[Coco] MPI Detection in BASIC

[Boisy G. Pitre]

All,

I've come up with what I think is a foolproof way to detect a Multi-Pak 
in a Color Computer, and would like others to try it on their systems.

10 POKE &HFF7F,PEEK(&HFF7F) AND &H33
20 IF PEEK(&HFF7F) > &H33 THEN PRINT "NO MPI" ELSE PRINT "MPI"

The idea here is that when a CoCo doesn't have a MPI present, the value 
at &HFF7F always seems to be 126 or higher... since bits 7-6 and 3-2 
are ignored, then IF there is an MPI, we safely keep the values at bits 
5-4 and 1-0, while turning off the others when we POKE.  If the read 
comes back greater than &H33 (slot 4) then it's likely that there is no 
MPI.

I would be curious if this could be tried on a CoCo 1 and 2, as I don't 
have an MPI for mine.

Boisy