[Coco] FHL Color Flex

[john dumas]

On 4/7/2013 10:17 AM, Frank Swygert wrote:
> So track 0 is different, believed to be single density.  That can 
> cause problems for creating an emulator DSK image file. So WHY is 
> track 0 SD, 
Years ago, I heard an explanation that they wanted any FLEX system - even
single density - to be able to read any FLEX diskette directory. Since 
the directory
is on trk0, you could at least know what was on the diskette, even if you
could not read the other (double density) tracks.......

Not sure that I entirely agree with that logic, but it does make a sort 
of sense given
the state of the art at the time.
> and what part of the code reads/uses it? 
Boot, SIR, Directory.
> The solution may be to solve that riddle and modify the code so that 
> it no longer needs the SD track.
That would be OK for reading .DSK files, probably. If reading a real 
diskette....Fail, no boot. no SIR,
no Directory.......

> I suspect it's a boot program of some kind. FLEX (like OS-9) was 
> likely developed on an old system that used SD disks as standard, then 
> when DD disks became the norm everything was changed except the boot 
> track. 
Exactly. For the "reason"  I quoted above.

cheers,
johnd