Bitfields for Intel 82378/82379 MEMCS# Attribute Register 1/2/3:
Bit(s)	Description	)
 7	write-enable xC000h-xFFFFh expansion ROM
 6	read-enable xC000h-xFFFFh expansion ROM
 5	write-enable x8000h-xBFFFh expansion ROM
 4	read-enable x8000h-xBFFFh expansion ROM
 3	write-enable x4000h-x7FFFh expansion ROM
 2	read-enable x4000h-x7FFFh expansion ROM
 1	write-enable x0000h-x3FFFh expansion ROM
 0	read-enable x0000h-x3FFFh expansion ROM
Note:	x = C/D/E depending on the attribute register
SeeAlso: #01064