[ILUG] Hardware Issue

[Niall O Broin]

On 26 Aug 2004, at 17:30, Lisa Muir wrote:

> I can't get the newer machine to even attempt to boot from the old
> disk. I've checked and double checked the jumpering and checked and
> double checked the bios. The hardisk is a seagate, and the bios
> autotypes it perfectly.

And this may well be the root of your problem. IDE drives consist of a 
bunch of sectors, which are arranged in cylinders, which are accessed 
by a number of heads. For nasty hyster(istor)ical reasons, the drive 
often has to lie to the BIOS about its geometry, and the drive can 
quite happily (pretend to) be any number of different geometries.

For example, let's assume that one hypothetical drive has 1000000 
sectors. The drive might tell the BIOS that it has 10 heads, with 100 
sectors per cylinder, and 1000 cylinders, or it might use any other 
combination of numbers whose product is 1000000. This generally doesn't 
bother Linux at all, as it uses the physical layout of the drive, but 
where it can make a difference is in booting, which is BIOS controlled.

It is quite likely that the two different BIOSes make different 
decisions about the geometry of the drive, and hence there are booting 
problems.

Hopefully, it's not too late for you to put the old drive back in the 
old machine. Having done that, take a note of the geometry of the 
drive, as autodetected by the BIOS (or if it wasn't done by 
autodetection, note the values used for cylinders, heads and sectors).

Replace the old drive in the new box, and then instead of autotyping, 
set the drive geometry manually to the values from the old PC and you 
may be off to the races - or not, in which case, I can't help you 
farther :-(


Niall