Int 61 Fn 01  - Banyan Vines - Check Service                               [N]

   AH = 01h
   AL = service ID (see #3122)

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

See Also: AH=00h,AH=02h"VINES",AH=03h"VINES"

(Table 3122)
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