[Coco] Determining OS-9 Floppy Type

Phill Harvey-Smith afra at aurigae.demon.co.uk
Sun May 27 05:29:05 EDT 2007


Bob Devries wrote:
> The most relaible way to determine the type of an OS9 floppy is to read 
> LSN0 off the disk (the first sector on side 0 track 0), and decode the 
> first 3 bytes as the number of sectors, the next byte (offset $04) as 
> the number of sectors per track (always 18 for Coco OS9), and the byte 
> at offset $10 (16 decimal) of that sector, to tell you the number of 
> sides. In OS9 parlance, those are called DD.TOT, DD.TKS  and DD.FMT 
> respectively.
> 
> If *someone* can come up with a little (DOS?) routine to read that info, 
> it would make life easier when trying to make disk images of OS9 disks.

I have a little utility I wrote to do that when trying to copy the 
Dragon Beta floppies which are 16 sec/track/DD, except for track 0 which 
is 10 sec/track/SD, helped me modify the ddisk driver of Nitros to 
support this format.

Anyway, If anyone would find it usefull, they can have a copy of 
dumplsn0, (source as well), I can send it to the list or alternatly if 
anyone can provide me somewhere to upload it.

Dumplsn0 will run under either Nitros9 or OS9.

Cheers.

Phill.

-- 
Phill Harvey-Smith, Programmer, Hardware hacker, and general eccentric !

"You can twist perceptions, but reality won't budge" -- Rush.



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