[Coco] RE: [Color Computer] CoCo 2 questions.

[Glen VanDenBiggelaar]

Hi, Phill,
What Model number is it?
I have the service manual the 3026,3027. Upgrade instructions are on my 
website (www.coco.8bit-micro.com) on the CoCo 2 page. yes, You want to 
replace the chips with 4164 with 200 NS or better time (a good example is 
TMM4164AP-20 ). I will look closer at the scematics for the other chips you 
mentioned.
-Hope this helps abit,
-Glen


>Just got myself a cheap, (£4.99) CoCo 2 off ebay, not working at the
>moment, but I intend to fix that :) I have a couple of questions :
>
>1) It seems very different from the CoCo 1, much more compact, and seems
>   to have some different chips. Does anyone know where I can get a
>circuit sheet for this, I have the CoCo 1 tech ref, but this seems to
>different.
>
>2) There are a couple of chips with numbers I don't recognise they are :
>
>HD61J204P / TCC1000, a 28 pin chip on the bottom left of the board.
>
>SC7331P, a 40 pin chip in the top middle of the board, next to the 6821,
>this seems to be connected to the keyboard, so I assume it's a PIA, but
>that's a number I don't recognise.
>
>3) There seem to be some wire links to select between 16K and 64K rams,
>assuming that I can get some 64K, what type does it need (41464s at a
>guess) ?
>
>Also the machine seems to have a 74LS785, rather than a 74LS783, I have
>tested this in my Dragon test board and it works ok, but wondered what
>the difference was ?
>
>Thanks.
>
>Phill.
>
>
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>
>
>
>
>
>




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