[NVRAMMAP-000]
BIOS NVRAM Usage
Media # 1 CMOS Type ChkSm Bits Byte Offset
reserved fixed no 88 0h 0
cmosDaylightSavings fixed no 1 Bh 0
cmosRegB fixed no 7 Bh 1
cmosRegC fixed no 8 Ch 0
reserved fixed no 7 Dh 0
cmosValidRamBit fixed no 1 Dh 7
reserved fixed no 2 Eh 0
cmosTimeFailedBit fixed no 1 Eh 2
cmosDiskFailedBit fixed no 1 Eh 3
reserved fixed no 1 Eh 4
cmosBadConfigBit fixed no 1 Eh 5
cmosBadChecksumBit fixed no 1 Eh 6
cmosBadPowerbit fixed no 1 Eh 7
cmosShutdown fixed no 8 Fh 0
cmosFdd1Type fixed yes 4 10h 0
cmosFdd0Type fixed yes 4 10h 4
cmosFdisk2ExtType dynamic yes 8 11h 0
cmosFdisk1Type fixed yes 4 12h 0
cmosFdisk0Type fixed yes 4 12h 4
cmosFdisk3ExtType dynamic yes 8 13h 0
cmosEquipment fixed yes 8 14h 0
cmosBaseRam fixed yes 16 15h 0
cmosExtRam fixed yes 16 17h 0
cmosFdisk0ExtType fixed yes 8 19h 0
cmosFdisk1ExtType fixed yes 8 1Ah 0
cmosCylinders2 dynamic yes 12 1Bh 0
cmosComAAddress dynamic yes 4 1Ch 4
cmosCylinders0 fixed yes 12 1Dh 0
cmosHeads0 fixed yes 4 1Eh 4
cmosWP0 fixed yes 12 1Fh 0
cmosLZHI0 fixed yes 4 20h 4
cmosLandingZone0 fixed yes 8 21h 0
cmosSectors0 fixed yes 7 22h 0
cmosReadPrefetch dynamic yes 1 22h 7
cmosCylinders1 fixed yes 12 23h 0
cmosHeads1 fixed yes 4 24h 4
cmosWP1 fixed yes 12 25h 0
cmosLZHI1 fixed yes 4 26h 4
cmosLandingZone1 fixed yes 8 27h 0
cmosSectors1 fixed yes 7 28h 0
cmosHddDosCompat fixed yes 1 28h 7
cmosWP2 dynamic yes 12 29h 0
cmosCylinders3 dynamic yes 12 2Ah 4
cmosWP3 dynamic yes 12 2Ch 0
cmosCom34Base dynamic yes 2 2Dh 4
cmosSystemBIOS fixed yes 1 2Dh 6
cmosVideoBIOS fixed yes 1 2Dh 7
cmosChecksumHi fixed no 8 2Eh 0
cmosChecksumLo fixed no 8 2Fh 0
cmosExtended fixed no 16 30h 0
cmosCentury fixed no 6 32h 0
cmosCacheFlushSize fixed no 2 32h 6
cmosInPostBit fixed no 1 33h 0
cmosConfigFailedBit fixed no 1 33h 1
cmosResume fixed no 1 33h 2
cmosExtCachePresent fixed no 1 33h 3
cmosCR0NW fixed no 1 33h 4
cmosCR0CD fixed no 1 33h 5
cmosCoprocessor387 fixed no 1 33h 6
cmosExpansionInstalled fixed no 1 33h 7
cmosCpuType fixed no 8 34h 0
reserved fixed no 88 35h 0
cmosHdd0MultiMax dynamic yes 8 40h 0
cmosHdd1MultiMax dynamic yes 8 41h 0
cmosHdd2MultiMax dynamic yes 8 42h 0
cmosHdd3MultiMax dynamic yes 8 43h 0
cmosSectors2 dynamic yes 7 44h 0
cmosSectors3 dynamic yes 7 44h 7
cmosLptAddress dynamic yes 4 45h 6
cmosHeads2 dynamic yes 4 46h 2
cmosLZHI2 dynamic yes 4 46h 6
cmosHeads3 dynamic yes 4 47h 2
cmosLptMode dynamic yes 2 47h 6
cmosUserPW0 fixed yes 8 48h 0
cmosUserPW1 fixed yes 8 49h 0
cmosUserPW2 fixed yes 8 4Ah 0
cmosUserPW3 fixed yes 8 4Bh 0
cmosUserPW4 fixed yes 8 4Ch 0
cmosUserPW5 fixed yes 8 4Dh 0
cmosUserPW6 fixed yes 8 4Eh 0
cmosUserCSum fixed yes 8 4Fh 0
cmosSuperPassword fixed yes 8 50h 0
cmosSuperPW1 fixed yes 8 51h 0
cmosSuperPW2 fixed yes 8 52h 0
cmosSuperPW3 fixed yes 8 53h 0
cmosSuperPW4 fixed yes 8 54h 0
cmosSuperPW5 fixed yes 8 55h 0
cmosSuperPW6 fixed yes 8 56h 0
cmosSuperCSum fixed yes 8 57h 0
cmosLZHI3 dynamic yes 4 58h 0
cmosLanguage dynamic yes 4 58h 4
cmosNC0Size dynamic yes 3 59h 0
cmosNC1Size dynamic yes 3 59h 3
cmosGreenTimer1 dynamic yes 3 59h 6
cmosGreenHddStdbyTimer dynamic yes 3 5Ah 1
cmosXferMode0 dynamic yes 3 5Ah 4
cmosXferMode1 dynamic yes 3 5Ah 7
cmosXferMode2 dynamic yes 3 5Bh 2
cmosXferMode3 dynamic yes 3 5Bh 5
cmosHdd0Logical dynamic yes 3 5Ch 0
cmosHdd1Logical dynamic yes 3 5Ch 3
cmosHdd2Logical dynamic yes 3 5Ch 6
cmosHdd3Logical dynamic yes 3 5Dh 1
cmosHddBlockSize0 dynamic yes 3 5Dh 4
cmosHddBlockSize1 dynamic yes 3 5Dh 7
cmosHddBlockSize2 dynamic yes 3 5Eh 2
cmosHddBlockSize3 dynamic yes 3 5Eh 5
cmosNumlock dynamic yes 2 5Fh 0
cmosPS2MouseEnable dynamic yes 1 5Fh 2
cmosCsShdwC800 dynamic yes 1 5Fh 3
cmosCsShdwCC00 dynamic yes 1 5Fh 4
cmosCsShdwD000 dynamic yes 1 5Fh 5
cmosCsShdwD400 dynamic yes 1 5Fh 6
cmosCsShdwD800 dynamic yes 1 5Fh 7
cmosCsShdwDC00 dynamic yes 1 60h 0
cmosMemCacheEnable dynamic yes 1 60h 1
cmosCacheVideo dynamic yes 1 60h 2
cmosCacheWB dynamic yes 1 60h 3
cmosFdcEnable dynamic yes 1 60h 4
cmosIdeEnable dynamic yes 1 60h 5
cmosECP dynamic yes 1 60h 6
cmosDisplaySetupPrompt dynamic yes 1 60h 7
cmosDisplayF1Prompt dynamic yes 1 61h 0
cmosQuickFloppyInit dynamic yes 1 61h 1
cmosSummaryScreen dynamic yes 1 61h 2
cmosHdd32BitIO0 dynamic yes 1 61h 3
cmosHdd32BitIO1 dynamic yes 1 61h 4
cmosHdd32BitIO2 dynamic yes 1 61h 5
cmosHdd32BitIO3 dynamic yes 1 61h 6
cmosHdd0LBAMode dynamic yes 1 61h 7
cmosHdd1LBAMode dynamic yes 1 62h 0
cmosHdd2LBAMode dynamic yes 1 62h 1
cmosHdd3LBAMode dynamic yes 1 62h 2
cmosKeyclick dynamic yes 1 62h 3
cmosPasswordOnBoot dynamic yes 1 62h 4
unused fixed yes 115 62h 5
cmosHdd0Auto fixed yes 1 71h 0
cmosHdd1Auto fixed yes 1 71h 1
cmosHdd2Auto fixed yes 1 71h 2
cmosHdd3Auto fixed yes 1 71h 3
cmosNC0Start dynamic yes 11 71h 4
cmosNC0StLo dynamic yes 8 71h 4
cmosNC0StHi dynamic yes 3 72h 4
cmosNC1Start dynamic yes 11 72h 7
cmosNC1StLo dynamic yes 8 72h 7
cmosNC1StHi dynamic yes 3 73h 7
cmosLandingZone2 dynamic yes 8 74h 2
cmosLandingZone3 dynamic yes 8 75h 2
cmosComBAddress dynamic yes 4 76h 2
cmosBootSequence dynamic yes 2 76h 6
cmosExtMemCnt dynamic no 16 77h 0
cmosPort78 fixed no 5 79h 0
cmosACFGPNPCfgData dynamic no 16 79h 5
cmosCpuSpeed dynamic no 4 7Bh 5
cmosCsCpuConfig dynamic no 4 7Ch 1
cmosMonitorType dynamic no 3 7Ch 5
cmosCacheCpuConfig dynamic no 4 7Dh 0
cmosVgaRefresh dynamic no 1 7Dh 4
cmosOpti611AEnable dynamic no 1 7Dh 5
cmosA20Status dynamic no 1 7Dh 6
cmosCRC dynamic no 16 7Dh 7
unused fixed no 1 7Fh 7
Extended CMOS Checksum Region Start = 40h
Extended CMOS Checksum Region End = 76h
CRC signature = 2004h
CRC mask = FFFFh
Media # 2 None Type ChkSm Bits Byte Offset
Media # 3 None Type ChkSm Bits Byte Offset
Media # 4 None Type ChkSm Bits Byte Offset