INT 17 - PCIBM PC Magazine PCSpool - GET CONTROL BLOCK ADDRESS
	AH = C0h
	DX = printer port (0-3)
Return: ES:BX -> control block (see #00646)
SeeAlso: AH=C1h


Format of PCSpool control block:
Offset	Size	Description	(Table 00646)
 00h	WORD	printer number
 02h	WORD	address of printer status port
 04h	WORD	number of first record in queue
 06h	WORD	number of last record in queue
 08h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	characters already printed
 0Ch	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	number of characters remaining
 10h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	pointer to dequeue buffer
 14h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	previous count of characters printed
 18h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	number of clock ticks taken to print them
 1Ch	WORD	offset of next character to output
 1Eh	WORD	offset of next character to print
 20h	WORD	pointer to spooling queue record
 22h	BYTE	current spooling status
 23h	BYTE	current printer status:
		00h OK
		01h not ready
		02h paused with message
		03h paused
		04h initializing
		FEh non-existent port
		FFh not spooled
 24h	BYTE	current control record type
 25h	WORD	observed printer speed
 27h	WORD	characters to print per service
 29h	BYTE	01h if disk write needed
 2Ah	BYTE	01h if queued data should be flushed
 2Bh	BYTE	01h to update cps status