LPT ports, another proposal

Jim Hollenback jholly@hposl62.cup.hp.com
Thu, 9 Nov 1995 09:30:36 -0800

On Nov 8,  6:37pm, ken wolff wrote:
> Subject: LPT ports, another proposal
>      The program would have two "modes," old and new. Old mode continues to
>      work with existing CW keying circuits and would be the default. New
>      mode requires rework of the LPT connector circuit. In both cases LPT1
>      and LPT2 are nearly identical. Using this scheme you may enable CW
>      keying and DVK keying from either LPT1 or LPT2.

I like it!!

>      New mode Pinouts:
>      Antenna switch data:  2, 7, 8, 9 (LPT2 has band data for radio 2)
>      DVK F1-F4:            3, 4, 5, 6
>      DVK escape:           1     asserted for 100ms when escape pressed
>      PTT:                  16    asserted with PTT
>      CW key:               17    asserted on key down
>      Radio1/Radio2:        14   (on LPT2 this is audio select per AB6FO)

Might I suggest ...

New mode Pinout

	DVK escape 	     16
	PTT:		     17
	CW key		     1


Keeps more pins the same between the "modes".

It allows going to the new mode and not having to reconfigure
DVK's pins or interface circuitry much. Outboard boxes will need
a some changes on the transistor used for keying. The contest
card will need a trace cut and a pullup resistor. (I think, the
circuit details are from memory).


None that I can think of. Others?

Overall I like the proposal. Thanks for the opportunity to comment!

73, Jim, WA6SDM

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