[Coco] 4 drive system

[Bruce W. Calkins]

----- Original Message ----- 

From: "Robert Hermanek"

> I've never seen a 4 drive coco system.  Is it a single controller with 4 
> drives on one ribbon?  Is it a straight through ribbon with 4 drive 
> connectors?
>
> -RobertH
>
> --

====================

For most CoCo users maximum usability was 2 drives.  I have a 4 drive setup, 
but only 3 drives are online at a time.  To run a full 4 drive set on the 
CoCo you need to redirect the side select to the 4th drive select.  That 
took a jumper of some sort in the 4th drive or a twist in the cable.

The CoCo controller misused the side select line for the 4th drive select 
and had no connection to the normal 4th drive select.  The plus side to that 
was that with the proper pokes to Disk Basic one could use the back side of 
a double sided disk drive as another drive.  OS-9 could see it as a proper 
double sided drive.  However the lack of the 4th drive select limited OS-9 
systems to 3 drives.

Bruce W.