)
Call protocol support entry point with:
	BX = function number
	    0000h ???
	    0001h ???
	    0002h ???
	    0003h "ScheduleAESEvent"
		ES:SI -> AES ECB to be scheduled (see #02997)
		Return: ES,SI preserved
	    0004h "CancelAESEvent"
		ES:SI -> ECB to be cancelled (see #02997)
		Return: ES,SI preserved
	    0005h "GetIntervalMarker"
		Return: DX:AX = current interval marker in milliseconds
			all other registers preserved
	    0006h "RegisterStack"
		AX = logical board number
		ES:SI -> bound stack info structure (see #03007)
		Return: BX = assigned Stack ID if AX=0000h
	    0007h "DeRegisterStack"
		AX = protocol stack's assigned Stack ID
	    0008h "RegisterDefaultStack"
		AX = logical board number
		ES:SI -> stack info structure (see #03008)
	    0009h "DeRegisterDefaultStack"
		AX = logical board number
	    000Ah "RegisterPrescanStack"
		AX = logical board number
		ES:SI -> stack info structure (see #03008)
	    000Bh "DeRegisterPrescanStack"
		AX = logical board number
	    000Ch "SendPacket"
		ES:SI -> send ECB
		Return: interrupts disabled
	    000Dh ???
	    000Eh ???
	    000Fh ???
	    0010h "GetStackIDFromName"
		ES:SI -> counted NUL-terminated protocol name (max 15 chars)
		Return: BX = Stack ID if AX=0000h
	    0011h "GetPIDFromStackIDBoard"
		AX = Stack ID for protocol
		CX = logical board number
		ES:SI -> 6-byte buffer for protocol ID
	    0012h "GetMLIDControlEntry"
		AX = logical board number
		Return: ES:SI -> MLID control handler (see #02995) if AX=0000h
	    0013h "GetProtocolControlEntry"
		AX = Stack ID or
			FFFEh Prescan stack
			    CX = logical board number
			FFFFh default protocol
			    CX = logical board number
		Return: ES:SI -> protocol stack control entry point if AX=0000h
				  (see #02996)
	    0014h "GetLSLStatistics"
		Return: AX = 0000h (successful)
			ZF set
			ES:SI -> LSL statistics table (see #02999)
	    0015h "BindStack"
		AX = protocol stack's assigned Stack ID
		CX = logical board number
	    0016h "UnbindStack"
		AX = protocol stack's assigned Stack ID
		CX = logical board number
	    0017h "AddProtocolID"
		AX = frame type ID code
		ES:SI -> 6-byte protocol ID
		CX:DI -> counted NUL-terminated short protocol name (max 15 ch)
	    0018h "RelinquishControl"
		Return: after LSL performs any necessary background processing
	    0019h "GetLSLConfiguration"
		Return: AX = 0000h (successful)
			ZF set
			ES:SI -> LSL configuration table (see #02998)
	    001Ah "GetTickMarker"
		Return: AX = number of 55ms ticks since LSL loaded
			BX destroyed
Return: AX = completion code (see #02989)
	ZF set if successful
	SS:SP, DS, BP preserved; most other registers may be destroyed