[Coco] Coco 1 question

[Robert Gault]

Jeremy Michea wrote:
> Hi.
>
> I picked up a Coco 1 and with manuals and 6 rompaks for $10 at a charity garage sale today and I looked at the model number on the back - 26-3004A. I can't find much info on this particular model. How much memory would this unit have and what's the difference between it and the 26-3004?
>
> Thanks

The A series was, I think, the last of the Coco1 models.
The list of changes include:
easier to service PC boards
different shielding of the RAM and SWAM chips
transformer relocation
723 precision regulator; 5+ no longer adjustable but set by 1% resistors
-5v is a zener diode and resistor
heavier duty cassette relay powered by +12v
diode protection of some ICs
keyboard is conductive rubber, not mechanical
6822 PIA for keyboard instead of 6821; 6822 is open-collector
MC1372 modulator circuitry improved
RF bypassing on PC board now meets FCC requirements
RAM now uses 16K or 32K not 4K chips
jumpers indicate total RAM

Total memory could be 16K or 32K RAM plus 32K ROM. You won't know unless 
you open the case and look or enter PRINT MEM. With 32K RAM you will get 
22824.