INS4004D in Pro-Log M900 PROM Programmer
hilpert at cs.ubc.ca
Sun Aug 26 14:09:31 CDT 2007
Sellam Ismail wrote:
> Not to cause a run on Pro-Log PROM programmers, but the M900 at least has
> an INS4004D microprocessor (National Semiconductor 4004 second source) at
> its heart.
> I only found out because I'm trying to figure out why this M900 isn't
> working and opened it. I re-seated all the chips, hoping for a quick fix,
> but no go.
> Are there any known, simple to fix faults on these? It powers up, power
> supply is good, no output on the LEDs other than transient voltage spikes
> on startup causing individual elements to momentarily light. Otherwise,
> no activity.
I've had a few problems with mine, mostly failing semiconductors, all of which
have been unusual and difficult to replace/substitute, although I was quite
pleased when I found the 4004 inside.
I presume you have the manual, which has the schematic and a listing of the
base code firmware.
I suppose it's conceivable the 1702 firmware EPROMS are losing their contents.
I have taken dumps of the contents of the ones in mine, if of interest. There
is a hitch though: various options come on additional firmware 1702s, and some
experiments with mine suggested that the base code does not auto-detect the
options, rather it appears (one of?) the base code EPROMS is tailored for the
particular firmware options installed, so the dumps I have may be valid only
for the option set I have. Similarly, if someone has pulled one of the option
ROMS in yours, the unit probably won't work. (Is this a new toy or something
you know was working? Also, out of interest, which personality module do you
have plugged in?)
If you haven't used the unit before, you do have to press one of the
LIST/DUP/VER/COPY keys initially to get anything to display on the hex LEDs
(initially blank on power-up), although I expect you've banged on all the keys already.
IIRC, some of the communication adapters if plugged in (serial¶llel D
plugs) may cause the unit to appear hung.
If all the power supplies levels are OK I suppose the next thing would be to
'scope for multiplex/keyboard scan activity to see if the processor/firmware
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