HELP!!!! TRS-80 Mod III M/B NEEDED!!!!

From: Jason Willgruber <>
Date: Mon Dec 28 22:11:30 1998

>I would bet on the FDC still being OK, though. I've found the 1793 chip
>(the big 40 pin one) is very easy to zap. And you'll not test that without
>a working CPU board (the motor on/drive select logic is totally separate,
Probably. No paper clips had fallen into it, and no signs of external
damage. I really won't know if it's good or not 'till I get a new board.
Even if it is blown, I have a good, spare one.

>If you connect the CPU board to the PSU does the PSU still come on? Don't
>connect any other cables at this point. Do you have a scope or logic
>probe? If so, is there any activity on the Z80 pins?
It still turns on, but makes the CPU board seem more like a fog machine than
a computer, and it stinks up the house pretty bad.
I have a scope that someone was going to trash that appears to work, but I
don't have any cables but a couple of old multitester cables.
I doubt there would be any _useful_ activity on the Z80 pins. The chip is
basically melted. Most of the chips are like that. There's paper clips
permanantly fused to other parts of the board.

>The model 4 keyboard is the same as the model 3 keyboard but with 5 etra
>swtiches. They're both 8*8 matrices of swtiches with some positions
>unused. And the keys are in the same electrical position on the 2
>So a model 3 keyboard should work with a model 4 CPU board - you just
>won't have the control/caps/F1/F2/F3 keys. Model 3 software running on
>the 'Model 4' shouldn't mind that. Some model 4 software will be hard to
>use without those extra keys, though.

Anyone have a spare Model 4 board laying around anywhere??
Model III?

                 -Jason Willgruber
                  ICQ#: 1730318
Received on Mon Dec 28 1998 - 22:11:30 GMT

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