[Coco] RE: [Color Computer] Looking for a Coco I 64k?

[Aaron Banerjee]

I've got an "F" board Coco I (actually, it's a "285" board, but you know
what I mean) with 64K and ECB 1.0 over Color Basic 1.1.  I use a program
to go into "All ram mode" (using a short ML program running in lower
memory that copies ROM into the upper 32K of ram -- uses $FF22 bit 2 to
switch memory type if I recall properly).  Seems to work quite nicely in
64K mode.  I'm not sure how any memory test in Color Basic 1.0 would know
or care whether or not your chips were 32K or 64K chips running being run
in 32K mode unless it deliberately did something Microsoftish such as
detect for them and crash just to irritate you.
   I have a "D" board that has been upgraded to 32K (ECB 1.1 over Color
Basic 1.0). I got it "recycled" from a college friend who went to bigger,
better machines years ago.  He'd done some stuff with the motherboard --
not just memory, it supports a Model I monitor...  Not that I'm planning
on doing this anytime in the near future, but what exactly has to be done
in order to run this thing in 64K mode (given that I could even find the
chips now)?
                   - Aaron Banerjee

p.s.  I seem to remember having to do some minor "surgery" on the "F"
board when I installed the 64K chips -- clipping a few capacitors if I
recall properly.

On Sun, 13 Nov 2005, Arthur Flexser wrote:

> The problem may not have been the motherboard per se, but rather the fact
> that the machine may have had Color Basic 1.0, whose memory test at startup did
> not allow for the possibility of 64K chips being in the machine.  The mods
> you did may have been something that forced the correct memory map via hardware.
> 
> Art