Re: SDS PROM-100 software

On Jul 30, 10:59 pm, lync...@xxxxxxxxx wrote:
Hi,

Does anyone have the original SD Systems PROM-100 software on disk?
If so, would you please send me a zipfile/tarball/attachments or
whatever of the contents of the disk(s)? Alternatively, post the
files to an archive or someplace else you'd like?

Thank you in advance.

Here is the back story if you are interested in why I am asking.
Otherwise, thank you and please stop reading now.

I recently repaired an SDS PROM-100 S-100 board and used it to copy a
2708 EPROM and to consistently read the content of another used 2708
EPROM. However, I am using the version of the software available in
the documentation which is intended for PROM only usage (ie, run from
a PROM as part of a monitor/debugger, I assume) so it does not contain
any file IO routines. I can use PROM08A and DDT as a work around but
it is highly clunky and it would sure be nice to have a more
completely supported PROM-100 software.

According to the documentation, there is a more complete version of
the PROM-100 software present on the original distribution disks which
I assume contains more thorough file IO and more complete
functionality.

The reason I need 2708 programmed is I am attempting to restore an
Ithaca Audio IA 1010B Z80 board which uses a 2708 EPROM. I built a
2708 EPROM simulator when I repaired my NorthStar Horizon ZPB-A2 CPU
card which worked great with Dave Dunfield's RAMless ROM monitor
(Thanks Dave!) . My plan is to use the RAMless ROM monitor to help
with the debugging once I get the IA 1010B CPU card working well
enough to use it. The IA 1010B has shown occasional signs of life
running my two serial IO test programs but has not consistently
behaved correctly. I think the main culprit is related to the broken
2708 components.

When I tried to use the 2708 simulator circuit (a DS1220Y with shim
socket) with the IA 1010B the 2708 simulator has been a disaster.
First the original IA 1010B used a weird and probably damaged 24 pin
socket. The IA 1010B CPU board only occasionally actually saw the
contents of the 2708 simulator leading to all sorts of problems and
inconsistent behaviour like the power on AutoJump never actually
finding any programs to run. Also, the simulator circuit's shim
socket broke about 50% of the time I tried to use it in the weird
socket and I do not really trust the part ever actually worked other
than maybe a few times.

I finally replaced the weird IA 1010B 24 pin socket with a more
standard one and then I find A4 line pin on the original socket wasn't
even attached or had a cold solder joint. It sort of was connected
when I checked with the VOM and oscilloscope but was suspiciously
hanging loose when I removed the plastic cover off the socket.

To make matters worse, once I finally got the replacement socket
installed, it turns out the new socket has slightly different height
than the one the NorthStar ZPB-A2 uses and the pins from the 2708
simulator circuit do not make any connection at all. ARGH!

In short, I decided the 2708 simulator is more trouble than it is
worth. To recover, I decided to get a real programmed 2708 working
and I fixed the SD Systems PROM-100 as a 2708 EPROM programmer. At
least so far, it is working and I have been able to make a backup copy
of the highly unique boot EPROM on my NorthStar Horizon. I have yet
to try to make a 2708 for the IA 1010B CPU board so I hope that works
out. We will see.

Thanks for reading and if you have a SD Systems PROM-100 original
distribution disks or copies, please send me a zipfile/tarball or post
the programs online someplace. I have already sent my version of the
PROM08.ASM program to the excellent bitsavers (Thanks Al!) and
invaluable Howard Harte's S-100 archive (Thanks Howard!).

Have a nice evening (or day, depending on where you live)

Andrew Lynch

Hi,
Just a quick follow up on this message. Sorry it is/was so long.

The SDS PROM-100 board is working great. The software in the
documentation is fine but it would be nice to be able to save the
contents of a 2708 EPROM to a file. I sort of can but using PROM08 to
dump the 2708 contents to a memory region and then using DDT to dump
the memory region contents over a terminal program. Not exactly the
smooth way to do it but at least I am capturing the contents of some
unique 2708 PROMs before they are lost forever.

Now that the SDS PROM-100 is working, I was able to burn my CPU serial
port test programs into a couple of EPROMs and now the IA 1010B CPU
card is working great. Being able to check continuity off the top of
the legs of the EPROM made it finally possible to proof out the
circuits and once that was done, the IA 1010B jumped to life and now
works reliably.

The serial card, on the other hand, has some problems I am finally
able to debug as well. The first CPU serial test program just sends
'0' (ASCII 30H) to the serial port as fast as possible so I can use it
to trace the circuits with the oscilloscope. That program works
great.

However, the next program is a "typewriter" program which echoes all
input like a typewriter. That program would not work for some reason
and I spent hours trying to figure out the problem. It responded to
input but sent usually two garbled but consistent characters for
everyone I typed in. Very strange.

Finally I found in the documentation and serial card schematic the
serial clock circuit attaches to the UART in two places. The same bit
rate signal is supposed to be on pins 40 and 17. On this board,
however, pins 40 contained the proper frequency signal for 9600 bps
but the pin 17 contained some other frequency which turns out to be
19.2 kbps signal. I am not sure what is the root problem but as a
temporary work around I reconfigured the serial card to input and
output at 19.2 kbps and now it works fine. Pin 17 does not appear to
attach to anything as far as I can tell. Weird.

Both CPU serial programs are now working so tomorrow I will install
the Dave Dunfield RAMless monitor and hopefully get that working too.

With the good news comes some bad news though. I managed to burn up
my bus extender card. Sometimes the card hangs up on the motherboard
connector when I plug it into the bus and it doesn't seat properly.
Generally speaking, no bad stuff comes of it since I catch it before
power up. Tonight I missed it and managed to blow up the 12V voltage
rectifier on the serial card. After some closer inspection, pins 2
and 52 were actually shorted together on the bus extenders female edge
connector. I think pin 52 wipers got over stressed somehow or wore
out and when I pushed the card into the slot they folded over and
touched the pin 2 wipers. Once I turned the power on, the trace
literally blew up on the extender card and then the 7812 let out the
magic blue smoke. That doesn't happen very often but when it does it
is disturbing.

Fortunately, I already have some replacement 7812's so repairing the
serial card was easy and apparently no harm done. There are a couple
of spare S-100 bus connectors in the scrap box to repair the bus
extender as well. Still, I hate blowing things up by accident.
Definitely am going to have to be more careful making sure the card is
plugged in properly from now on.

So that's the rest of the story. It all ended well. Hopefully
someone will find the original SDS PROM-100 software disks lying about
in their collections and we can update the S-100 archives with the
software.

Thanks!

Andrew Lynch

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