Category: serial I/O

INT 14 - COMM-DRV v14.0 - TURN ON RTS

	AH = 89h
	DX = port number
Return: AH bit 7 set on error
	AH bit 7 clear if successful
SeeAlso: AX=8000h"COMM-DRV",AH=87h"COMM-DRV",AH=8Ah"COMM-DRV"