PORTIBM PC Portable (uses same BIOS as XT) 0022-002B - INTEL 82355, PART OF CHIPSET FOR 386sx
Note:	initialisation in POSTsee Power-On Self-Test will disable these addresses, only a hard
	  reset will enable them again.

0022w RW  82335 MCR memory configuration register (if LOCK=0) (see #P0272)
0024w RW  82335 RC1 roll compare register (if LOCK=0) (see #P0273)
0026w RW  82335 RC2 roll compare register (if LOCK=0) (see #P0273)
0028w RW  82335 CC0 address range compare register (if LOCK=0) (see #P0274)
002Aw RW  82335 CC1 address range compare register (if LOCK=0) (see #P0274)


Bitfields for 82335 MCR memory configuration register:
Bit(s)	Description	(Table P0272)
 15-12	reserved
 11	"VRO"	video read only (0=r/w, 1=r/o)
 10	"EN#"
	0=enable video RAM(Random Access Memory)	See also DRAM, SRAM. accesses (A0000h-8FFFFh)
	1=disable accesses
 9	"ENADP#"
	0=enable adapter ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. accesses (C0000h-8FFFFh)
	1=disable adapter ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. accesses, shadow enabled
 8	"ROMSIZE" 0=256KB ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs., 1=512KB ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs.
 7-6	"INTERL" memory interleaving
	00 = 1 memory bank installed (no interleave)
	01 = 2 memory banks installed
	10 = 3 memory banks installed
	11 = 4 memory banks installed
 5	reserved
 4	"DSIZE"	 0=1MBx1DRAMs, 1=256KBx1 or 256KBx4 DRAMs
 3	"S640"	 base memory size is 0=512KB, 1=640KB
 2-1	reserved
 0	"ROMEN#" ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. enable
	0 enable BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. accesses (E0000h-FFFFFh)
	1 disable BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware.  The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. accesses, enable shadow
Note:	One of the remaining reserved bits is the LOCK bit, which will be set
	  during power on, disabling access to the 82335s registers.


Bitfields for 82335 roll compare register:
Bit(s)	Description	(Table P0273)
 15-9	selects address range to be remapped (C23-C17)
 8	reserved
 7-1	selects address bits to be included in re-mapping comparision (M23-M17)
 0	"EN" enables roll address mapping


Bitfields for 82335 address range compare register:
Bit(s)	Description	(Table P0274)
 15-11	specifies top of address range (C23-C19)
 10-8	reserved
 7-3	selects address bits to be included in address range comparision
	  (M23-M19)
 2-1	reserved
 0	"EN" enable address range comparision