A printer port is basically an output only (in standard mode), so you probably can't read the value back. Check the voltages on the output pins, and see if they change.
I'm not sure about the adress, but these numbers (&H378) appeared on almost every website dealing with controling the paralel port in Qbasic. So I assumed it was the correct adres.
There is only one paralel port in the machine, one gameport (i think), and one com port.
Is the adres machine specific? or is it always the same? If it is machine specific, is there a way to retrieve the adres of the paralel port?
I'm not sure about the adress, but these numbers (&H378) appeared on almost every website dealing with controling the paralel port in Qbasic. So I assumed it was the correct adres.
There is only one paralel port in the machine, one gameport (i think), and one com port.
If booting is slow enough you could check easily what address is your port asigned to. Is one of the first screens you see if no OEM logo is displayed.
The parallel port adresses are stored by the bios on adresses:
0000:0408 LPT1's Base Address
0000:040A LPT2's Base Address
0000:040C LPT3's Base Address
in dos you can see what's on these adresses with the 'debug' tool..
Type 'Debug' after the promt and a '-' will appear. Then type d 0000:0408 and it will show the content of that adress.