stevel@eleazar.dartmouth.edu (Steve Ligett) (07/27/88)
Last year, noticing that IBM used SIMMs for the PS/2 model 50 memory, I thought that it might be a snap to upgrade the motherboard to 2 megabytes. I mean, hadn't they put that 640k upgrade route in all XTs? (Yes, and they had a 64k downgrade route wired in there too, my unconscious reminds me.) A brief look at the Technical Ref gave me some worry, but I bought some 1 meg by 9 SIMMs anyway, to try the upgrade. It didn't work. If I had free time, I might be able to cobble something up that would work, but at this point I'd have to spend some time looking at the POST to guess if it would recognize the memory. sigh. Also, I bought the Rodime "Double Play" disk drive upgrade for the 50. The drive is faster and bigger, (30 ms seek, and 44 MB), but the installation instructions were not well thought out, and the thing isn't well integrated with the PS/2 -- you have to run special software to partition it, and use a driver w DOS, and the PS/2 configuration program doesn't recognize the disk. If you want more detail on this, drop me a note and I'll write more when I'm more caught up. Finally, has anyone done up a schematic of the motherboard? I'd like to try to "zero wait-state" it sometime. Steve Ligett steve.ligett@dartmouth.edu or (decvax harvard ihnp4 linus)!dartvax!steve.ligett