TC: int biosprint( int cmd, int byte, int port )

	- prototype in bios.h

	- outputs byte to port
	- port = 0 (LPT1)
		 1 (LPT2), etc...
	- cmd = 0 (print byte);
		1 (init printer port);
		2 (get LPT status)

	- returns status of (values are or'd flags):
	  0x01 time out (cmd=0 means output error)
	  0x08 I/O error
	  0x10 selected
	  0x20 out of paper
	  0x40 acknowledge
	  0x80 not busy

	- MS C uses _bios_printer()
	- see	INT 17