[Coco] OS9 RBF IT.TYP ????

[Willard Goosey]

On Fri, Jun 17, 2011 at 10:46:39PM -0400, gene heskett wrote:
> I believe that if set, placing a hexidecimal $20 in that byte, that is the 
> flag that says its a std coco floppy disk.

> But this a std that encompasses the 35T SS, 40T SS, 40T DS, and 80T DS or 
> SS formats.

> If this bit is not set (AND($20, IT.TYP)=$00, then it is up to your driver 
> to use other means to identify the disk.  

OK, I just tried reading a Disk BASIC disk from OS-9 (with DED)  by
setting the descriptor to typ=40 sid=1 cyl=23 vfy=1 sct=12 t0s=12 and
with it set to typ=60 .... and it worked both ways. $40 is non-os9
non-coco, while $60 is non-os9 coco.

> I fooled with that sort of thing using disk basic's discon routines, but 
> its 20+ years back up the log, so I don't recall a lot of details.

Yeah, I've done this in BASIC.  Playing nice with CCdisk is another
story. :-)

Willard
-- 
Willard Goosey  goosey at sdc.org
Socorro, New Mexico, USA
I search my heart and find Cimmeria, land of Darkness and the Night.
  -- R.E. Howard