INT 1A - Disk Spool II v4.0x - SPOOL(Simultaneous Peripheral Operation OnLine)  The process of performing output to a slow peripheral such as a printer while other tasks continue running on the CPU.  This term dates back to mainframe days before the invention of timesharing. EXISTING FILE
	AX = E401h
	ES:BX -> ASCIZA NUL-terminated ASCII string.	The ASCIZ string "ABC" consists of the four bytes 41h, 42h, 43h, and 00h.  Unless otherwise specified, maximum lengths given in the interrupt list do not include the terminating NUL. filename (max 32 chars)
	CL = printer port (01h COM1, 02h COM2, 05h LPT1, 06h LPT2)
Return: AH = status
	    00h successful
	    FFh failed
Note:	this function is also supported by Vertisoft's Emulaser utility ELSPL,
	  as that is a licensed version of Disk Spool II
SeeAlso: AH=E1h,AX=E302h,AX=E402h