Re: DEC Pro 350/380 Memory Cards - Interchangeability?

[Eric Smith]

On Wed, Aug 31, 2016 at 6:42 AM, Paul Koning  wrote:
> Yes, the one I saw when I made that comment is an MSM51V18165F by Lapis, a 1M 
> by 16 "fast page mode" EDO DRAM.

If it's EDO, it may not be compatible with systems that weren't
designed for EDO, and since none of the 16-pin parts were EDO, I'd
avoid it.

"Normal" and FPM memory stops driving the data output when CAS is
deasserted, regardless of the state of RAS.  EDO continues driving the
data output even with CAS deasserted, unless RAS is also deasserted.

Re: Wanted - two 27C010-capable EPROM emulators

[Glen Slick]

On Wed, Aug 31, 2016 at 3:07 PM, Philip Pemberton
 wrote:
>
> I could swear these things were as common as housebricks on ebay a year
> or so ago, but now they're not quite so common...
>

Grammar Engine PromICE units show up on eBay from time to time in the
US sometimes around the $20 range for just the box alone. Then you
need to supply your own power adapter and ribbon cable DIP plug
adapters.

Currently I only see a single example, asking $67 but it's a dual unit
P2010-AI that would emulate up to two 27C010 EPROMs in a single box:
http://www.ebay.com/itm/261235940330

Too bad shipping would almost double the price to you.

Re: X Windows System Design Principles, a lecture by James Gettys

[Tony Aiuto]

I used to tell people he wrote the *getty* program. Of course, that was a
long time ago, when people actually used serial terminals.

On Wed, Aug 31, 2016 at 11:03 AM, tim lindner  wrote:

> I think it is dated 1988.
>
> https://www.youtube.com/watch?v=KdmNHM9BKY0
>
> Interesting fact: His name is Gettys.
>
> Interesting quote: "We should never have done [the] Arc [drawing
> command], we should have done some spline implementation."
>
>
>
>
> --
> --
> tim lindner
>
> "Proper User Policy apparently means Simon Says."
>

Wanted - two 27C010-capable EPROM emulators

[Philip Pemberton]

Hi there,

Does anyone have a pair of spare EPROM emulators which are capable of
emulating 27C010 EPROMs?
Ideally two identical ones, but that's optional.


I'm trying to reverse-engineer a Securicor Datatrak MkII navigation
receiver and build a signal generator which can emulate a chain of
Datatrak transmitters. I'm part of the way there, but I've hit something
of an impasse:


  * My emulator isn't good enough to run the firmware on a PC (it
crashes when the RTOS starts to boot).

  * My knowledge of the hardware is full of holes (especially the
simple-but-custom ASIC). Porting a monitor ROM using EPROMs would take a
fair while, even with the HP16700A to use as a "debugger". I'd like to
try patching the firmware, but with bare EPROMs that'll take a while to
get right.


I could swear these things were as common as housebricks on ebay a year
or so ago, but now they're not quite so common...


Incidentally, if someone (preferable in the EEA) has a spare HP 16717A
acquisition card (for the 16700A series logic analysers) for sale, I'd
be very interested in getting another one -- my second 16717A seems to
have died while in storage, and spying on the 68k has eaten up all the
pod inputs on my one working card.


Thanks,
-- 
Phil.
classic...@philpem.me.uk
http://www.philpem.me.uk/

Re: BA123 Side panels and Stuck TK50

[Douglas Taylor]

On 8/30/2016 4:54 PM, shad wrote:

Hello,


The same cabinet has a TK50 and I foolishly put a cartridge into it and
now it won't come out.  It is called being 'stuck'.  How do proceed to
get this TK50 cartridge out?


Error 'stuck' means that the tape has been "glued" to the head because 
of the effect

of the tape binder being converted to adhesive due to age and moisture.
You can remove the cartridge in this way:
- pull the drive out of the machine
- carefully unscrew the metal cover over the internal reel and the 
head to expose it
- slowly insert a paper sheet between the tape and the head, in the 
same direction of the tape, to detach it without damage
- slowly rotate the front motor (from bottom side) in way to rewind 
all the tape from the back reel to the cartridge reel

- detach the tape leader if necessary
- now keep the electromagnetic cartridge unlock mechanism pressed, and 
remove the cartridge from the drive


A tape in this condition of striction is probably unusable anyway, 
unless you back it up a little in an oven,

but even so it could be readable just for a couple of hours


I removed the drive from the MicroVax and took off the metal cover on 
the TK50.  There was about 1/2 inch of tape on the takeup reel and it 
moved freely.
The documentation on bitsavers told me what I should have known in the 
first place.  The Green and Red lights indicate the health of the drive.
When the drive first powers on the red light should be on during a brief 
diagnostic test, then the red light should go out and the green light 
should come on indicating that the drive has passed internal tests and 
is ready.  My TK50 never lights the green light and before I cleaned it 
out the red light would blink indicating an internal fault.

Geez I hate these things.

The Bitsavers doc had a section for bench service and interpreting error 
codes, does anyone know how to get these codes?   Is there a PDP11 or 
VAX diagnostic that reports these codes?  Can you get at them from ODT 
or the VAX console?


I still would like to rewind the tape and remove the cartridge, but it 
looks like a difficult task to rewind by hand.






Also, the TQK50 controller never saw the drive and I was wondering if
the PROM's (after 30 years) on the board lose their data?


Well, I never seen an UV-EPROM loose it's data, unless the erase 
window cover is missing and the memory exposed to the sun light.


Andrea

Re: How to build an ASCII CRT terminal, circa 1967

[COURYHOUSE]

same as univac  uniscope  or? 
 
 
In a message dated 8/31/2016 8:41:06 A.M. US Mountain Standard Time,  
a...@bitsavers.org writes:



On 8/31/16 8:35 AM, Paul Berger wrote:
> it would be  possible  to have it generate 7 bit ASCII
> code by using an  appropriately "programmed" interposer under the keys.

it does say the  keyboard generates ASCII on pg 3-2 of the maint  manual..

Re: How to build an ASCII CRT terminal, circa 1967

[Mike Stein]

Oops... should have read:

Looks like the folder changed from 70-750 to 70-752:

http://bitsavers.trailing-edge.com/pdf/rca/terminal/70_752/70-01-752-U_Model_70_752_Video_Data_Terminal_Maintenance_Manual_Oct73.pdf

- Original Message - 
From: "Eric Christopherson" 
To: "General Discussion: On-Topic and Off-Topic Posts" 
Sent: Wednesday, August 31, 2016 12:09 PM
Subject: Re: How to build an ASCII CRT terminal, circa 1967


> On Wed, Aug 31, 2016 at 10:15 AM, Al Kossow  wrote:
> 
>> Magnetorestrictive delay lines and a charactron.
>>
>> http://bitsavers.org/pdf/rca/terminal/70_750/70-01-752-U_
>> Model_70_752_Video_Data_Terminal_Maintenance_Manual_Oct73.pdf
>>
>> We got one (no keyboard) a couple days ago with the manual. I'm still
>> cleaning it up. It had something nesting in it and
>> the inside has sunflower seed husks in it. It was made with plastic DIP
>> ICs, no idea of the logic family. The keyboard
>> was made by IBM, don't know what character code it produces. Pretty funky
>> if it encodes ASCII.
> 
> 
> That URL redirects to
> http://www.mirrorservice.org/sites/www.bitsavers.org/pdf/rca/terminal/70_750/70-01-752-U_Model_70_752_Video_Data_Terminal_Maintenance_Manual_Oct73.pdf
> , which is showing a 404.
> 
> 
> -- 
>Eric Christopherson

Re: How to build an ASCII CRT terminal, circa 1967

[Mike Stein]

Looks like the folder name changed from 70_750 to 70_752:

- Original Message - 
From: "Eric Christopherson" 
To: "General Discussion: On-Topic and Off-Topic Posts" 
Sent: Wednesday, August 31, 2016 12:09 PM
Subject: Re: How to build an ASCII CRT terminal, circa 1967


> On Wed, Aug 31, 2016 at 10:15 AM, Al Kossow  wrote:
> 
>> Magnetorestrictive delay lines and a charactron.
>>
>> http://bitsavers.org/pdf/rca/terminal/70_752/70-01-752-U_
>> Model_70_752_Video_Data_Terminal_Maintenance_Manual_Oct73.pdf
>>
>> We got one (no keyboard) a couple days ago with the manual. I'm still
>> cleaning it up. It had something nesting in it and
>> the inside has sunflower seed husks in it. It was made with plastic DIP
>> ICs, no idea of the logic family. The keyboard
>> was made by IBM, don't know what character code it produces. Pretty funky
>> if it encodes ASCII.
> 
> 
> That URL redirects to
> http://www.mirrorservice.org/sites/www.bitsavers.org/pdf/rca/terminal/70_752/70-01-752-U_Model_70_752_Video_Data_Terminal_Maintenance_Manual_Oct73.pdf
> , which is showing a 404.
> 
> 
> -- 
>Eric Christopherson

Re: How to build an ASCII CRT terminal, circa 1967

[Eric Christopherson]

On Wed, Aug 31, 2016 at 10:15 AM, Al Kossow  wrote:

> Magnetorestrictive delay lines and a charactron.
>
> http://bitsavers.org/pdf/rca/terminal/70_750/70-01-752-U_
> Model_70_752_Video_Data_Terminal_Maintenance_Manual_Oct73.pdf
>
> We got one (no keyboard) a couple days ago with the manual. I'm still
> cleaning it up. It had something nesting in it and
> the inside has sunflower seed husks in it. It was made with plastic DIP
> ICs, no idea of the logic family. The keyboard
> was made by IBM, don't know what character code it produces. Pretty funky
> if it encodes ASCII.


That URL redirects to
http://www.mirrorservice.org/sites/www.bitsavers.org/pdf/rca/terminal/70_750/70-01-752-U_Model_70_752_Video_Data_Terminal_Maintenance_Manual_Oct73.pdf
, which is showing a 404.


-- 
Eric Christopherson

Re: How to build an ASCII CRT terminal, circa 1967

[Al Kossow]

On 8/31/16 8:35 AM, Paul Berger wrote:
> it would be possible  to have it generate 7 bit ASCII
> code by using an appropriately "programmed" interposer under the keys.

it does say the keyboard generates ASCII on pg 3-2 of the maint manual..

Re: How to build an ASCII CRT terminal, circa 1967

[Paul Berger]

On 2016-08-31 12:15 PM, Al Kossow wrote:

Magnetorestrictive delay lines and a charactron.

http://bitsavers.org/pdf/rca/terminal/70_750/70-01-752-U_Model_70_752_Video_Data_Terminal_Maintenance_Manual_Oct73.pdf

We got one (no keyboard) a couple days ago with the manual. I'm still cleaning 
it up. It had something nesting in it and
the inside has sunflower seed husks in it. It was made with plastic DIP ICs, no 
idea of the logic family. The keyboard
was made by IBM, don't know what character code it produces. Pretty funky if it 
encodes ASCII.



Nice a selectric keyboard... It looks like it has links that operates a 
microswitch for each of the bails.  The bails that would get pulled when 
the filter shaft comes around would depend on the tabs present on the 
key interposers, so the key interposers would determine the coding of 
the keyboard and it would be possible  to have it generate 7 bit ASCII 
code by using an appropriately "programmed" interposer under the keys.


Paul.

How to build an ASCII CRT terminal, circa 1967

[Al Kossow]

Magnetorestrictive delay lines and a charactron.

http://bitsavers.org/pdf/rca/terminal/70_750/70-01-752-U_Model_70_752_Video_Data_Terminal_Maintenance_Manual_Oct73.pdf

We got one (no keyboard) a couple days ago with the manual. I'm still cleaning 
it up. It had something nesting in it and
the inside has sunflower seed husks in it. It was made with plastic DIP ICs, no 
idea of the logic family. The keyboard
was made by IBM, don't know what character code it produces. Pretty funky if it 
encodes ASCII.

X Windows System Design Principles, a lecture by James Gettys

[tim lindner]

I think it is dated 1988.

https://www.youtube.com/watch?v=KdmNHM9BKY0

Interesting fact: His name is Gettys.

Interesting quote: "We should never have done [the] Arc [drawing
command], we should have done some spline implementation."




-- 
--
tim lindner

"Proper User Policy apparently means Simon Says."

Re: DEC Pro 350/380 Memory Cards - Interchangeability?

[Paul Koning]

> On Aug 30, 2016, at 8:15 PM, Eric Smith  wrote:
> 
> On Tue, Aug 30, 2016 at 1:28 PM, Paul Koning  wrote:
>> Another possibility would be a current (not surplus) DRAM device such as a 
>> 1M x 16 chip, plus a couple of level shifters to go between the 3.3 V it 
>> likes and the 5V logic of the Pro.
> 
> WARNING: Most recent 1Mx16 DRAM devices are synchronous DRAM (and
> usually DDR of some description), which are NOT EVEN CLOSE to being
> electrically compatible with legacy 16-pin DRAMs, nor even the 1 Mbit
> and 4 Mbit legacy DRAMs.
> 
> Most of the ones that aren't synchronous are 3.3V parts, and won't
> work reliably if at all in a 5V system without the level shifters Paul
> mentioned.  I commonly use 74LVC245 buffers between 5V and 3.3V logic,
> when the 5V logic doesn't require a full 5V swing (e.g., Voh min of
> 2.0V for TTL-compatible parts).

Yes, the one I saw when I made that comment is an MSM51V18165F by Lapis, a 1M 
by 16 "fast page mode" EDO DRAM.  

> It does appear that ISSI still makes some 5V 1Mx16 non-synchronous
> DRAMs in either EDO or Fast Page Mode. There's a reasonable chance
> that the 5V Fast Page Mode devices would work for replacing legacy
> DRAM, and wouldn't require any level shifting. 

That would be interesting to try.

paul

RE: BA123 Side panels and Stuck TK50

[Rob Jarratt]

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of jim
> stephens
> Sent: 31 August 2016 04:08
> To: r...@jarratt.me.uk; General Discussion: On-Topic and Off-Topic Posts
> 
> Subject: Re: BA123 Side panels and Stuck TK50
> 
> I've bought a pile of drives recently, and may have one that you can
> scavenge.  However I think mine may be TK-70's though.
> 

Actually mine was a TK70, I *think* the leader is the same in both drives in
any case. If you have a spare that would be nice, but I think I may have a
spare tucked away somewhere anyway. My query was really about whether it was
possible to repair the tear, because one for the tip is not completely torn
off.

Regards

Rob