PORTIBM PC Portable (uses same BIOS as XT) 063E-063F - WINTEL.VXD - API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running.  Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes.
Note:	the WinTel remote-control program uses these two virtualized ports
	  as an API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running.  Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes. between it main application HOST.EXE and the WINTEL.VXD
	  driver
Index:	installation check;WinTel

063E  R-  always reads 42h if WinTel.VXD is loaded (installation check)
063E  -W  simulate keystroke to current Windows VMsee Virtual Machine (scan code as it would
		  be read from keyboard, including make/break in bit 7)
		  (see also INT 09)
063F  RW  watchdog/scratchpad (see #P0916)


Bitfields for WimTel watchdog/scratchpad byte:
Bit(s)	Description	(Table P0916)
 7-4	scratchpad; HOST.EXE uses as follows:
	bit 7: physical connection is active
	bit 6: sending file
	bit 5: receiving file
	bit 4: session is active
 1	retrigger watchdog (write 03h to PORTIBM PC Portable (uses same BIOS as XT) 063Fh to avoid reboot)
 0	enable watchdog (PCIBM PC is rebooted if watchdog not retriggered every 20s)