)
Values packet driver receiver is called with when a packet is received:
	AX = subfunction
	    00h get packet buffer
		CX = buffer length
		DX = lookahead length (v1.10+)
		DS:SI -> lookahead buffer if DX nonzero (v1.10+)
		DI = error flags (class dependent) (v1.10+)
		Return: ES:DI -> packet buffer
				0000h:0000h means throw away packet
			CX = size of buffer (v1.10+), may be smaller than
			      incoming data
	    01h copy completed
		DS:SI -> buffer
		CX = bytes actually copied (v1.10+)
	BX = handle