Dwayne Reid wrote:

> I originally considered just allowing the input of the MAX232 to be held LO
> while the switch was pressed but had thought that the PC would
> complain.  If that is not the case, then just make the pullup resistor on
> TX be 2 resistors in series with the switch shorting the midpoint to
> Gnd.  I'd still wait until the line was back HI before trying to talk to
> the PC, though.


Done and new version uploaded.

If the PIC sees a logic 0 on the TX line (RC6) then it goes into program
mode.

The input pin on the 232 chip has a 400K resistor to 5V. The PB
switch(link) shorts this line to ground via a 1K resistor.

I modified ROMzap.exe so that the serial port is only active during boot
programming. That way the PC should ignore the TX line at switch on.

--
Best regards

Tony

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