Bitfields for Intel 82378/82379 ISA Clock Divisor Register:
Bit(s)	Description	)
 7	reserved (0)
 6	enable positive decode of upper 64K BIOS at 000F0000h-000FFFFFh,
	  FFEF0000h-FFEFFFFFh, and FFFF0000h-FFFFFFFFh
 5	coprocessor error enable
	=1 FERR# is driven onto IRQ13
 4	IRQ12/Mouse Function Enable
	=0 standard IRQ12
	=1 mouse
 3	RSTDRV enable
	=1 assert RSTDRV until this bit cleared (for use in changing ISA bus
	  speed)
 2-0	PCICLK-to-ISA SYSCLK divisor
	000	4
	001	3
	other	reserved
SeeAlso: #01064,#01069