[Coco] re: Floppy drive/OS9 issue

[Joel Ewy]

Andrew <keeper63 at cox.net> wrote:>...
>With floppies in the drives, under RSDOS doing a DIR 0 starts up both 
>drives motors, but only steps the read-head on the first drive (reads 
>the disk OK), doing a DIR 1 starts both drive motors, but only steps
  >and reads the disk on the second added drive.
>
>Should both motors start? It doesn't seem to hurt, but it is a question.
    
  I believe that is a feature, not a bug.  :)

>Joel - you mention a patched form of RSDOS to read the other side? I 
>will also have to look around for the 3.5" floppy drives you mention 
>(with the jumpers) - I don't think I have any, but I might find some 
>somewhere (maybe goodwill).
    
  You haven't had a chance to see my just previous reply yet.  The  SWTPC web site referenced there shows how to use the unjumperable  kind.  Pretty cool.

>As far as the 5.25 drives are concerned: are the drive numbers not 
>connected in any way to the side numbers? That is DRIVE 0 (under >RSDOS) 
>refers to the first drive, and DRIVE 1 refers to the second - not to 
>sides 1 and 2 of the first drive? That is how I am now understanding it. 

  Right.  In my patched DECB, drive 0 is the first physical drive,  the first side.  Drive 1 is the second physical drive... Drive 2  is the first physical drive, the second side, etc.  I suppose  other versions could vary, but I would suspect they'd mostly follow the  same pattern.
    
  >Furthermore, Tandy only put two connectors (and left off teeth?) on the 
>cable - but a cable could be constructed with four connectors (to allow 
>up to four DSDD drives)?

  Right.  The CoCo can have 4 floppy drives on a single cable/controller.

  >If that is the case, then maybe it is just a matter of me making the 
>proper cables and configuring OS-9 properly (and/or patching DOS, or 
>using ADOS or something similar for RSDOS tasks)?
    
  That's what I think.
JCE