I am trying to capture an input with a status pin on the standard IBM parallel port.
I looks like all the status pins are set high default when there's no external voltage source connected. If I measure the voltage drop across pin 13 (status 4) and pin 25 (ground) I get 5,1 V. Shouldn't it be zero?
I am using FreeBSD and if I read the value of the status pins with nothing connected I get Status: 0x7f Nothing happens if I connect a 5 V voltage source to pin 13 and pin 25.
If I short circuit pin 13 and pin 25 I get Status: 0x6f
Isn't it supposed to be the other way around or am I doing something wrong?