INT 14 - COURIERS.COM - START INPUT                                             
	AH = 83h
	ES:BX -> circular input buffer
	CX = length of buffer
		(should be at least 128 bytes if input flow control enabled)
Return: nothing
SeeAlso: AH=18h,AH=87h,AH=8Dh,AH=A5h"BAPI"
                                                                                

INT 14 - COMM-DRV v14.0 - FLUSH COMMUNICATION BUFFERS                           
	AH = 83h
	DX = port number
	AL = subfunction
	    00h flush input buffer
	    01h flush output buffer
	    02h flush both buffers
Return: AH bit 7 set on error
	AH bit 7 clear if successful
SeeAlso: AH=81h"COMM-DRV",AH=84h"COMM-DRV"