[Coco] CoCo 3 MMU test for all

[Roger Taylor]

Dudes and dudettes,

There's a trick to creating super long LOADM'able programs on a CoCo 
3 but it relies on every CoCo 3 giving the same results of the following test:

At the stock WIDTH 32 prompt, type:

?PEEK(65441)

Won't you please type the above command on your real CoCo 3 only (not 
an emulator), and post the results here?

It *should* hopefully yield 57 which is an MMU block #, ofcourse.  If 
it gives a reading of 11xxxxxx where the high two bits are set (or 
either of the 2 high bits) then a separate special LOADMable program 
would have to be created for that CoCo variation.  I could perhaps 
try to LOADM a patch right into Disk BASIC that would ignore bad 
readbacks while loading, but with all the types of DOSes out there, I 
doubt I will take that route.  The upper 2 bit statuses also might 
depend on the memory upgrade installed, etc.

I have already created a test copy of Jeweled which LOADMs the 32k 
backdrop graphics into MMU 48-51 before loading the program itself.

This is nothing new, but it *is* 2008 and my way of thinking is not 
like it was in 1985 or even 2005.  In a 512k CoCo 3 using the 
extended LOADM trick, huge extraordinary-for-a-CoCo 3 games with HQ 
sound effects and dithered graphics could be loaded in up to the size 
of a floppy disk, ofcourse.  A 128k-size .bin file containing the 
entire game contents?  I'll soon see.