If a lpt ports (lpt1,lpt2,lpt3) or an hexadecimal address is specified the port is read and the read value is printed on the screen.
If also a value is specified the port is written with the specified value.
All the address and all the values are in the hexadecimal format.
The address of the lpt ports are detected using the BIOS informations at the memory address 408h.
portio lpt1 ff |
Clear all the parallel port data bits:
portio lpt1 0 |
Set all bit on the port 80h
portio 80 ff |
Set all the parallel port data bits in the config.sys:
device=c:\mame\portio.exe lpt1 ff |