On Sat, 14 Jan 2012, Steve Nickolas wrote:
On Sat, 14 Jan 2012, Vladimir Ivanov wrote:On Sat, 14 Jan 2012, Steve Nickolas wrote:I've seen this title applied to something like what I've seen on a few disks. They'll be 13-sector, and have a bootstrap that boots on either a 13 or 16-sector drive.Anyone know how this could be pulled off, how one could create their own "universal" disk?One sector #0 in 13-sector format and one sector #0 in 16-sector format, both on track #0?Right. I'm just wondering how one would arrange that feat.
Easiest would be creating the track image in memory and writing the whole track at once with simple routine.
At least the 16-sector boot ROM can load more than one sector, so you would put few more 16-sector format sectors that hold code/tables that support 13-sector mode. The rest of the track/disk you make in 13-sector format.
If the 13-sector boot ROM has similar ability to load more than one sector initially, the complementary is valid, too.
This should reduce the effort to bootstrap additional sectors from the booting sector #0 so you can read the "alien" parts of the disk later.