[Coco] Multi drive controllers

[Darren A]

On Tue, Apr 3, 2012 at 8:54 PM, Bill   wrote:
> I know I can run the 5 1/4", as 2 drives (drive 0 and drive 2), and the 3
> 1/2" as a single sided drive (drive 1). I have no way to hack the other
> controller. Can the I/O address be changed by a POKE?
>

With two controllers in an MPI, you can switch between them by
changing which slot receives the SCS signal. For example, with the
controllers in slots 3 and 4, boot the CoCo with the MPI switch set to
4.  To access the drive(s) on the slot 3 controller:

POKE &HFF7F,&H32

To go back to the drives on the slot 4 controller:

POKE &HFF7F,&H33

Don't switch controllers when you have files open or you can corrupt
the disk (same rule as switching disks in a drive).

Darren