[Coco] Dual UART with FIFO Card for the CoCo

[Darren A]

On 6/15/10, sales at gimechip.com wrote:
>
>  I was going to design an interface that plugged into
> the cartridge port - this way the CoCo wouldn't even have to be opened and
> it would not matter which CoCo Model you have - the keyboard connector
> wouldn't matter. My thinking was that whenever the CoCo made an attempt to
> access the keyboard memory areas, the plug in cartridge would assert SLENB*
> disabling the internal devices and replacing them with the circuitry inside
> the keyboard interface cartridge. It seems plausible -
>

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If you use SLENB to disable PIA 0 whenever it is accessed, then you
also lose the ability to read the joystick fire buttons, control the
analog mux, and use the VSYNC and HSYNC PIA interrupts.

Darren