>The 16C54's lack of interrupts does not eliminate the problem at the PIC's

cut cut...

>all its time for the next 2ms outputting video data.

Well, lets agree to disagree, I still don't see that any of the above
necessitates bidirectional lines os esoteric protocols.
>
>> Speaking of bidirectional lines, which lines of a PC printer port are
>> defined as neccessarily bidirectional? Hmm?
>
>/ACK, /Strobe, /Autofeed, /Reset, and the other output control signal are
>all open-collector with feedback inputs.

I'm not sure enough to argue and what the defined standard is but in
practice different systems are used and what works on many cards may fail on
others just when you were sure of universal compatibility. |I  have been
caught with an eprom emulator  and a 8748/9 burner, both published in US
mags via DIY in hong kong..

>If you leave interrupt windows between bits, that will impose a maximum
cut cut......
>useable in all and which could therefore be coded once and re-used whenever
>such a protocol was needed.

As long as the technical merrits are on the table I'm not going to argue
endlessly on philosophical design preferences. Personally, I believe in
tailor made optimal solutions but I realize it a personal choice.
>
>Ah, but the Parallax programmer doesn't exactly have to do a whole lot while
>it's talking to the PC.  In some applications, however, the PIC may be doing
>extremely time-critical things [analog input being the most likely in many
>cases, though video output or analog PWM'ing would also qualify] and be
>unable to afford the time it would take to monitor for PC communication.

John, whatever....   but I still fail to see how you have adaquately
promoted  your system as been practical. Purely from a technical point, the
issue is far from resolved.

I know what works for me and all the senarios you forwarded I am sure I can
solved in simpler ways than you prepose. As I said before, maybe the whole
matter is philosophical, but regardless of, I don't feel comfortable
continuing as others are paying to down load this and it hasn't appeared to
have wide spread appeal (interestingly!).

I wish you good luck with your system and I'll move on.

Regards

Jim

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