ast@cs.vu.nl (Andy Tanenbaum) (11/19/88)
MINIX has now been tried on the PS/2 models 30 and 50. It works on the 30 and not on the 50. We have no idea why. The point of this message is to see if we can put our collective heads together and figure out why. Some facts. When booting MINIX on the Model 50, it takes 45 seconds for the initial menu to come up. Clearly something is wrong. The diskettes used were 3.5 inch 720K diskettes. The model 50 normally uses 1.44M diskettes, but is supposed to work with 720K diskettes. Perhaps something is wrong with bootblok.s. That first tries 1.2M, then 720K. But it uses the BIOS, so it should work. When it finally loads, the fsck option 'f' works fine. This suggests that it did load. However when 'u' or 'd' are hit, it just dies instantly. Since the hard disk driver is bios_wini, it ought to work. Furthermore, the hard disk driver does nothing until somebody calls it, so it doesn't even try to initialize itself. What it does do is find out if it has a mono or color screen, and then write directly to the video ram at 0xB0000 or 0x B80000. It assumes there is a 6845 in there. Maybe this is false. Other than that, I can't see why it doesn't work. After all, it works fine on the AT, which, like the model 50, is a 80286 chip. I don't have a PS/2 around, so I can't debug it. This is clearly a big pain. I would greatly appreciate it if we could try to brainstorm this in the newsgroup. Better yet, if anyone has access to a model 50 and the time to work on it using 1.3 + the posting of bios_wini.c (and changes to glo.h etc.) that would be great. Andy Tanenbaum (ast@cs.vu.nl)