[Coco] [CoCo] The Trials to disable RS232 Status

Darren A mechacoco at gmail.com
Sun Oct 1 11:44:13 EDT 2017


On Sun, Oct 1, 2017 at 2:19 AM, Arthur Flexser wrote:

> Another method of bypassing the RS232 status check is these pokes:
>
> POKE &HFF23,&H30: POKE&HFF22,&HF9: POKE&HFF23, &H34
>
> This will work on any model CoCo, does not depend on what ROM version
> exists in the machine, and does not require copying ROM to RAM.
>
> I works by using the PIA's data direction register to change the relevant
> status bit in $FF22 from an input to an output, so that the RS232 status is
> always seen as "ready" by Basic.
>


But wouldn't that be potentially damaging to the CoCo?  You are configuring
the PIA pin to be an output driving the line low, while the SALT chip (or
OpAmp) will be driving it high, essentially creating a short-circuit.


- Darren


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