Schamatics for HP Plotter DraftPro EXL / DXL or 17573A HP 1Mb expansion card

[gurth]

Hello, new user here :wave:

I have a "thing" for pen plotters and have in my garage a HP DraftPro EXL A0 machine with an RS232 port on the rear. Next to that is an expansion port for a memory expansion.

The expansion cards come in either 1Mb or 2Mb I believe, but are like hens teeth to find. I have been wondering if I could make my own card, if I could get a hand of some schematics of either the expansion bus or of an actual card.

I am slowly learning electronic with an oscilisope and breadboards, have played with KiCAD too. I realise it my take me a year or so....!

The HP part number for the 1Mb expansion card is 17573A.

Any ideas, pointers or suggestions would be warmly received.

Gareth