jnall%FSU.BITNET@cornellc.cit.cornell.edu (John Nall 904-644-5241) (05/20/89)
HELP! I'm back on this project of trying to get Minix 1.4a to compile under Turbo C 2.0, and have about decided that the differences between Minix 1.3 and 1.4a are not the problem. The problem seems to be that the disks produced with "build" under Turbo C and the disks produced by "build" under Minix are written differently. Comparing them, the first 9 sectors (this is a 360K disk) are the same (i.e., sectors 0-8). But sector 9 on the Minix disk is the same as sector 18 on the Turbo C produced disk. Since the part of bootblok which reads the sectors in has not changed between Minix and the Turbo C version, there is an obvious problem. Sure enough, trying to boot a disk made under Turbo C bombs. The bootblok program reads the stuff in, since it doesn't care what is in the sectors. But when it jumps to fsck at the end, there is garbage there. Does this ring a bell with anyone? Am I overlooking anything? Is anyone using the Turbo C material which Deborah Mullen sent out? If so, and if it is working, I would be grateful for some advice. I'm doing this on an AT, but using 360K disks. Have tried it on both drives (and on two different AT's). Stepping through bootblok on the load, it appears to know that it has a PC disk (i.e., it uses pc sector-vector, rather than the at one). John Nall Computer Science Department Florida State University Tallahassee, Florida 32306 904-644-7043 (nall@nu.cs.fsu.edu -- Internet/Arpa) (jnall@rai.fsu.edu -- Bitnet)
Dickson@pco-multics.hbi.honeywell.com (Paul Dickson) (05/20/89)
The problem is not with Turbo C, but with MS-DOS. If the format
information is unavailble for a disk in a drive, the MS-DOS assumes that
it is the original MS-DOS format for PCs, which was single sided. The
only way around this it either rewrite build to use BIOS calls or always
reformat the disk before writing a MINIX image. Fcrmatting doesn't take
much time, so no one has fixed build.
Kevin and I, at one time, had a program that would write the first
couple of sectors on to the floppy so we wouldn't have to always
reformat the disk to get the info on sector one. I don't remember why
we stopped doing this...
-Paul Dickson
taurus!dickson @ asuvax.asu.edu