INT 61 - Banyan VINES - CHECK SERVICE                                           
	AH = 01h
	AL = service ID (see #03451)
Return: AX = status
	    0000h installed
	    0001h not installed
	    0002h invalid ID
	    0003h invalid function
Note:	Only the offset part of the service pointer is checked for a nonzero
	  value
SeeAlso: AH=00h,AH=02h"VINES",AH=03h"VINES"


(Table 03451)
Values for VINES service ID:
 01h	communications
 02h	primary 3270 emulation
 03h	async terminal emulation
 04h	file deflection
 05h	print service control
 06h	get address of something
 07h	StreetTalk access service
 08h	environment
 09h	NETBIOS client service
 0Ah	secondary 3270 emulation
 0Bh	semaphore service
 0Ch	3270 emulation active status
 0Dh	T3270 keyboard interrupt simulator
 0Eh	enhanced 3270 service
 0Fh	comm Windows entry point
 10h	interface to NBNS