On Thu, Mar 13, 2003 at 08:46:41AM -0500, N9CO@aol.com wrote:
> Whenever the LPT port keying/ptt/paddle adapter is connected, the PTT is
> activated, and alternating Morse dots and dashes (di-dah-di-dah-di-dah...)
> are sent at whatever speed TR is set to. It seems that something is shorted
> in the LPT port on the PC. This same LPT adapter works fine on my regular
> DOS PC. It works fine on my LINUX box, too.
>
7.1.5 The paddle interface just sends dits or dit-dah-dit-dah.
Some computers do not have a pull-up resistor on the parallel port
inputs. It might be necessary to provide pull-ups to +5 Volts on the
two inputs used by the paddle. This can be done by connecting a 10K
resistor from each paddle input to pin 14 on the parallel port
connector. Pin 14 is held at +5 volts and will pull the inputs up to a
high logic level when the paddle input is open.
--
George Fremin III - K5TR
geoiii@kkn.net
http://www.kkn.net/~k5tr
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