[Coco] Re: Floppy drive/OS9 issue

[Joel Ewy]

I was just looking through a list of PEEKs & POKEs and found some  POKEs to modify RS-DOS for double-sided and 40t operation.  The  file can be found here:  
  http://doki-doki.net/~lamune/computers/coco/POKESIII.TXT
  and no doubt elsewhere.  In fact, I don't think I found it there  originally, but that's where Google found it.  Of course to make  the changes permanent you would have to burn a new EPROM.  But you  could put them in a little program.  Somebody (Robert Gault?) has  a program that lets you start your own code with the 'DOS' command.
  Copying directly:
  
  
For 6 Ms Step Rate POKE&HD7C0,0:POKE&HD613,&H50:PO
KE&HD816,&H14

For Double Sided Drives
POKE&HD89F,&H41:POKE&HD8A0,&H42

For 40 Tracks POKE&HC735,&H4E:POKE&HC7BB,&H4E
:POKE&HC7D0,&H4E POKE&HC7EF,&H4E:POKE&HCD26,&H4E
:POKE&HCEB5,&H4E POKE&HD44D,&H4E:POKE&HD29D,&H28
:POKE&HD65F,&H28 POKE&HD682,&H28:POKE&HD534,&H27
:POKE&HC75A,&H01
  JCE

Andrew <keeper63 at cox.net> wrote:  To all who answered my call for help, thank you.
...
Something that I am trying to understand, though: Joel, you said that 
RSDOS/Disk BASIC was never updated to use double-sided drives. I could 
have sworn, though, that with the FD502 disk system this was the case? I 
had a friend that had such a system (before I got my FD502 controller to 
replace my bad FD501 controller), and I could have sworn that with the 
drive he had you could put in a double-sided floppy, issue a DRIVE 1 
command, and read/write the other side? Maybe I am just not remembering 
things right? I am wondering if my memory is faulty, or if its a 
hardware/software issue?
...
-- Andrew