INT 17 - PRINTER - WRITE CHARACTER                                              
	AH = 00h
	AL = character to write
	DX = printer number (00h-02h)
Return: AH = printer status (see #00631)
Note:	Under PhysTechSoft's PTS ROM-DOS the parallel port can also be
	  accessed as COM5.
BUGS:	Some print spoolers trash the BX register on return.
	Some original IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. BIOSes set more than one printer status bits at
	  a time, while only one of them is correct.
SeeAlso: AH=02h,AH=84h"AX",AX=6F02h,AH=F1h,INT 16/AX=FFE3h,INT 1A/AH=11h"NEC"
SeeAlso: INT 4B/AH=00h,PORTIBM PC Portable (uses same BIOS as XT) 0278h"PRINTER",MEM 0040h:0008h,MEM 0040h:0078h


Bitfields for printer status:
Bit(s)	Description	(Table 00631)
 7	not busy
 6	acknowledge
 5	out of paper
 4	selected
 3	I/O error
 2-1	unused
 0	timeout
Notes:	If both, bit 5 "out of paper" and 4 "selected" are set, the MS-DOS/
	  PCIBM PC DOS kernel assumes that no printer is attached.
	for Tandy 2000, bit 7 indicates printer-busy when set rather than clear