+5V

Thanks to all who responded. Below is a summary of various
alternatives:

1. Al Schoepp: get +5V from keyboard connector/gameport

2. Doug Fortune: +5V Wall Transformer + tie ground to pin 18 (but +5V
from PC still better)

3. Dan Mauch: Avoid +5V, use G210/G340
replace optoisolator with adaptor board

4. Bob Campbell/Dean: +5V supply on breakout board and tie ground to
DB25 groundpins.

However, if the serial port is already used to connect to DeskNC for
windows blackbox, and the only available option is a USB port, is it
safe to tap the +5V from pin 4 of the USB port?

Thanks in advance

Meneer