Hello!
On Wed, 22 Sep 1999, Rogelio M. Serrnao wrote:
> I have an IBM PS2 77s with a 2.88 Mb disk drive. I dd'd GRUB stage1 and
> stage2 on a 1.44 Mb diskette. When I try to boot from that diskette, all I
> get is "Read Error".This does not happen with lilo. I intend to use GRUB
> to boot Mach4. I am trying to port Mach4 to the MCA bus.
This is already the second message within few days that confirms that the
BIOS values for floppies cannot be trusted.
The first time BIOS thought that the disk A: is 1.2M while it was a 1.44M
drive and a 1.44M diskette.
The result was that wrong sectors were read and stage2 just hung without
error messages.
This time BIOS apparently believes that all diskettes in 2.88M drives
should also be 2.88M
Stage1 tries to read sectors above 18 and gets an error.
As we all remember, the results of the "floppy probe" cannot be trusted
either. Some BIOS'es allow reading of higher sectors while booting from
CD-ROM's
Possible solutions:
1) Store the disk geometry in the stage1. Remove any geometry detection
from Stage1. Disable direct installing with "dd"
2) Store the disk geometry in the stage1. Remove the "floppy probe"
If the geometry is not stored ("dd" installation) use BIOS values.
3) Create yet another flavor of Stage1 that is not installable with "dd"
and stores the disk geometry.
Better ideas?
Pavel Roskin
