[Coco] coco 1 and 2 info needed

[Rogelio Perea]

On Tue Oct 21 2014, Josh Harper wrote:

I yave 2 questions
>
> will any of the chips in  the coco 1 work in the coco 2's
>
> I have a coco 3 that has most if not all its chip socketed  problem is
> with it  all I get  is a green screen nothing else   whats the most likely
> cause
>

Many of the chips are common: the 6821 PIAs, the 6847 VDG, the 6809 CPU and
the 6883 SAM. They can be used on either the CoCo 1 or 2. The RAM chips
though are another thing that needs to be looked upon closer before
committing a parts swap there.

The green screen as you describe usually means the CPU is blown, first
thing to replace with a known good one. If the CPU is soldered to the board
(most likely), it is a good time to install a socket on the computer main
board for it.


-- RP