and if you only needed a few milliamps at 5V, you could tie together a few lines (ideally with isolating diodes, but in practice, total bridging worked fine) an

and if you only needed a few milliamps at 5V, you could tie together a few lines (ideally with isolating diodes, but in practice, total bridging worked fine) and get enough power to run your circuit. I had tiny i2c eeprom programmers built into DB25 hoods that just worked being plugged into a parallel port.