On Apr 13, 2017, at 3:20 PM, Warner Losh via cctalk <cctalk at classiccmp.org> wrote: I?m pretty sure the PC100A takes the same board. I believe I have a 100A set up like that, but I?ll have to check when I get back (from vacation) in a week or so (unless you get a definitive answer before that). Meantime if you spot one of those boards, obviously it would be good to grab it; sounds like there are 100B users on-list who would be happy to give it a home if I?m wrong about it working in the 100A. Meantime, from my Rainbow Technical Manual copyright 1984 scan (ask, I have a fair number of these documents) which says it refers to model PC100A: Rainbow Memory Extension Option Installation Guide: EK-PCMKE-IN ?Two versions of the memory extension option are available: a 64 K byte option (part number PC1XX-AA) and a 192K byte option (part number PC1XX-AB). The memory option is installed in the J6 connector ? ? Both versions of the memory extension option use the same printed circuit board etch and the same type of 6kK x 1 bit memory chips. ? the 192K byte version contains twenty-seven 64K x 1 bit chips arranged as three 64K byte memory stacks. ... From my Rainbow Owner?s manual 1st ed. Sept 1983, Appx. C, Table C-1 ? 64K byte memory board option: PC1XX-AC 256K byte memory board option: PC1XX-AD 64K byte memory component kit (9 chips) PC1XX-AY 256K byte memory component kit (9 chips) PC1XX-AZ ? Hope this helps.

On Sat, Apr 15, 2017 at 9:56 AM, william degnan via cctalk <cctalk at classiccmp.org> wrote: I think that have what looks like the AD option, but it only brings my Rainbow 100A up to 256k. I bought the 100A recently based on a seller telling me it was a 100B. Grump. But at least its floppy controller and drive are in much better shape than my old ones, so I have some parts now. Just not sure what to do with them, but they may become spare parts, which I might be willing to part with. Not sure yet. Also, the boards themselves have numbers like 53xxxxxx and don't list the actual part. So googling for them often involves googling for that number because it's what sellers have easily available to them... Cool! I've had much luck since we talked last. I'm 5 sectors away from having all the disks read. Well, and understanding the encoding used on the boot disk to store the serial number in a difficult to replicate manner. At least I think that's what's going on. See http://bsdimp.blogspot.com/2017/04/rainbow-100-venix86r-disks-found.html for a few details. Unfortunately, the 5 sectors are on User disks 2 and 3, so are early in the series, which may make all the other readable disks useless. Not sure if there was compression at the time, so maybe it will just corrupt a few files. This is out of 16 400k disks, so it's a quite high percentage for them being so old. Btw, anybody know what might be on an "Enhanced BWS Supplementary disk"? A quick google search didn't bring up anything, but it's a Version 7 Unix. I'm hoping it's the compiler, in which case I may be able to reconstruct the missing material from the V7 sources. Warner