I have an HP 9872 plotter that just died. According to the internal self
test (very nice!)
one of the bib (MOS to TTL) drivers has failed. A scope shows one data
line not moving also.
The HP part number is 1820-1584. I can't find a cross reference on the
web for it. Does anyone
know if there's an equivalent chip? It's a 20 pin dip.
I know the chip well, it turns up in a lot of HP devices of that date. I
am pretty sure there are qite a few i nthe HP9825 and 9845 machines, for
I know of no replacement. It was never corss-referenced in Bench Briefs
to my knowledge. Evey one I ahev see had had an HP logo on the package.
And the MOS side is somewhat odd votlage levels.
Your best bet, I think, is to try to find soemthing else that uses them
(look at HP9825, HP9845, boards and soem of the peripehral modules for
said machines) and see if you can get a dead board to strip the ICs from.