Bitfields for OPTi 82C750 Vendetta (device 1) miscellaneous control 1:
Bit(s)	Description	)
 7-5	reserved
 4	game port/MPU-401 enable
 3	PREQ4#/PGNT4# mux (0 = SDA2/GP3, 1 = PREQ4#/PGNT4#)
 2	DACK5# 1-to-0 transition enable
 1-0	reserved
SeeAlso: #00939,#00947,#00948