[Coco] CoCo 3 I/O map

[Robert Gault]

Willard Goosey wrote:
> Any additions?  Corrections?
>

Here are a few.
$FF00   bit 7 joystick comparison input
$FF01   bit 3 MUX sel-1
$FF03   bit 3 MUX sel-2
$FF40-$FF57  Disto Disk controller and mini expansion bus
              Use in several Disto products including SC-II no-halt controller &
              MProm adapter
$FF58-$FF5F  SC II alternate no-halt registers
$FF74-$FF77  Ken-Ton SCSI hard drive interface; including an RTC if present
$FFC0-$FFC4  Smartwatch DS1216