Re: [CAD_CAM_EDM_DRO] Wiring Problems

In a message dated 16-Nov-01 23:38:52 Central Standard Time,
timg@... writes:

> Anyone have a good test to verify the parallel port is
> OK? I would likely use a logic probe or even hook some LEDs from my pins to
> the +5 v line

Simply using "INP(888)" to see if "OUT 888,nnn" is then present does NOT
necessarily insure that the "buffered, if" parallel-port output is actually
"there".

I cobbled a "tester" with 8 LED's, each in series with a 1K R to ground, to
"look at" pins 2-9 (the "data byte" on the p. port). I also connected five
tiny push-buttons between pins 10-13, and 15, each to ground, to indicate
"inputs" by using INP(889). This can be "temporary" on a breadboard-socket,
or "permanent" on a home-brew PCB, with a short DB-25 cable/connector, as I
have done.

For "certainty", there really IS no other way! Jan Rowland


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