INT 14 - ARTICOM - MODIFY FLOW CONTROL AX = 800Ah BL = flow control type (00h none, 01h XON/XOFF, 02h RTS/CTS) DX = port index (COM1=0, COM2=1, ...) Return: AX = error code, if error (see #00360) Note: for attached ports only! SeeAlso: AX=8000h,AX=8003h,AX=8009h