INT 14 - MBBIOS - GET/SET OPTIONS
AH = 09h
AL = option byte
00000001b - Transmit Buffering Enabled
00000101b - Hardware Handshaking Enabled
00100000b - High Speed Option Enabled
DX = port number???
Return: AL = old option byte
SeeAlso: AH=10h"FOSSIL"

See also: 1404

1409 - MBBIOS - GET/SET OPTIONS