INT 14 - COMM-DRV v14.0 - TURN OFF DTR                                          
	AH = 88h
	DX = port number
Return: AH bit 7 set on error
	AH bit 7 clear if successful
Program: COMM-DRV is a universal serial communications driver by Willies'
	  Computer Software Company, which supports standard INT 14 and
	  FOSSIL(Fido/Opus/Seadog Standard Interface Layer)  A standardized API for performing serial I/O, originally used by the Fido and Opus bulletin- board software and Seadog bulletin-board mailer, but now in wider use. calls as well as its own interfaces
SeeAlso: AX=8000h"COMM-DRV",AH=87h"COMM-DRV",AH=8Ah"COMM-DRV"