Re: C64 PCB

From: Michał Pleban <>
Date: Fri, 19 Jul 2013 14:58:47 +0200
Message-ID: <>

Nicolas Welte wrote:

> I admit I didn't read the whole thread, but if you want to attach
> something to the three ROM sockets in a C64, you know that all data and
> address lines are the same on all sockets, and the difference is only in
> the three chip select lines? So it's enough to attach to one socket and
> pick up the remaining chip select lines from the other sockets with a
> wire, or maybe you can have a PCB with different holes for different ROM
> spacings for only these two signals.

Yes of course, you are correct (apart from the problem that on the SX-64
the chip select lines are different because the ROMs are in a different
order, and the narrow C64 boards have totally different ROM layout anyway).

The main reason I am not doing this is because I need to supply the
signals from ROM (address and data lines) to two different chips, and to
make matters worse, one is DIP32 and the other one is PLCC44. I tried
very hard to route the signals the way you said, but for the life of me
I was not able to do that - there were too many lines going across the
PCB and I was not able to route all of them successfully, especially
that also two TTL chips come into the picture and need to fit on the PCB

So I decided to make my life "easier", and I am supplying signals to the
DIP32 chip from the rightmost ROM socket, and to the PLCC44 from the
leftmost one. I agree this is not the most elegant way of doing this :-(


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Received on 2013-07-19 13:00:58

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