In high quality parallel cables, each of the databit wires is shielded, 8 ground connections eases this, now each shield has a pin to be connected to, in stead of soldering 8 shield's to 1 pin (that would be messy)...
im on about 18 to 25 are ground pins yes but the computer reads from them.
the un insulated wire is the ground you use if you dont want the computer to read from it
i created a program in c++ that reads from all pins i put a logic level through pin 20 and it showed up i think those pins are seperate ground pins for each data wire
pins 18-25 ARE ground pins and should all be connected together.
Without connecting the ground pins to proper ground, the parallel port device you are making won't work well.
I believe this is a case to say 'oh my god :roll: '
well, whatever you say doc, i'm not going to argue...
(last tip, as i said above ,measure them, they are all connected together, what conclusion do you get out of that ? - also try measuring between your pc's case and eighter of pins 18 -25 , also connected together)