svn commit: r194241 - head/lib/libdisk

[John Baldwin]

On Tuesday 16 June 2009 12:45:21 pm Marcel Moolenaar wrote:
> 
> On Jun 15, 2009, at 11:33 PM, Ulf Lilleengen wrote:
> >
> > I'm a bit confused now :)
> 
> What bde@ said is that 255 is the max number of heads that is
> supported everywhere. 256 may work but is not always
> supported. Some web page states that DOS and Windows 95/98
> don't support 256 heads(1).
> 
> (1) http://web.inter.nl.net/hcc/J.Steunebrink/bioslim.htm#4GB

There was a bug in the BIOS for 2940 Adaptec SCSI controllers IIRC where it 
would actually hit an internal divide-by-zero bug if it encountered an MBR 
table with an entry where the head was 255 (it did a + 1 to get the number of 
heads so it could work out C/H/S the MBR was expecting).

-- 
John Baldwin