Re: TRS-80 Model III stopped responding

[rescue via cctalk]

On 2019-11-05 13:50, rescue wrote:

I haven't dug into this one yet, but I did get it booted in trsdos,
and the letter I on the keyboard wasn't working.

I shut it off, disconnected and removed the keyboard.  I desoldered
and removed the APLS switch, opened it up, cleaned up the carbon pad
and the contacts below it, reassembled it, tested it with my DVM, all
good to go.  I soldered it back into the keyboard, put the keyboard
back, powered on the system

I get CRT glow, system reset button will cause the floppy drive to
seek, but nothing on the screen, and pressing return after inserting
TRSDOS does not boot the drive (i.e. testing for a working core 
system

with no display).

I do need to test the power supplies and make sure I have not lost a
power rail on one of the two supplies.  I presume the one I need to
check is the one on the backside of the cpu board, as the one on the
side of the drive 'cage' powers the drives and the drive controller
board, and on power up and reset, the drives are motor on and
tracking, so I think that supply is at least providing +5/+12V.


Well, it is something with the supplies.  I tried the floppy power 
supply in place of the system one, and got a Cass? prompt !
Then I switched back, and got a Cass? prompt !  G !   I'm still 
digging maybe something failed and if I mount it back up it will 
stop working again (once the ground pads are grounded on the back of the 
supply ?).


I'm still hunting for the issue, it's either intermittent or something 
flaky with the power supply that fails when it is grounded.


Now to go off and find out which.

At least the mainboard didn't go 'poof'.

-- Curt



Seems odd that putting the keyboard back in resulted in a non working
system.  I unplugged it, same behavior with no keyboard plugged in.  
I

did not connect the kb connector off by one pin or one row so as
best as I can tall, Murphy has struck, and it isn't 'operator error'
:-).

Any tips from Model III experts welcome.

--  Curt

Re: Floppy drive (DSDD) DOS compatability woes (are these drives ok?)

[rescue via cctalk]

On 2019-11-05 13:45, rescue wrote:

Been away for some time from the mailing lists  getting back into
my classic gear again

I have two of these Qumetrack 542 drives.

While testing my 360K drive collection (8 drives I must be
slacking :-) ...), 2 worked, 4 had issue (resolved with a good head
cleaning), and 2 (both of the Qumetrack 542 drives (I have two of
them)) have mixed results.  My testing is on a Tandy 2500SX/33 using
the Tandy straight through cable and with the drives set do DS0.

I seem to have no issue with Dunfield's testfdc (using testfdc/x a:)
with these drives, doing SS and DD and getting 'pass' from testfdc.  
I
can also use his imagedisk program, go to the alignment section, and 
I

can track the drive properly up an down the disk it is just DOS
that can't seem to do it.

However, when I do a format a:, the drive will format through the 40
tracks, then instead of the heads returning to track 0 quickly, they
do these small stepping 'bursts' and DOS times out saying 
failure.
it probably would have worked if DOS would wait 10 seconds or more 
for

the drive to move to track 0.

I've never seen behavior like this.  I even tried an external power
supply in case the Tandy one wasn't up to driving the full height
floppy drive due to an aging marginal supply, but that didn't help
anything.

I've now also had one of them shut down the power supply (a shorted
tantalum cap I'm sure).

I've looked through the manual on the drive, I've tried the HM, HS,
and no jumper setting for stepper motor power, same results in all
cases.

I'm trying too determine if these drives are good.  I'm planning on
using them in a Tandy Model III that is upgraded internally to a 
Model
IV, but I feel these are basic drives and should work in DOS fine 
too.


I hope someone has a clue, as I'm tapped out of them currently.


Well, For reference... I figured it out.

Apparently the newer system (Tandy 2500SX/33 (386SX cpu)) has to fast 
of a step time.


I found a program called flopparm.com and teststep.com which are part 
of FPLKIT11.ZIP.


By using:

flopparm custom=10,15,15,8

I was then able to format a disk using DOS format.

I won't be using the drive on this system, and it will be being used 
likely in a TRS-80 Model III, so I'd imagine the older system won't be 
as aggressive on the timings as the 386SX is and it won't be an issue.  
So, both of my drives are confirmed good (well, after I replaced the 
shorted tantalum on one of them).


-- Curt




Thanks,

-- Curt

Modcomp Minicomputers Related - Preservation and Repair

[devin davison via cctalk]

Greeting. Its been a while since I have posted here. A while back I picked
up a large Modcomp classic minicomputer. Recently the person i picked the
computer up off of gave me a call to come and get many books and software,
among much more hardware. I have picked up hundreds of 9 track tapes. The
modcomp computer mainly ran the real time os MAX, however i also found many
tapes for a unix variant for the machine, that supported real time
operation as well.

I am trying to preserve things as best i can, I am set to pick up 3 more
machines, and among the tapes and documentation, Space is running out fast.

I am curious if any of this documentation has been archived already, if
not, i can get to scanning it in my free time. I have documentation on
everything. The hardware, the software, os code, everything.

The tapes are another issue all together. They were stored in probably the
worst possible place, in a area of extreme heat and humidity. Some are
musty, others look like new. I do not own a 9 track drive, i was thinking
it would be possible to get a 9 track drive with a scsi interface attached
to a more modern Linux system to dump the tapes to images. If anyone here
has suggestions on how to read off the tapes or where to find a drive, it
would be most helpful.

As a last resort, I have a 9 track drive that is attached to my pdp 11/34,
however i have not gotten that system into working order yet either, and am
unsure of if the drive is working yet.

I was also given an old emulator for the system,m written for linux. I have
not gotten the software to work yet. I need to be sure the software is not
still a licenced product and that the company is gone before i post it.
Perhaps someone here can find out why its not working. On a modern debian
system, it attempts to run and just exits, without any info as to whats
wrong.

Any help or suggestions on how to best preserve the documentation and
software is most appreciated. I am undecided on what to do with the
hardware yet. The hardware is fascinating, and there is a bunch of it,
however it is quite large and is taking up a large portion of space. The
hope is to at least get one running to test out and see if i decide to keep
a system after that.

--Devin D

Re: Andromeda disk controller diag/format disk found

[Jon Elson via cctalk]

On 11/05/2019 09:24 PM, allison via cctalk wrote:

On 11/5/19 10:08 PM, Jon Elson via cctalk wrote:

On 11/05/2019 12:11 PM, Al Kossow via cctalk wrote:

it would be good to get it archived.
I can do it if no one else volunteers



OK, you're on.  It is a 5.25 " disk in RX50 format, RT-11 file
structure, and bootable on both PDP-11 and uVAX-II.

Really?  I'd like to know how that was done as they are not the same.
You mean readable not bootable maybe?


I only did this on the uVAX-II, a LONG time ago, like 
1986-88 or so, when I got rid of the MFM disks.
So, my memory ir really faded.  But, I think there was a 
console procedure where you entered a couple
lines of commands to read in certain blocks from the disk 
and then run from some location, and
it would bring up the diag/utility from the floppy.  I'm 
pretty sure the procedure was in the manual,
which I think I sent to the guy who took the Andromeda 
controller.


Jon

Re: Andromeda disk controller diag/format disk found

[Paul Anderson via cctalk]

Where hey a blue board or handles? I think I have a few around here.

On Tue, Nov 5, 2019 at 11:10 AM Jon Elson via cctalk 
wrote:

> If anybody has an Andromeda Q-bus MFM hard drive/floppy
> controller, I have dug up the diags/utilities disk for it.
> This will boot from the floppy on an LSI-11 or MicroVAX-II
> and allow you to format drives and run diagnostics.
>
> Anybody need this?  I have no idea if the floppy is still
> readable, although it has been stored in good
> conditions.
>
> Jon
>

Re: Looking for DEC RA80 (or RM80, R80) service manual (EK-ORA80-SV or similar)

[Paul Anderson via cctalk]

My RA81 print set is REV A.

I can ship the RM80 pocket guide for scanning, but want it back. I'm
shipping some other things to a list member, and will see if he will scan
it. It is a copy, about 40 pages. EK-0RM80-001

On Tue, Oct 22, 2019 at 6:08 PM Antonio Carlini via cctalk <
cctalk@classiccmp.org> wrote:

> On 22/10/2019 04:38, Paul Anderson via cctalk wrote:
> > RA81 Maint Guide AA-M879B-TC
>
> Online
>
>
> > RA80 MG   AA-M186B-TC
>
>
> Online
>
> > RM80 POCKET SERV GUIDE  EK-0RM80-PG-001
>
> Seemingly not online anywhere ...
>
>
> > RA81 Field Maint print set  MP-01359?
>
>
> Rev A is online
>
>
> Antonio
>
>
> --
> Antonio Carlini
> anto...@acarlini.com
>
>

Re: Andromeda disk controller diag/format disk found

[allison via cctalk]

On 11/5/19 10:08 PM, Jon Elson via cctalk wrote:
> On 11/05/2019 12:11 PM, Al Kossow via cctalk wrote:
>> it would be good to get it archived.
>> I can do it if no one else volunteers
>>
>>
> OK, you're on.  It is a 5.25 " disk in RX50 format, RT-11 file
> structure, and bootable on both PDP-11 and uVAX-II.

Really?  I'd like to know how that was done as they are not the same.
You mean readable not bootable maybe?

Allison


> let me know where to send it.
> 
> Jon
> 
> 

Re: Andromeda disk controller diag/format disk found

[Jon Elson via cctalk]

On 11/05/2019 12:11 PM, Al Kossow via cctalk wrote:

it would be good to get it archived.
I can do it if no one else volunteers


OK, you're on.  It is a 5.25 " disk in RX50 format, RT-11 
file structure, and bootable on both PDP-11 and uVAX-II.


let me know where to send it.

Jon

Re: TRS-80 Model III and IV parts needed (keycaps, keyboard switch, ribbon cable, floppy drive parts)

[Fred Cisin via cctalk]

On Tue, 5 Nov 2019, rescue via cctalk wrote:

Looks like keycaps from a Model III, and possibly a model I would work.


Early model I will not fit, but the last of the model I keyboards might.
(There were several different keyboards used)

Re: Qume Qumetrack 542 track seeking issue

[Fred Cisin via cctalk]

The TRS80 step time is leisurely.

If the problem is the PC step time, it probably won't matter for TRS80 
use.

TRS-80 Model III stopped responding

[rescue via cctalk]

I haven't dug into this one yet, but I did get it booted in trsdos, and 
the letter I on the keyboard wasn't working.


I shut it off, disconnected and removed the keyboard.  I desoldered and 
removed the APLS switch, opened it up, cleaned up the carbon pad and the 
contacts below it, reassembled it, tested it with my DVM, all good to 
go.  I soldered it back into the keyboard, put the keyboard back, 
powered on the system


I get CRT glow, system reset button will cause the floppy drive to 
seek, but nothing on the screen, and pressing return after inserting 
TRSDOS does not boot the drive (i.e. testing for a working core system 
with no display).


I do need to test the power supplies and make sure I have not lost a 
power rail on one of the two supplies.  I presume the one I need to 
check is the one on the backside of the cpu board, as the one on the 
side of the drive 'cage' powers the drives and the drive controller 
board, and on power up and reset, the drives are motor on and tracking, 
so I think that supply is at least providing +5/+12V.


Seems odd that putting the keyboard back in resulted in a non working 
system.  I unplugged it, same behavior with no keyboard plugged in.  I 
did not connect the kb connector off by one pin or one row so as 
best as I can tall, Murphy has struck, and it isn't 'operator error' 
:-).


Any tips from Model III experts welcome.

--  Curt

Floppy drive (DSDD) DOS compatability woes (are these drives ok?)

[rescue via cctalk]

Been away for some time from the mailing lists  getting back into 
my classic gear again


I have two of these Qumetrack 542 drives.

While testing my 360K drive collection (8 drives I must be slacking 
:-) ...), 2 worked, 4 had issue (resolved with a good head cleaning), 
and 2 (both of the Qumetrack 542 drives (I have two of them)) have mixed 
results.  My testing is on a Tandy 2500SX/33 using the Tandy straight 
through cable and with the drives set do DS0.


I seem to have no issue with Dunfield's testfdc (using testfdc/x a:) 
with these drives, doing SS and DD and getting 'pass' from testfdc.  I 
can also use his imagedisk program, go to the alignment section, and I 
can track the drive properly up an down the disk it is just DOS that 
can't seem to do it.


However, when I do a format a:, the drive will format through the 40 
tracks, then instead of the heads returning to track 0 quickly, they do 
these small stepping 'bursts' and DOS times out saying failure. it 
probably would have worked if DOS would wait 10 seconds or more for the 
drive to move to track 0.


I've never seen behavior like this.  I even tried an external power 
supply in case the Tandy one wasn't up to driving the full height floppy 
drive due to an aging marginal supply, but that didn't help anything.


I've now also had one of them shut down the power supply (a shorted 
tantalum cap I'm sure).


I've looked through the manual on the drive, I've tried the HM, HS, and 
no jumper setting for stepper motor power, same results in all cases.


I'm trying too determine if these drives are good.  I'm planning on 
using them in a Tandy Model III that is upgraded internally to a Model 
IV, but I feel these are basic drives and should work in DOS fine too.


I hope someone has a clue, as I'm tapped out of them currently.

Thanks,

-- Curt

TRS-80 Model III and IV parts needed (keycaps, keyboard switch, ribbon cable, floppy drive parts)

[rescue via cctalk]

So, on this Model III I'm working on the following keycaps are missing:

1/! key
right shift key

Looks like keycaps from a Model III, and possibly a model I would work. 
Probably a Model IV keycap for 1/! would work, but I think the right 
shift key would be different between a Model III and Model IV.


I also need one of the ALPS switches as the '+' part of the stem is 
broken off.


In addition, on the drive (Texas Peripherals), there is a plastic 
component that screws onto the aluminum arm with the diskette retaining 
hub with 2 screws it then accepts two plastic pins that connect this 
piece to the drive door.  I am missing on of the plastic pins and the 
plastic piece is cracking.

Anyone have any of these parts kicking around.

On a Model III upgraded to a Model IV I have, the ribbon cable to the 
serial/com board has 'self destructed' as the glue failed, so once 
removed it could not be reconnected.  Interestingly the cable for the 
floppy controller did not deteriorate ?


Sadly on the upgraded Model III someone converted it to 3 drives, using 
an original full height drive for the 1st drive (at the bottom), and put 
2 HH drives in the top bay.  To make room for the eject control on the 
top drive, the upper case has been notched.  It would be nice to find an 
upper case for a Model III and do away with that notch or 
alternately an empty Model IV case (top and bottom).


Thanks to anyone with any TRS-80 'parts vault' that may have these 
parts available  It has been a long time since I have touched a 
Model I/III (last time was probably 1983 :-) ).  Looking forward to 
getting the 3 systems I have up and running (Model I with Expansion, 
Model III, and a Model III upgraded to a Model IV).


Thanks in advance,

-- Curt

Re: George Schmidt, Distinguished Lectures, January 16, 2020

[Tapley, Mark B. via cctalk]

All,
Southwest Research Institute will be hosting a talk in San Antonio, (Texas, 
USA) by one of the engineers involved in the Apollo navigation effort, George 
T. Schmidt. I understand he is aware of and very interested in the Apollo 
Guidance Computer work done by some of the folks on this list and others, but 
anyone who has not had a chance to talk to him might well be interested in 
attending, and would certainly be welcome.
The abstract and title for the talk are below, along with the URL for the IEEE 
distinguished lecturer website (which doesn’t say any more than I have copied 
below).
Anyone interested in attending, let me know and I’ll forward more details as I 
learn them. I expect the lecture will be around noon on Jan. 16 at SwRI, with a 
repeat at St. Mary’s University in the evening.

   Inside Apollo: Heroes, Rules and Lessons Learned in the Guidance, 
Navigation, and Control (GNC) System 
Development

This Abstract was written in March 2019 which is halfway between the 50th 
Anniversaries of Apollo 8 (Dec 1968) and Apollo 11 (July 1969).  Those 2 
flights were among the greatest explorations of mankind.  In 8, astronauts 
deliberately put themselves in orbit around the moon expecting the rocket 
engine to later fire and bring them home to Earth.  In 11, it was mankind’s 
first visit to the moon and Tranquility Base.  Movies, books, articles, and 
documentaries have covered the space race.  The author will give his thoughts 
based on 10 years inside the GNC program design, many hours in the Spacecraft 
Control room at Cape Kennedy monitoring GNC performance through liftoff, and 
then providing real-time mission support to NASA from MIT in Cambridge, MA.

that abstract appears on this website:

http://ieee-aess.org/education/distinguished-lecturer-and-tutorial-program#distinguished_lecturers-page-43

- Mark
210-522-6025 office
210-379-4635 cell

Re: Andromeda disk controller diag/format disk found

[Chris Zach via cctalk]

Agreed. I might have one of those controllers in my pile, information on 
them is now exceptionally rare, and without things like those disks one 
is sunk.


Also have an MTI ESDI Q Bus controller in my 11/73. It has its' own 
serial port that allows you to configure if you know the "HELLO" 
password, which is "MTI" (all caps). Without that bit of info it's 
useless


C


On 11/5/2019 1:11 PM, Al Kossow via cctalk wrote:

it would be good to get it archived.
I can do it if no one else volunteers

On 11/5/19 9:10 AM, Jon Elson via cctalk wrote:

If anybody has an Andromeda Q-bus MFM hard drive/floppy controller, I have dug 
up the diags/utilities disk for it.
This will boot from the floppy on an LSI-11 or MicroVAX-II and allow you to 
format drives and run diagnostics.

Anybody need this?  I have no idea if the floppy is still readable, although it 
has been stored in good
conditions.

Jon

Re: Andromeda disk controller diag/format disk found

[Al Kossow via cctalk]

it would be good to get it archived.
I can do it if no one else volunteers

On 11/5/19 9:10 AM, Jon Elson via cctalk wrote:
> If anybody has an Andromeda Q-bus MFM hard drive/floppy controller, I have 
> dug up the diags/utilities disk for it.
> This will boot from the floppy on an LSI-11 or MicroVAX-II and allow you to 
> format drives and run diagnostics.
> 
> Anybody need this?  I have no idea if the floppy is still readable, although 
> it has been stored in good
> conditions.
> 
> Jon

Andromeda disk controller diag/format disk found

[Jon Elson via cctalk]

If anybody has an Andromeda Q-bus MFM hard drive/floppy 
controller, I have dug up the diags/utilities disk for it.
This will boot from the floppy on an LSI-11 or MicroVAX-II 
and allow you to format drives and run diagnostics.


Anybody need this?  I have no idea if the floppy is still 
readable, although it has been stored in good

conditions.

Jon