Yup Andrew, I'm sure it's Multi-Bus 1 now because the 12" by 6-3/4" card spec (thanks again gerritv) perfectly matches the cards, and they also have the same extraction ears on the outer corners. Everything matches.
Now for the fun. This machine was bought used maybe 8 years ago, and was hooked up, but failed to b e useful because " it crashed periodically, wouldn't retain machine settings, and had small program capacity." They had given up on it -- a white elephant taking up lots of space.
Well I was nosing around yesterday, and asked about the history of the thing, then asked if I could have a look inside the control cabinet. They unlocked it and basically said "knock yourself out". I love a challenge, as I'm sure 100% of you guys all do, so I just said, heh, just curious.
First card I pulled, and wrote you about turned out to be packed with 32K x 8 SRAM chips, and guess what....... two "vintage" rechargeable batts.The board was also only half populated with SRAM chips -- sockets for the rest available.
You can guess what I'm thinking about the above symptoms, and about how difficult this machine is going to be to "fix".
Thank goodness I built my first computer in 1981 -- an LNW-80 from bare boards, soldering in all the IC's, caps, resistors, xtal, programming the EPROM, etc.
So much fun knowing these "mysteries" around today's bright but head scratching black box engineers. And nice to see the old discreet parts with familiar numbers in all their rows of K sized memory chips. Actually back then, I longed for static RAMS in these quantities -- stuck by circumstances with DRAM. I'm working with top of the line stuff here -- from back then. Cool!
![:thumbup:](https://madmodder.net/Smileys/default/happy0034.gif)