INT 14 - COURIERS.COM - READ CHARACTER                                          
	AH = 84h
Return: ZF set if no characters available
	ZF clear
	   AL = character
	   AH = modem status bits
		bit 7: set on input buffer overflow
SeeAlso: AH=02h,AH=86h,AH=89h
                                                                                

INT 14 - COMM-DRV v14.0 - SEND PACKET                                           
	AH = 84h
	CX = packet length in bytes
	DX = port number
	ES:DI -> packet to be sent
Return: AH = line status (see #00304)
	    bit 7 set on error
	AL destroyed
SeeAlso: AH=83h"COMM-DRV",AH=85h"COMM-DRV",AH=86h"COMM-DRV"