Re: reading vic20 or c64 column

Date: Tue, 30 Jun 2015 16:09:39 +0200
Message-ID: <>
On 2015-06-30 10:41, Marko Mäkelä wrote:

> Hmm, this seems the opposite route: using a modern keyboard with old
> hardware. I thought that Jim Brain already has something for this
> application. AFAIU he is controlling a programmable switch matrix with a
> microcontroller.

I have (somewhere - one of those little things that I am unable to find
after moving stuff around) an implementation based on an Atmel and an
analogue cross point switch IC. But I am quite sure it isn't Jim's work.
So there is at least one more in the wild.

> If you know which way the software is reading the keyboard matrix, you
> can theoretically replace it with something simpler, such as essentially
> a RAM that connects address lines to columns and data lines to rows, or
> vice versa. Instead of address and data lines, you might even use the
> GPIO lines of a fast enough microcontroller, and maybe implement Pin
> Change Interrupt on those lines.

AFAIR all the earlier projects of this type kept failing one way or
another. The only one that I can eventually confirm working well was the
one with analogue switch IC.


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Received on 2015-06-30 15:00:07

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