[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