Sends a character to the specified parallel printer interface port and returns the current status of the port.
Call with:
AH = 00H
AL = character
DX = printer number (0 = LPT1, 1 = LPT2, 2 = LPT3)
Returns:
AH = status
Bit Significance (if set)
0 printer timed-out
1 unused
2 unused
3 I/O error
4 printer selected
5 out of paper
6 printer acknowledge
7 printer not busy