen Grüßen

ExPLIT IT Soltions
Pawel Radomychelski

Re: [M100] Need help fixing VEE on M100

[Jeffrey Birt]

I bought a jar of this more than a year ago and have found it works very well. 
I prefer paste flux to the 'no clean' type as the fumes are far less 
irritating. 

https://www.jameco.com/z/RSF-R80-2-Caig-Labs-Deoxit-DeoxIT-Rosin-Flux-Soldering-Paste-56-Gram-Jar_2094258.html

Jeff

-Original Message-
From: M100  On Behalf Of Eric LK
Sent: Wednesday, April 14, 2021 8:36 AM
To: m100@lists.bitchin100.com
Subject: Re: [M100] Need help fixing VEE on M100

"Jeffrey Birt"  wrote:
> Welcome to the fun world of leaking electrolytic capacitors. Trace 
> damage like this is very common and if someone replaces the capacitors 
> without properly mitigating the damage the corrosion will continue to 
> spread and get worse. 'Half-way' repairs cause as many problems as the 
> original failures.

Thanks for confirming what I was afraid of :o)

Well, I guess I'll just have to do this then. I have everything except the 
paste flux and nail polish, but that should be easy to find.

Thanks again for the very detailed instructions!

Eric

Re: [M100] M100 DVI cover panel

[Jeffrey Birt]

>>Good question. The STL file is somehow scaled wrong or drawn in units of feet 
>>or even yards or something. Even when I load it in FreeCAD with the units set 
>>to inches, the part comes out with dimensions like 0.1205 inches on the 
>>longest side, which is ridiculous.

There are some 'interesting' modeling programs out there that do a very odd job 
at exporting STL files. I see this time to time with a STL file a student sends 
me. Since a STL file contains no scaling or units data there is no way to tell 
how it was exported. A month or so ago a student sent me a file and after some 
email exchanges they figured out I needed to scale it by 3.7 or something 
stupid to get it to come out the correct size.

Jeff Birt

Re: [M100] Need help fixing VEE on M100

[Jeffrey Birt]

Welcome to the fun world of leaking electrolytic capacitors. Trace damage like 
this is very common and if someone replaces the capacitors without properly 
mitigating the damage the corrosion will continue to spread and get worse. 
'Half-way' repairs cause as many problems as the original failures.

Cleaning with the fiberglass pen to get the loose/flakey stuff off and down to 
bare copper is essential. The electrolyte is acidic so you can use a mild 
alkaline solution to neutralize it, something like baking soda and water, or 
Formula 409 (any alkaline home cleaning product would probably work). Let that 
set on the corrosion for an hour or so and then wipe off and flush with 
alcohol. Once the alcohol is dry apply paste flux and tin up all the bare 
copper. This will not only help protect the copper it will also bring up more 
contamination. Then clean again with alcohol. 

This is a good time to ohm out all your traces and plan how to do any trace 
repair. Once that is done, or done as much as you can before reinstalling the 
caps coat the al; the tined areas, except where you will solder, with a PCB 
topcoat or nail polish. Let that dry and then install your caps and add any 
needed bodge wires. 

This is not hard work but it sure is time consuming.

Jeff Birt

-Original Message-
From: M100  On Behalf Of Eric LK
Sent: Sunday, April 11, 2021 7:17 AM
To: m100@lists.bitchin100.com
Subject: Re: [M100] Need help fixing VEE on M100

Le lun. 22 mars 2021 à 19:05, Eric LK  a écrit :
>
> I didn't recapped this unit because the seller I purchased it from 
> told me he did it a couple of years ago, but I think I'll just follow 
> your advice on this (also, I'm not sure he did clean the flux).
>
> I already have the caps so I guess I know what I'll do next week-end 
> :o)

I eventually freed some time to look into recapping this unit, but I kind of 
stop in the middle to ask for some advice:

Looking at the PCB, I could confirm that the unit has been recapped recently as 
the previous owner said, so I tried to first change only the caps near the 
power supply (C82, C83, C84 C85, C86, C90 and C92).
I tested all of them, and they appear to be in specs, so I had a good look at 
the PCB under the caps I removed, and I think that may be the problem...

I put some pictures on http://pics.lefauve.org/Recap2021/  (that were taken 
after using IPA, an "electronic cleaning solvent", more IPA and a glass fiber 
pen; it was looking worse before...).

I'm a little concerned about some of the caps pads and their connecting traces 
like C82, C85 and C86. I've never come across this kind of damage before and 
I'm not sure how to continue.

My first thought would be to replace the caps, and to use the schematics to 
check the continuity between each of those cap legs and whatever they're 
supposed to be connected to, bridging any non-conductive trace with some wire 
but I could really use any advice you have before risking to make everything 
worse :o)

Eric.

Re: [M100] TPDD alignment disk / servicing / MICTDC

[Jeffrey Birt]

Most ‘real’ alignment disks are written on special drives that are not only 
very, very precisely calibrated but they can also vary the angle of the head. 
This angled write somehow enhances the ability to detect alignment issues with 
the use of an oscilloscope monitoring the head output (don’t remember the exact 
reasoning off the top of my head.)

 

At some point I found a blog where someone described aligning a TPDD by 
adjusting the position of the home sensor. He just small very small changes 
tried to read a disk, made another small change, etc.

 

On the C64 drives I use commercially produced disks, which are made on fancy 
duplication machines that were kept well aligned. There is C64 software which 
can tell you how close the alignment is (it microsteps the head as I recall so 
it can find at which microstepped position the signal is highest by less 
garbled data I would guess). This works well and can get you close enough for 
the drive to work very reliably.

On the TPDD it might also help to use a commercially produced disk as there is 
a much better chance it was written on a duplication machine that was more 
precise. As original disks seem to be as rare as hen’s teeth these days you 
might be stuck with trying to read a variety of disks written on other TDPPs.

 

Jeff Birt

 

From: M100  On Behalf Of Stephen Adolph
Sent: Saturday, April 3, 2021 7:00 AM
To: m...@bitchin100.com
Subject: [M100] TPDD alignment disk / servicing / MICTDC

 

Now that we have the official service manual for TPDD, I am wondering if anyone 
knows something about the alignment disk.

 

It seems like the alignment disk is needed to adjust the track position.

Can we use a "stock disk" for this as well?  Maybe the alignment disk is an 
idealized signal with a golden alignment, but seems like a factory disk might 
do as well.

 

The document also mentions MICTDC program which was provided on a tape 
AXX-2049.  Anyone have that cassette or program?

 

..Steve

Re: [M100] Does anyone actually use MFORTH?

[Jeffrey Birt]

The word .S prints out what is on the stack at that time without disturbing it. 
It will never show you more or less than what is on the stack. If what is on 
the stack does not make sense it is because of an error in programming and this 
is very, very easy to do. 

 

One of the most helpful things for me was to write out each line of code (each 
Word) on a different line and add a comment to the left as to what the stack 
contents would be afterwards. While this is time consuming it has the benefit 
of making it clear what is happening to the stack after each step. 

 

One of the best parts of Forth is that it encourages you to create small 
modules which are easier to debug. If you create a new word that is supposed to 
take two values off the stack and manipulate them and return the result you can 
check the functionality by clearing the stack, typing in two test values and 
then executing your new Word. Then to a .S to check the result. Remember though 
that .S leave the stack contents there so if you want to run another such test 
you would want to clear the stack first.

 

Jeff Birt

 

From: M100  On Behalf Of Alex ...
Sent: Monday, March 29, 2021 1:25 PM
To: m...@bitchin100.com
Subject: Re: [M100] Does anyone actually use MFORTH?

 

Cool, so newbie mistakes and ignorance. As long as my computer's working 
properly. :) 

 

What threw me off is in the book, (pg.25) it talks about returning usually 0 
and printing STACK EMPTY, which is definitely not how the machine behaved when 
trying it.

 

I don't expect everything to have bounds checking, but I'm using .S a lot to 
inspect the stack, so having to reset the machine all the time and start over 
kind of sucks. If I knew more about the system maybe I could rewrite .S to know 
if it's looking at the stack or what's underneath?

 

About the editor: I skipped over the whole chapter on the arcane line editor 
and page/block-based disk storage since this machine has none of that. Using 
TEXT with .DO files works ok, as long as whatever I'm doing doesn't trample the 
files in RAM.

 

Thanks for the tutorial videos, Birt. They've been helpful! If I had a C=64 
kicking around here I would definitely give DurexForth a try.



On Mon, Mar 29, 2021, 08:37 Jeffrey Birt mailto:bir...@soigeneris.com> > wrote:

This is the default behavior for most all vintage 8-bit Forth implementations. 
To do a bounds check might take 6-10 machine cycles for every word. This does 
not seem like a lot, but it would have a noticeable impact on performance. 

 

When I ventured Forth a few years ago I found that Forth Inc has a PC based 
Forth Dev system that is pretty forgiving and a good way to learn without 
crashing a machine. https://www.forth.com/ . There is also a good online Forth 
tutorial with a web based Forth implementation: 
https://skilldrick.github.io/easyforth/ 

 

I got the most out of DurexForth which is a modern Forth implementation on the 
C64. You still get the vintage goodness but with a good VI like editor and 
actual file support rather than the super goofy and crude typical Forth screens 
and blocks. I did a few cheesy Forth videos at the time too: 
https://www.youtube.com/watch?v=TXIDqptXmiM (lots of links in the description).

 

Jeff Birt

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Alex ...
Sent: Sunday, March 28, 2021 9:39 PM
To: Model 100 Discussion mailto:m100@lists.bitchin100.com> >
Subject: [M100] Does anyone actually use MFORTH?

 

Hello Tandy laptop nerds,

So I've been reading Leo Brodie's "Starting Forth" and using my '102 as a 
playground / labrat. There's been a few inconsistencies I expected and can live 
with/work around, but I've noticed what seems like really bad bugs. It seems 
trivially easy to underflow the stack into la-la land. (For example: . . .S 
after a fresh boot will get it stuck spewing memory all over the screen)

Has anyone actually used MFORTH for more than just simple tests? Is there maybe 
some hardware quirks involved here that don't exist on the Virtual-T emulator?

 

Figured I'd cast this one out and see if anyone bites.

-Alex


-- 

Disclaimer: Any resemblance between the above views and those of my employer, 
my terminal, or the view out my window are purely coincidental.  Any 
resemblance between the above and my own views is non-deterministic.  The 
question of the existence of views in the absence of anyone to hold them is 
left as an exercise for the reader.
The question of the existence of the reader is left as an exercise for the 
second god coefficient.  (A discussion of non-orthogonal, non-integral 
polytheism is beyond the scope of this article.) Thanks /usr/games/fortune

Re: [M100] Does anyone actually use MFORTH?

[Jeffrey Birt]

| Modifying .S to indicate a stack underflow error would be reasonable. It's a 
debugging tool, and not used by programs so it doesn't impact performance.



I’m not sure how that would work since .S has no idea what you think should be 
on the stack at any given time. It can only show you what is there now. 

Most of the issues I had getting started was forgetting the effect on the stack 
of operations I was carrying out, forgetting I needed to do DUP first, etc. I 
wound up doing a lot of ‘paper coding’, writing down each word on a different 
line and comment to the left of it was the stack contents would be after it was 
done. This was a great benefit to seeing what was happening.

 

Jeff Birt

 

From: M100  On Behalf Of John R. Hogerhuis
Sent: Tuesday, March 30, 2021 2:54 AM
To: m...@bitchin100.com
Subject: Re: [M100] Does anyone actually use MFORTH?

 

 

 

Re: [M100] Does anyone actually use MFORTH?

[Jeffrey Birt]

This is the default behavior for most all vintage 8-bit Forth implementations. 
To do a bounds check might take 6-10 machine cycles for every word. This does 
not seem like a lot, but it would have a noticeable impact on performance. 

 

When I ventured Forth a few years ago I found that Forth Inc has a PC based 
Forth Dev system that is pretty forgiving and a good way to learn without 
crashing a machine. https://www.forth.com/ . There is also a good online Forth 
tutorial with a web based Forth implementation: 
https://skilldrick.github.io/easyforth/ 

 

I got the most out of DurexForth which is a modern Forth implementation on the 
C64. You still get the vintage goodness but with a good VI like editor and 
actual file support rather than the super goofy and crude typical Forth screens 
and blocks. I did a few cheesy Forth videos at the time too: 
https://www.youtube.com/watch?v=TXIDqptXmiM (lots of links in the description).

 

Jeff Birt

 

From: M100  On Behalf Of Alex ...
Sent: Sunday, March 28, 2021 9:39 PM
To: Model 100 Discussion 
Subject: [M100] Does anyone actually use MFORTH?

 

Hello Tandy laptop nerds,

So I've been reading Leo Brodie's "Starting Forth" and using my '102 as a 
playground / labrat. There's been a few inconsistencies I expected and can live 
with/work around, but I've noticed what seems like really bad bugs. It seems 
trivially easy to underflow the stack into la-la land. (For example: . . .S 
after a fresh boot will get it stuck spewing memory all over the screen)

Has anyone actually used MFORTH for more than just simple tests? Is there maybe 
some hardware quirks involved here that don't exist on the Virtual-T emulator?

 

Figured I'd cast this one out and see if anyone bites.

-Alex


-- 

Disclaimer: Any resemblance between the above views and those of my employer, 
my terminal, or the view out my window are purely coincidental.  Any 
resemblance between the above and my own views is non-deterministic.  The 
question of the existence of views in the absence of anyone to hold them is 
left as an exercise for the reader.
The question of the existence of the reader is left as an exercise for the 
second god coefficient.  (A discussion of non-orthogonal, non-integral 
polytheism is beyond the scope of this article.) Thanks /usr/games/fortune

Re: [M100] In over my head? Or a Challenge!!

[Jeffrey Birt]

Most people use Isopropyl Alcohol (IPA) I tend to use denatured alcohol 
(methylated spirits) as I can get it locally and inexpensively. Each type works 
a little better as a solvent on different types of things. 

Jeff Birt

-Original Message-
From: M100  On Behalf Of Daryl Tester
Sent: Thursday, March 25, 2021 8:39 PM
To: m...@bitchin100.com
Subject: Re: [M100] In over my head? Or a Challenge!!

On 24/3/21 11:49 pm, Jeffrey Birt wrote:

> I suspect it would work by itself, but it will take a lot of it. I 
> have used alcohol followed by a typical flux/PCB cleaner product which 
> works (to save on the more expensive flux cleaner).

A transcontinental question - what type of alcohol are y'all talking about here 
- isopropyl or something else?

Cheers,
   --dt

Re: [M100] Broken NEC 8201a

[Jeffrey Birt]

The black screen is an indication that the LCD is getting power but not
getting initialized properly. This is most likely because the system is not
booting properly. The RAM modules can fail causing a no boot situation, or
it might be stuck in rest, etc. 

If you want, I'll have a crack at repairing it. They are very similar to the
M100/T102 as far as fixing one.

 

Jeff Birt

 

From: M100  On Behalf Of Robert J.
Hutchins
Sent: Wednesday, March 24, 2021 11:50 AM
To: m100@lists.bitchin100.com
Subject: [M100] Broken NEC 8201a

 

I have an NEC 8201a that will not run. 

On startup I get the black screen that does respond to the contrast control.

I don't believe it is the typical capacitor problem. I have checked a few
voltages and they appear OK.

The unit is in good physical condition.

I also have several Model 100s and a 102 which I have been able to upgrade
the ROMs to Y2K spec and manage a few repairs on.

I am of two minds about the NEC though. 

I might just sell it as is (make an offer?) or if someone would like to have
a go at repairing it, I would be happy to pay for that.

 

Please advise.

 

Thank you 

Robert J. Hutchins

 

 

Re: [M100] In over my head? Or a Challenge!!

[Jeffrey Birt]

I suspect it would work by itself, but it will take a lot of it. I have used 
alcohol followed by a typical flux/PCB cleaner product which works (to save on 
the more expensive flux cleaner).

 

Jeff Birt

 

From: M100  On Behalf Of Stephen Adolph
Sent: Wednesday, March 24, 2021 8:10 AM
To: m...@bitchin100.com
Subject: Re: [M100] In over my head? Or a Challenge!!

 

wrt cleaning the PCB, would a standard flux remover also work?



 

On Wed, Mar 24, 2021 at 8:52 AM Jeffrey Birt mailto:bir...@soigeneris.com> > wrote:

I was also reminded this morning, by another email, of the evils of the flux 
used on the M100. It can turn conductive and cause everything from the machine 
being stuck in reset, to power supply issues to fantom key presses. It is also 
a pain to clean off. I like to add about 10% glycerin to 90% alcohol (99% 
alcohol), paint it on the back of the PCB, wait 10 minutes and scrub it with a 
toothbrush, flush with alcohol and repeat. If you only have alcohol that will 
work too. I think the glycerin helps as it increases the viscosity enough to 
keep the alcohol in place.

 

Jeff Birt

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Brad Grier
Sent: Tuesday, March 23, 2021 8:43 PM
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] In over my head? Or a Challenge!!

 

Thanks Jeff! I just watched that video and it was *very* helpful. I may have 
gotten ahead of myself in the diagnosis so looking forward to putting some of 
your techniques to use. I'm thinking I can do most basic testing with my 
multimeter, but should probably look at getting a proper o-scope in the near 
future. Tempted by those cheap ones but they don't go into the 2mhz range :(

 

Thanks again for your advice -- it's appreciated.

 

--Brad

 

On Tue, Mar 23, 2021 at 8:00 AM Jeffrey Birt mailto:bir...@soigeneris.com> > wrote:

I did a video a while back about the first steps in troubleshooting a vintage 
computer. In a nutshell think ‘PCR’ Power, Clock, Reset. Make sure that all 
power supply rails are functional, then check that you have a good clock signal 
and finally check for a properly working reset. Without these 3 basic things 
nothing else will work and you can get confusing results. For example a reset 
that does not work properly can cause everything from not booting at all (held 
in reset) to the system coming up various random states as things were not 
properly reset. 

Jeff Birt

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Brad Grier
Sent: Monday, March 22, 2021 10:33 PM
To: m100@lists.bitchin100.com <mailto:m100@lists.bitchin100.com> 
Subject: [M100] In over my head? Or a Challenge!!

 

Hi everyone, as the subject line says, am I in over my head (for someone with 
old basic electronics knowledge), or is this a worthy challenge?

[TL;DR] System symptoms: Won't power the screen, BASIC doesn't really work, 
unusual voltages on LCD connector pins. What to do? And why??

 

A few months ago I received a M100 that wasn't really working. Initial symptom 
is no display. I was looking at this as a learning experience -- to see if I 
could do some simple fixes and get it going again, and dust off my ancient 
basic electronics knowledge. I only have a multimeter, so I knew this could be 
a challenge.

 

Initial testing revealed that it did power up and will 'Beep' on command 
(blindly entering Basic and typing Beep). 

 

LCD does work -- I connected it to my NEC PC-8201a and had a functioning 
display (with a tiny line of dead pixels in zone 1). So I'm ruling out a bad 
LCD.

 

The mainboard looks fine. No obvious scratches or leaking battery or caps. No 
obviously damaged components. No staining of any kind other than the 
standard-issue coating of flux (which I've read can turn conductive so I'm open 
to cleaning all that off too). 

 

Display-related transistors and diodes (according to the troubleshooting 
flowchart) check out. The caps look great too -- but I haven't desoldered each 
of them to test them out of circuit. I've read recommendations to recap anyway, 
but I'm not sure it'd be worth it if the other problems aren't related to bad 
caps.

 

Voltages on the LCD Connector pins seemed weird when compared with my NEC 
PC8201a. Image here:  <https://imgur.com/a/xfNIdF1> https://imgur.com/a/xfNIdF1 
Related to caps? Something else? The LCD is getting these voltages (the cable 
is fine).

 

So now I'm thinking there might be something with the logic. So I tried typing 
a simple basic program, blindly, but it's a short program so I'm pretty sure I 
got it in properly:
10 beep

20 goto 10

 

Nothing. No string of beeps. 

And after that, a simple beep won't work either. 

 

But, power cycle or reset, enter basic, type beep, it works.

beep:beep:beep also works. Now I'm thinking partially bad RAM? Or RAM select 
logic?

 

So, two issues (display and BASIC), or is this all a case of a bunc

Re: [M100] In over my head? Or a Challenge!!

[Jeffrey Birt]

I was also reminded this morning, by another email, of the evils of the flux 
used on the M100. It can turn conductive and cause everything from the machine 
being stuck in reset, to power supply issues to fantom key presses. It is also 
a pain to clean off. I like to add about 10% glycerin to 90% alcohol (99% 
alcohol), paint it on the back of the PCB, wait 10 minutes and scrub it with a 
toothbrush, flush with alcohol and repeat. If you only have alcohol that will 
work too. I think the glycerin helps as it increases the viscosity enough to 
keep the alcohol in place.

 

Jeff Birt

 

From: M100  On Behalf Of Brad Grier
Sent: Tuesday, March 23, 2021 8:43 PM
To: m...@bitchin100.com
Subject: Re: [M100] In over my head? Or a Challenge!!

 

Thanks Jeff! I just watched that video and it was *very* helpful. I may have 
gotten ahead of myself in the diagnosis so looking forward to putting some of 
your techniques to use. I'm thinking I can do most basic testing with my 
multimeter, but should probably look at getting a proper o-scope in the near 
future. Tempted by those cheap ones but they don't go into the 2mhz range :(

 

Thanks again for your advice -- it's appreciated.

 

--Brad

 

On Tue, Mar 23, 2021 at 8:00 AM Jeffrey Birt mailto:bir...@soigeneris.com> > wrote:

I did a video a while back about the first steps in troubleshooting a vintage 
computer. In a nutshell think ‘PCR’ Power, Clock, Reset. Make sure that all 
power supply rails are functional, then check that you have a good clock signal 
and finally check for a properly working reset. Without these 3 basic things 
nothing else will work and you can get confusing results. For example a reset 
that does not work properly can cause everything from not booting at all (held 
in reset) to the system coming up various random states as things were not 
properly reset. 

Jeff Birt

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Brad Grier
Sent: Monday, March 22, 2021 10:33 PM
To: m100@lists.bitchin100.com <mailto:m100@lists.bitchin100.com> 
Subject: [M100] In over my head? Or a Challenge!!

 

Hi everyone, as the subject line says, am I in over my head (for someone with 
old basic electronics knowledge), or is this a worthy challenge?

[TL;DR] System symptoms: Won't power the screen, BASIC doesn't really work, 
unusual voltages on LCD connector pins. What to do? And why??

 

A few months ago I received a M100 that wasn't really working. Initial symptom 
is no display. I was looking at this as a learning experience -- to see if I 
could do some simple fixes and get it going again, and dust off my ancient 
basic electronics knowledge. I only have a multimeter, so I knew this could be 
a challenge.

 

Initial testing revealed that it did power up and will 'Beep' on command 
(blindly entering Basic and typing Beep). 

 

LCD does work -- I connected it to my NEC PC-8201a and had a functioning 
display (with a tiny line of dead pixels in zone 1). So I'm ruling out a bad 
LCD.

 

The mainboard looks fine. No obvious scratches or leaking battery or caps. No 
obviously damaged components. No staining of any kind other than the 
standard-issue coating of flux (which I've read can turn conductive so I'm open 
to cleaning all that off too). 

 

Display-related transistors and diodes (according to the troubleshooting 
flowchart) check out. The caps look great too -- but I haven't desoldered each 
of them to test them out of circuit. I've read recommendations to recap anyway, 
but I'm not sure it'd be worth it if the other problems aren't related to bad 
caps.

 

Voltages on the LCD Connector pins seemed weird when compared with my NEC 
PC8201a. Image here:  <https://imgur.com/a/xfNIdF1> https://imgur.com/a/xfNIdF1 
Related to caps? Something else? The LCD is getting these voltages (the cable 
is fine).

 

So now I'm thinking there might be something with the logic. So I tried typing 
a simple basic program, blindly, but it's a short program so I'm pretty sure I 
got it in properly:
10 beep

20 goto 10

 

Nothing. No string of beeps. 

And after that, a simple beep won't work either. 

 

But, power cycle or reset, enter basic, type beep, it works.

beep:beep:beep also works. Now I'm thinking partially bad RAM? Or RAM select 
logic?

 

So, two issues (display and BASIC), or is this all a case of a bunch of 
invisibly bad caps and I should just bite the bullet, desolder a few and test 
them.

 

Thoughts? Ideas? What am I missing? Is this thing destined for a parts computer 
or could it be a good challenge to heal it up? All advice appreciated :)

 

--Brad

 

 

 

 

 

 

 

 

 

 

-- 

-- 
Brad Grier

 

 




 

-- 

-- 
Brad Grier

 

 

Re: [M100] In over my head? Or a Challenge!!

[Jeffrey Birt]

I did a video a while back about the first steps in troubleshooting a vintage 
computer. In a nutshell think ‘PCR’ Power, Clock, Reset. Make sure that all 
power supply rails are functional, then check that you have a good clock signal 
and finally check for a properly working reset. Without these 3 basic things 
nothing else will work and you can get confusing results. For example a reset 
that does not work properly can cause everything from not booting at all (held 
in reset) to the system coming up various random states as things were not 
properly reset. 

Jeff Birt

 

From: M100  On Behalf Of Brad Grier
Sent: Monday, March 22, 2021 10:33 PM
To: m100@lists.bitchin100.com
Subject: [M100] In over my head? Or a Challenge!!

 

Hi everyone, as the subject line says, am I in over my head (for someone with 
old basic electronics knowledge), or is this a worthy challenge?

[TL;DR] System symptoms: Won't power the screen, BASIC doesn't really work, 
unusual voltages on LCD connector pins. What to do? And why??

 

A few months ago I received a M100 that wasn't really working. Initial symptom 
is no display. I was looking at this as a learning experience -- to see if I 
could do some simple fixes and get it going again, and dust off my ancient 
basic electronics knowledge. I only have a multimeter, so I knew this could be 
a challenge.

 

Initial testing revealed that it did power up and will 'Beep' on command 
(blindly entering Basic and typing Beep). 

 

LCD does work -- I connected it to my NEC PC-8201a and had a functioning 
display (with a tiny line of dead pixels in zone 1). So I'm ruling out a bad 
LCD.

 

The mainboard looks fine. No obvious scratches or leaking battery or caps. No 
obviously damaged components. No staining of any kind other than the 
standard-issue coating of flux (which I've read can turn conductive so I'm open 
to cleaning all that off too). 

 

Display-related transistors and diodes (according to the troubleshooting 
flowchart) check out. The caps look great too -- but I haven't desoldered each 
of them to test them out of circuit. I've read recommendations to recap anyway, 
but I'm not sure it'd be worth it if the other problems aren't related to bad 
caps.

 

Voltages on the LCD Connector pins seemed weird when compared with my NEC 
PC8201a. Image here:   https://imgur.com/a/xfNIdF1 
Related to caps? Something else? The LCD is getting these voltages (the cable 
is fine).

 

So now I'm thinking there might be something with the logic. So I tried typing 
a simple basic program, blindly, but it's a short program so I'm pretty sure I 
got it in properly:
10 beep

20 goto 10

 

Nothing. No string of beeps. 

And after that, a simple beep won't work either. 

 

But, power cycle or reset, enter basic, type beep, it works.

beep:beep:beep also works. Now I'm thinking partially bad RAM? Or RAM select 
logic?

 

So, two issues (display and BASIC), or is this all a case of a bunch of 
invisibly bad caps and I should just bite the bullet, desolder a few and test 
them.

 

Thoughts? Ideas? What am I missing? Is this thing destined for a parts computer 
or could it be a good challenge to heal it up? All advice appreciated :)

 

--Brad

 

 

 

 

 

 

 

 

 

 

-- 

-- 
Brad Grier

 

 

Re: [M100] Need help fixing VEE on M100

[Jeffrey Birt]

On the M100s I have found most of the caps tend to leak (and cause PCB damage). 
While I am NOT a proponent of 'recapping' every piece of vintage gear out there 
on the M100 I do a full recap on every one of them. 

The -5V also goes to the RS-232 circuitry so if something is amiss there it can 
load down the supply. My best guess though is that if you replace the rest of 
the electrolytics on the board and clean up any damage caused by the leaking 
ones that will solve the issue. I have had a few odd power supply related 
issues caused by invisible conductive gunk on the top side of the PCB and/or 
the flux they applied to the bottom of the PCB with a butter knife, turning 
conductive. 

Jeff Birt 

-Original Message-
From: M100  On Behalf Of Eric LK
Sent: Sunday, March 21, 2021 2:05 AM
To: m100@lists.bitchin100.com
Subject: [M100] Need help fixing VEE on M100

About 6 months ago, my M100's LCD contrast was very weak and impossible to use.
Following your advice, I changed C82 and C85 . That gave me a solid -5V for VEE 
and the contrast was back to normal.

My problem is that 6 months later, I can still read the screen
(mostly) but my VEE is now back to -3V.

I'm tempted to replace C82 and C85 again, but I think it's weird to get the 
same failure so quickly after a fix (both new capacitors were new from mouser).

Do you see anything else I should check regarding this issue?

Eric

Re: [M100] TPDD service manual

[Jeffrey Birt]

It is not that it is just ‘less sensitive’. I’m really stretching my memory 
from the research I did on the subject here but as I recall the composition of 
the coating of the disk is different (something like the particle size of the 
ferrous material being smaller). To flip the domain on this new HD coating 
requires a stronger magnetic field. The DD drive cannot output a strong enough 
magnetic field to properly magnetize the new HD coating.

 

Jeff Birt

 

From: M100  On Behalf Of Brian White
Sent: Saturday, March 20, 2021 8:49 AM
To: m...@bitchin100.com
Subject: Re: [M100] TPDD service manual

 

Not that it changes anything, but I thought the problem with the density 
difference was that the lower density drive would put out a stronger signal 
needed for the less sensitive media, and so the problem with using hd media in 
a dd drive would be that the dd drive would overdrive the media making a 
distorted signal?

 

Is it actually  the opposite, that the way they achieved higher density is by 
using less sensitive media driven by a stonger head?

 

On Sat, Mar 20, 2021, 8:35 AM Jeffrey Birt mailto:bir...@soigeneris.com> > wrote:

Oh, sorry I misread what you wrote. But to your point, that could be done. I 
use a SuperCard Pro to image floppies which is just a PIC uC with supporting HW 
and some spiffy firmware/software. It can image TPDD1/2 disks easily using a 
standard 3.5” 1.44MB drive. The software does know how to interpret the data, 
it is just a flux map. The .SCP format is well documented though so one could 
figure out how to recreate the disk file structure from it.

There is a similar device called the Flux Engine that has already done the file 
system decoding and can image/interpret TPDD disks using a standard 3.5” 1.44MB 
drive.

 

Jeff Birt

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Stephen Adolph
Sent: Saturday, March 20, 2021 7:28 AM
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] TPDD service manual

 

not exactly the point I was trying to make.

pretty clearly a TPDD1 cannot use an HD floppy.  

but a small microcontroller that speaks TPDD protocol and has integrated FDC 
function could interface with a modern FDD.

..steve

 

On Sat, Mar 20, 2021 at 8:20 AM Jeffrey Birt mailto:bir...@soigeneris.com> > wrote:

High density disks, both 3.5 and 5.25, require a much higher flux level to 
write. A system designed for DD disks will not be able to write to them 
reliably. Some folks have tried HD 3.5” disks in an Amiga or Mac for example 
only to find that it reads for a while but after a few weeks or months it no 
longer does. You can generally write to lower density disks with a HD drive. 
The exception being that it is best to write 360K 5.25”disks with a 360K drive 
as the head on these drives was physically larger and the narrower track 
written by a higher density drive may not work well on all 360K drives.

My take on the TPDD is that it was designed to be cheap (simple) and portable. 
Thus, they used a simple 8-bit micro to control everything and not one of the 
floppy disc controller ASICs that were available at that time. But, they wound 
up with something that would run on AA batteries and use standard media at the 
time even if the storage capacity was limited.

 

Jeff Birt

 

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Stephen Adolph
Sent: Saturday, March 20, 2021 5:59 AM
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] TPDD service manual

 

this is quite interesting, and nice detective work.

It would seem like an interesting use case here could be to modify this 
firmware to make it target a standard 1.44MB floppy disk drive.

Maybe it would seem a bit backwards because SD cards are more mainstream, but 
still interesting to think about.

 

I see you have the disassembly in place.

 

Re: [M100] TPDD service manual

[Jeffrey Birt]

Oh, sorry I misread what you wrote. But to your point, that could be done. I 
use a SuperCard Pro to image floppies which is just a PIC uC with supporting HW 
and some spiffy firmware/software. It can image TPDD1/2 disks easily using a 
standard 3.5” 1.44MB drive. The software does know how to interpret the data, 
it is just a flux map. The .SCP format is well documented though so one could 
figure out how to recreate the disk file structure from it.

There is a similar device called the Flux Engine that has already done the file 
system decoding and can image/interpret TPDD disks using a standard 3.5” 1.44MB 
drive.

 

Jeff Birt

 

From: M100  On Behalf Of Stephen Adolph
Sent: Saturday, March 20, 2021 7:28 AM
To: m...@bitchin100.com
Subject: Re: [M100] TPDD service manual

 

not exactly the point I was trying to make.

pretty clearly a TPDD1 cannot use an HD floppy.  

but a small microcontroller that speaks TPDD protocol and has integrated FDC 
function could interface with a modern FDD.

..steve

 

On Sat, Mar 20, 2021 at 8:20 AM Jeffrey Birt mailto:bir...@soigeneris.com> > wrote:

High density disks, both 3.5 and 5.25, require a much higher flux level to 
write. A system designed for DD disks will not be able to write to them 
reliably. Some folks have tried HD 3.5” disks in an Amiga or Mac for example 
only to find that it reads for a while but after a few weeks or months it no 
longer does. You can generally write to lower density disks with a HD drive. 
The exception being that it is best to write 360K 5.25”disks with a 360K drive 
as the head on these drives was physically larger and the narrower track 
written by a higher density drive may not work well on all 360K drives.

My take on the TPDD is that it was designed to be cheap (simple) and portable. 
Thus, they used a simple 8-bit micro to control everything and not one of the 
floppy disc controller ASICs that were available at that time. But, they wound 
up with something that would run on AA batteries and use standard media at the 
time even if the storage capacity was limited.

 

Jeff Birt

 

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Stephen Adolph
Sent: Saturday, March 20, 2021 5:59 AM
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] TPDD service manual

 

this is quite interesting, and nice detective work.

It would seem like an interesting use case here could be to modify this 
firmware to make it target a standard 1.44MB floppy disk drive.

Maybe it would seem a bit backwards because SD cards are more mainstream, but 
still interesting to think about.

 

I see you have the disassembly in place.

 

Re: [M100] TPDD service manual

[Jeffrey Birt]

High density disks, both 3.5 and 5.25, require a much higher flux level to 
write. A system designed for DD disks will not be able to write to them 
reliably. Some folks have tried HD 3.5” disks in an Amiga or Mac for example 
only to find that it reads for a while but after a few weeks or months it no 
longer does. You can generally write to lower density disks with a HD drive. 
The exception being that it is best to write 360K 5.25”disks with a 360K drive 
as the head on these drives was physically larger and the narrower track 
written by a higher density drive may not work well on all 360K drives.

My take on the TPDD is that it was designed to be cheap (simple) and portable. 
Thus, they used a simple 8-bit micro to control everything and not one of the 
floppy disc controller ASICs that were available at that time. But, they wound 
up with something that would run on AA batteries and use standard media at the 
time even if the storage capacity was limited.

 

Jeff Birt

 

 

From: M100  On Behalf Of Stephen Adolph
Sent: Saturday, March 20, 2021 5:59 AM
To: m...@bitchin100.com
Subject: Re: [M100] TPDD service manual

 

this is quite interesting, and nice detective work.

It would seem like an interesting use case here could be to modify this 
firmware to make it target a standard 1.44MB floppy disk drive.

Maybe it would seem a bit backwards because SD cards are more mainstream, but 
still interesting to think about.

 

I see you have the disassembly in place.

 

On Fri, Mar 19, 2021 at 8:36 PM Darren Clark mailto:biggran...@gmail.com> > wrote:

There are 2 memory modes on that processor, Mode0 which uses the internal RAM 
and ROM (which is how the PDD is being used), and Mode 1 which addresses 
external memory and masks the internal ROM. The modes are selected at startup 
and can't be switched until the chip is reset.

Re: [M100] TPDD service manual

[Jeffrey Birt]

Awesome, thanks for sharing.

 

Jeff Birt

 

From: M100  On Behalf Of Stephen Adolph
Sent: Thursday, March 18, 2021 7:14 PM
To: m...@bitchin100.com
Subject: Re: [M100] TPDD service manual

 

John, couldn't make that work..login prevented.

 

so I did it brute-force.

https://bitchin100.com/wiki/index.php?title=TPDD_Service_Manual

 

 

 

 

On Thu, Mar 18, 2021 at 7:43 PM John R. Hogerhuis mailto:jho...@pobox.com> > wrote:

You have to be logged in to upload

http://bitchin100.com/wiki/index.php?title=Special:Upload

 

On Thu, Mar 18, 2021 at 4:15 PM Stephen Adolph mailto:twospru...@gmail.com> > wrote:

ah  good idea.  is there a files area?

 

 

On Thu, Mar 18, 2021 at 7:06 PM John R. Hogerhuis mailto:jho...@pobox.com> > wrote:

Very cool!

You can upload it to Bitchin100 wiki. The File Uploads feature.

 

-- John.

 

On Thu, Mar 18, 2021 at 3:56 PM Stephen Adolph mailto:twospru...@gmail.com> > wrote:

Via a user on facebook, the TPDD service manual has been found!

Who knew we would still be discovering documents in 2021.

 

Need to make arrangements to post this at Club100.

It is too large to send to the mailing list..

Steve

 

Re: [M100] molex ic socket

[Jeffrey Birt]

If they won’t ship directly to you, I would be happy to forward them to you. 
I’m in the USA.

 

Jeff

 

From: M100  On Behalf Of Stephen Adolph
Sent: Thursday, March 18, 2021 6:21 AM
To: m...@bitchin100.com
Subject: Re: [M100] molex ic socket

 

Too  ad for me this seller wont ship to Canada.  Although he doesnt explicitly 
list canada as an exclusion.  I wonder if I should just attempt a purchase.

On Tuesday, March 16, 2021, Brian K. White mailto:b.kenyo...@gmail.com> > wrote:

There's some new sockets on ebay
https://www.ebay.com/itm/153988317907

I still have a bunch and will give or sell cheap a few to whoever needs a them 
for repairs & spares, but still, I figured this should be pointed out.

Anyone doing repairs should probably go scoop some up.

-- 
bkw

Re: [M100] PC-8201 "wide" DIL socket?

[Jeffrey Birt]

I was wrong about the comment. Gadget was saying he had inherited some when a 
friend passed and did not know what they were for until seeing the video.

 

Jeff Birt

 

From: M100  On Behalf Of Jeffrey Birt
Sent: Tuesday, March 16, 2021 6:16 PM
To: m...@bitchin100.com
Subject: Re: [M100] PC-8201 "wide" DIL socket?

 

There was a comment from GadgetUK on one of the M100 videos I did where he 
mentioned the RAM module looked like the one used in something else. I’ll see 
if I can look up that comment.

 

Jeff Birt

 

From: M100 mailto:m100-boun...@lists.bitchin100.com> > On Behalf Of Stephen Adolph
Sent: Tuesday, March 16, 2021 5:32 PM
To: m...@bitchin100.com <mailto:m...@bitchin100.com> 
Subject: Re: [M100] PC-8201 "wide" DIL socket?

 

Yes I bought 2 of them.  That was 2016?  Sheesh.

 

They are made for that pinout.  So, was there some other application for the 
"M100 ram module"?

 

Some NEC product?



On Tuesday, March 16, 2021, Brian K. White mailto:b.kenyo...@gmail.com> > wrote:

On 3/16/21 12:24 PM, Brian K. White wrote:

On 3/16/21 11:52 AM, Stephen Adolph wrote:

The NEC laptops use a wider than .600 DIL socket for the memory modules.

Anyone ever seen those sockets available for order, or have a part number?

I don't think I have ever come across those anywhere else.

thx
Steve



Mine just has separate single-row headers, not a single socket holding both 
rows.

Same size and same modules as Model 100.


I did once find these NEC ram modules on ebay though that do have a one-piece 
frame for the pins at 0.7"

It's curious. The sram chip, the pcb, and even the pin frame are all labeled 
NEC, but as far as I can tell from any other pictures I've ever seen, PC-8201 
did not ship with these. But they DO work in both my 8201a and my Model 100's.

If NEC didn't make these for their computer which they DO work in, then what 
the heck WERE they made for?

The seller was in Romania and had more than the 8 I got, but sold out a few 
months later.

Just for giggles, I filled my 8201A with them, so I have an NEC computer filled 
with actual NEC ram.

https://photos.app.goo.gl/qCnkqKSbatZmoyyw8

-- 

bkw

Re: [M100] nec pc-8300

[Jeffrey Birt]

Hi,

 

If you are in the USA I would be interested. The PC-8300 is one that still 
eludes me.

 

Jeff Birt

 

From: M100  On Behalf Of Montana Quiring
Sent: Tuesday, March 16, 2021 9:41 PM
To: m...@bitchin100.com
Subject: [M100] nec pc-8300

 

Hello everyone,

 

I'm a long time lurker. I used to be involved in the M100 community and made 
numerous purchases and had many conversations with Rick Hanson back in the day.

Thanks for keeping the community alive. I read the emails from time to time and 
enjoy the conversation.

I'm trying to pair down my stuff in preparation for moving over the next year 
or so and am going to potentially sell some items starting with a working NEC 
PC-8300.

 

I know some of the groups I'm on are particular about posts pertaining to 
selling items.

Sorry but I don't recall this group's position on that.

Is it ok if I talk about it here?




Regards,
-Montana