Universal XT BIOS for CBM PC40-III with large hard disks

There are various Commodore 80286 PCs. The ones I know: the PC30-III, PC35-III, PC40-III and PC45-III. All these systems use the PC40-III motherboard. […]

What they have in common is the fact that all these PCs only support HDDs up to 512 MB. This was a quite normal limit for those days and only servers were equipped with HDDs larger than 100 MB. The problem however is that HDDs smaller than 512 MB hardly can be found and HDDs larger than 512 MB won’t be recognised.

The solution is a piece of software to enable the PC to handle these larger HDDs: XTIDE Universal BIOS. It was originally meant to enable XTs to handle 16-bits IDE HDDs on their 8-bits ISA bus. But is has been expanded in such a way that ATs and larger PCs could benefit from its features as well.

Obscure solution for an obscure problem. I love it.


  1. 2015-10-28 2:23 am
  2. 2015-10-28 8:34 pm
  3. 2015-10-30 3:03 am