MEMORY MAP Release 48 Last Change 10/29/95 This compilation is Copyright (c) 1989,1990,1991,1992,1993,1994,1995 Ralf Brown --------H-M00000000-------------------------- MEM 0000h:0000h R - INTERRUPT VECTOR TABLE Size: 1024 BYTEs Note: see also the main interrupt list --------b-M0000031D-------------------------- MEM 0000h:031Dh - 1989 AMI 386sx BIOS - USER-DEFINABLE TYPE 47 HARD DISK PARMS Size: 16 BYTEs Note: these fields are used if the AMI BIOS setup is set to use the top of the interrupt table for the extended BIOS data area SeeAlso: MEM 0000h:032Dh,INT 41 --------b-M0000032D-------------------------- MEM 0000h:032Dh - 1989 AMI 386sx BIOS - USER-DEFINABLE TYPE 48 HARD DISK PARMS Size: 16 BYTEs Note: these fields are used if the AMI BIOS setup is set to use the top of the interrupt table for the extended BIOS data area SeeAlso: MEM 0000h:031Dh,INT 46 --------B-M00000400-------------------------- MEM 0000h:0400h - BIOS DATA AREA Size: 256 BYTEs Note: see also the MEM 0040h:xxxxh entries ----------M00000500-------------------------- MEM 0000h:0500h - DATA AREA Size: 256 BYTEs ----------M00000600-------------------------- MEM 0000h:0600h - MS-DOS 1.x LOAD ADDRESS ----------M00000700-------------------------- MEM 0000h:0700h - MS-DOS 2+ LOAD ADDRESS ----------M00400000-------------------------- MEM 0040h:0000h - BASE I/O ADDRESS OF FIRST SERIAL I/O PORT Size: WORD Notes: the BIOS sets this word to zero if is unable to find any serial ports at the addresses it is programmed to check at boot DOS and BIOS serial device numbers may be redefined by re-assigning these values of the base I/O addresses stored here SeeAlso: MEM 0040h:0002h,MEM 0040h:0004h,MEM 0040h:0006h,MEM 0040h:0008h SeeAlso: MEM 0040h:007Ch ----------M00400002-------------------------- MEM 0040h:0002h - BASE I/O ADDRESS OF SECOND SERIAL I/O PORT Size: WORD Note: the BIOS sets this word to zero if is unable to find more than one serial port at the addresses it is programmed to check at boot SeeAlso: MEM 0040h:0000h,MEM 0040h:0004h,MEM 0040h:0006h,MEM 0040h:000Ah SeeAlso: MEM 0040h:007Dh ----------M00400004-------------------------- MEM 0040h:0004h - BASE I/O ADDRESS OF THIRD SERIAL I/O PORT Size: WORD Note: the BIOS sets this word to zero if is unable to find more than two serial ports at the addresses it is programmed to check at boot SeeAlso: MEM 0040h:0000h,MEM 0040h:0002h,MEM 0040h:0006h,MEM 0040h:000Ch SeeAlso: MEM 0040h:007Eh ----------M00400006-------------------------- MEM 0040h:0006h - BASE I/O ADDRESS OF FOURTH SERIAL I/O PORT Size: WORD Note: the BIOS sets this word to zero if is unable to find more than three serial ports at the addresses it is programmed to check at boot SeeAlso: MEM 0040h:0000h,MEM 0040h:0002h,MEM 0040h:0004h,MEM 0040h:0008h SeeAlso: MEM 0040h:007Fh ----------M00400008-------------------------- MEM 0040h:0008h - BASE I/O ADDRESS OF FIRST PARALLEL I/O PORT Size: WORD Notes: the BIOS POST routine fills in the parallel port address fields in turn as it finds parallel ports. All fields beyond the last one for which a valid parallel port was found are set to zero. the BIOS INT 17 handler uses these fields to address the parallel ports SeeAlso: MEM 0040h:0000h,MEM 0040h:000Ah,MEM 0040h:000Ch ----------M0040000A-------------------------- MEM 0040h:000Ah - BASE I/O ADDRESS OF SECOND PARALLEL I/O PORT Size: WORD Note: zero if fewer than two parallel ports installed SeeAlso: MEM 0040h:0002h,MEM 0040h:0008h,MEM 0040h:000Ch ----------M0040000C-------------------------- MEM 0040h:000Ch - BASE I/O ADDRESS OF THIRD PARALLEL I/O PORT Size: WORD Note: zero if fewer than three parallel ports installed SeeAlso: MEM 0040h:0004h,MEM 0040h:0008h,MEM 0040h:000Ah,MEM 0040h:000Eh ----------M0040000E-------------------------- MEM 0040h:000Eh - BASE I/O ADDRESS OF FOURTH PARALLEL I/O PORT (pre-PS/2) Size: WORD Note: zero if fewer than four parallel ports installed SeeAlso: MEM 0040h:0008h,MEM 0040h:000Ah,MEM 0040h:000Eh"BIOS DATA" ----------M0040000E-------------------------- MEM 0040h:000Eh - SEGMENT OF EXTENDED BIOS DATA SEGMENT (PS/2, newer BIOSes) Size: WORD SeeAlso: MEM 0040h:000Eh"PARALLEL" Format of Extended BIOS Data Area: Offset Size Description (Table M001) 00h BYTE length of EBDA in kilobytes 01h 15 BYTEs reserved 17h BYTE number of entries in POST error log (0-5) 18h 5 WORDs POST error log (each word is a POST error number) 22h DWORD Pointing Device Driver entry point 26h BYTE Pointing Device Flags 1 (see #M002) 27h BYTE Pointing Device Flags 2 (see #M003) 28h 8 BYTEs Pointing Device Auxiliary Device Data 30h DWORD Vector for INT 07h stored here during 80387 interrupt 34h DWORD Vector for INT 01h stored here during INT 07h emulation 38h BYTE Scratchpad for 80287/80387 interrupt code 39h WORD Timer3: Watchdog timer initial count 3Bh BYTE ??? seen non-zero on Model 30 3Ch BYTE ??? 3Dh 16 BYTEs Fixed Disk parameter table for drive 0 (for older machines which don't directly support the installed drive) 4Dh 16 BYTEs Fixed Disk parameter table for drive 1 (for older machines which don't directly support the installed drive) 5Dh-67h ??? 68h BYTE cache control bits 7-2 unused (0) bit 1: CPU cache failed test bit 0: CPU cache disabled 69h-6Bh ??? 6Ch BYTE Fixed disk: (=FFh on ESDI systems) bits 7-4: Channel number 00-0Fh bits 3-0: DMA arbitration level 00-0Eh 6Dh BYTE ??? 6Eh WORD current typematic setting (see INT 16/AH=03h) 70h BYTE number of attached hard drives 71h BYTE hard disk 16-bit DMA channel 72h BYTE interrupt status for hard disk controller (1Fh on timeout) 73h BYTE hard disk operation flags bit 7: controller issued operation-complete INT 76h bit 6: controller has been reset bits 5-0: unused (0) 74h DWORD old INT 76h vector 78h BYTE hard disk DMA type typically 44h for reads and 4Ch for writes 79h BYTE status of last hard disk operation 7Ah BYTE hard disk timeout counter 7Bh-7Dh 7Eh 8 WORDs storage for hard disk controller status 8Eh-E6h E7h BYTE floppy drive type bit 7: drive(s) present bits 6-2: unused (0) bit 1: drive 1 is 5.25" instead of 3.5" bit 0: drive 0 is 5.25" E8h 4 BYTEs ??? ECh BYTE hard disk parameters flag bit 7: parameters loaded into EBDA bits 6-0: unused (0) EDh BYTE ??? EEh BYTE CPU family ID (03h = 386, 04h = 486, etc.) (see INT 15/AH=C9h) EFh BYTE CPU stepping (see INT 15/AH=C9h) F0h 39 BYTEs ??? 117h WORD keyboard ID (see INT 16/AH=0Ah) (most commonly 41ABh) 119h BYTE ??? 11Ah BYTE non-BIOS INT 18h flag bits 7-1: unused (0) bit 0: set by BIOS before calling user INT 18h at offset 11Dh 11Bh 2 BYTE ??? 11Dh DWORD user INT 18h vector if BIOS has re-hooked INT 18h 121h and up: ??? seen non-zero on Model 60 3F0h BYTE Fixed disk buffer (???) Bitfields for Pointing Device Flags 1: Bit(s) Description (Table M002) 7 command in progress 6 resend byte (FAh) received 5 acknowledge byte (FEh) received 4 error byte (FCh) received 3 unexpected value received 2-0 index count for auxiliary device data at 28h SeeAlso: #M001,#M003 Bitfields for Pointing Device Flags 2: Bit(s) Description (Table M003) 7 device driver far call flag 6-3 reserved 2-0 package size (number of bytes received) - 1 SeeAlso: #M001,#M002 ----------M00400010-------------------------- MEM 0040h:0010h - INSTALLED HARDWARE Size: WORD Bitfields for BIOS-detected installed hardware: Bit(s) Description (Table M004) 15-14 number of parallel devices 00 or 11 sometimes used to indicate four LPT ports 13 (Convertible, PS/2-55LS) internal modem 12 game port installed 11-9 number of serial devices 000 or 111 sometimes used to indicate eight COM ports 8 reserved 7-6 number of floppy disk drives (minus 1) 5-4 initial video mode 00 EGA,VGA,PGA, or other with on-board video BIOS 01 40x25 CGA color 10 80x25 CGA color 11 80x25 mono text 3-2 (PC only) RAM on motherboard 00 = 16K, 01 = 32K, 10 = 48K, 11 = 64K 2 (pre-PS/2 except PC) reserved (PS/2, newer BIOSes) pointing device installed 1 math coprocessor installed 0 floppy disk drives are installed booted from floppy ----------M00400012-------------------------- MEM 0040h:0012h - Convertible - POST STATUS Size: BYTE ----------M00400012-------------------------- MEM 0040h:0012h U - AT - MANUFACTURING TEST INITIALIZATION FLAGS Size: BYTE Bitfields for AT manufacturing test initialization flags: Bit(s) Description (Table M005) 0 start in manufacturing test mode rather than normal operation 1-7 unused ----------M00400012-------------------------- MEM 0040h:0012h - MCA - MANUFACTURING TEST Size: BYTE Bitfields for MCA manufacturing test flags : Bit(s) Description (Table M006) 7 POST flag, ??? 6-5 unused 4 POST flag, slot 4 has adapter identifier EDAFh 3 POST flag, 80x25 color video 2 POST flag, ??? 1 unused 0 manufacturing test mode rather than normal operation ----------M00400012-------------------------- MEM 0040h:0012h - PS/2 Model 25 - POST SYSTEM FLAG Size: BYTE Bitfields for PS/2 Model 25 POST sytem flag : Bit(s) Description (Table M007) 0 optional memory failed; memory remapped 1 real-time clock installed ----------M00400013-------------------------- MEM 0040h:0013h - BASE MEMORY SIZE IN KBYTES Size: WORD ----------M00400015-------------------------- MEM 0040h:0015h - PC, XT - ADAPTER MEMORY SIZE IN KBYTES Size: WORD ----------M00400015-------------------------- MEM 0040h:0015h U - AT - MANUFACTURING TEST SCRATCH PAD Size: BYTE ----------M00400015-------------------------- MEM 0040h:0015h - Compaq Deskpro 386 - PREVIOUS SCAN CODE Size: BYTE ----------M00400016-------------------------- MEM 0040h:0016h U - AT - MANUFACTURING TEST SCRATCH PAD Size: BYTE ----------M00400016-------------------------- MEM 0040h:0016h U - PS/2 Model 30 - BIOS CONTROL FLAGS Size: BYTE ----------M00400016-------------------------- MEM 0040h:0016h - Compaq Deskpro 386 - KEYCLICK VOLUME Size: BYTE Range: 00h-7Fh --------K-M00400017-------------------------- MEM 0040h:0017h - KEYBOARD - STATUS FLAGS 1 Size: BYTE SeeAlso: MEM 0040h:0018h,INT 16/AH=01h Bitfields for keyboard status flags 1: Bit(s) Description (Table M008) 7 INSert active 6 Caps Lock active 5 Num Lock active 4 Scroll Lock active 3 either Alt pressed 2 either Ctrl pressed 1 Left Shift pressed 0 Right Shift pressed SeeAlso: #M009 --------K-M00400018-------------------------- MEM 0040h:0018h - KEYBOARD - STATUS FLAGS 2 Size: BYTE SeeAlso: MEM 0040h:0017h,INT 16/AH=01h Bitfields for keyboard status flags 2 : Bit(s) Description (Table M009) 7 INSert pressed 6 Caps Lock pressed 5 Num Lock pressed 4 Scroll Lock pressed 3 Pause state active 2 Sys Req pressed 1 Left Alt pressed 0 Left Ctrl pressed SeeAlso: #M008 --------K-M00400019-------------------------- MEM 0040h:0019h - KEYBOARD - ALT-nnn KEYPAD WORKSPACE Size: BYTE Desc: holds the current value of an Alt-NNN keypad sequence; when Alt is released and this byte is non-zero, the appropriate character is placed in the keyboard buffer SeeAlso: INT 16/AH=00h --------K-M0040001A-------------------------- MEM 0040h:001Ah - KEYBOARD - POINTER TO NEXT CHARACTER IN KEYBOARD BUFFER Size: WORD SeeAlso: MEM 0040h:001Ch,MEM 0040h:0080h,MEM 0040h:0082h,INT 16/AH=00h --------K-M0040001C-------------------------- MEM 0040h:001Ch - KEYBOARD - POINTER TO FIRST FREE SLOT IN KEYBOARD BUFFER Size: WORD SeeAlso: MEM 0040h:001Ah,MEM 0040h:0080h,MEM 0040h:0082h,INT 16/AH=00h --------K-M0040001E-------------------------- MEM 0040h:001Eh - KEYBOARD - DEFAULT KEYBOARD CIRCULAR BUFFER Size: 16 WORDs SeeAlso: MEM 0040h:001Ah,MEM 0040h:001Ch,MEM 0040h:0080h,MEM 0040h:0082h SeeAlso: INT 16/AH=00h ----------M0040003E-------------------------- MEM 0040h:003Eh - DISKETTE - RECALIBRATE STATUS Size: BYTE SeeAlso: MEM 0040h:003Fh,MEM 0040h:0040h Bitfields for diskette recalibrate status: Bit(s) Description (Table M010) 7 diskette hardware interrupt occurred 6-4 reserved 3 recalibrate diskette 3 (PC,XT only) 2 recalibrate diskette 2 (PC,XT only) 1 recalibrate diskette 1 0 recalibrate diskette 0 ----------M0040003F-------------------------- MEM 0040h:003Fh - DISKETTE - MOTOR STATUS Size: BYTE SeeAlso: MEM 0040h:003Eh,MEM 0040h:0040h Bitfields for diskette motor status: Bit(s) Description (Table M011) 7 current operation is write or format, rather than read or verify 6 reserved (DMA enabled on 82077) 5-4 diskette drive number selected (0-3) 3 diskette 3 motor on (PC,XT only) 2 diskette 2 motor on (PC,XT only) 1 diskette 1 motor on 0 diskette 0 motor on ----------M00400040-------------------------- MEM 0040h:0040h - DISKETTE - MOTOR TURN-OFF TIMEOUT COUNT Size: BYTE Desc: number of clock ticks until diskette motor is turned off Note: the typical implementation of the timeout is to have the INT 08 handler decrement this byte on every clock tick, and force the diskette motor off if the result is equal to zero SeeAlso: MEM 0040h:003Eh,MEM 0040h:003Fh,MEM 0040h:0041h ----------M00400041-------------------------- MEM 0040h:0041h - DISKETTE - LAST OPERATION STATUS Size: BYTE SeeAlso: MEM 0040h:003Eh Bitfields for diskette last operation status: Bit(s) Description (Table M012) 7 drive not ready 6 seek error 5 general controller failure 4-0 error reason 00h no error 01h invalid request/parameter 02h address mark not found 03h write-protect error 04h sector not found 06h diskette change line active 08h DMA overrun 09h DMA across 64k boundary 0Ch media type unknown 10h CRC error on read Note: the following values for this byte differ somewhat from the bitfield definition above: 30h drive does not support media sense 31h no media in drive 32h drive does not support media type AAh diskette drive not ready ----------M00400042-------------------------- MEM 0040h:0042h - DISK - FLOPPY/HARD DRIVE STATUS/COMMAND BYTES Size: 7 BYTEs 42h BYTE XT: command byte to hard disk controller AT: write precompensation cylinder number / 4 43h BYTE XT: bit 5 = drive number, bits 3-0=head number AT: sector count 44h BYTE XT: bits 6,7 = high bits of track, bits 5-0 = start sector-1 AT: starting sector 45h BYTE low byte of track number 46h BYTE XT: sector count AT: high bits of track number 47h BYTE XT: controlbyte from HD parameters (step rate,...) AT: 101DHHHH, D=drive number, HHHH=head number 48h BYTE XT: INT 13h subfunction number AT: comand byte to hard disk controller ----------M00400042-------------------------- MEM 0040h:0042h - DISK CONTROLLER STATUS REGISTER 0 Size: BYTE Bitfields for diskette controller status register 0: Bit(s) Description (Table M013) 7-6 interrupt code 00 normal completion 01 abnormal termination during execution 10 invalid command 11 abnormal termination: ready line on/diskette change 5 requested seek complete 4 drive fault 3 drive not ready 2 head state at time of interrupt 1-0 selected drive (drives 2&3 on PC,XT only) ----------M00400043-------------------------- MEM 0040h:0043h - DISK CONTROLLER STATUS REGISTER 1 Size: BYTE Bitfields for diskette controller status register 0: Bit(s) Description (Table M014) 7 attempted access beyon last cylinder 6 unused 5 CRC error on read 4 DMA overrun 3 unused 2 data error 1 disk write protected 0 missing address mark ----------M00400044-------------------------- MEM 0040h:0044h - DISK CONTROLLER STATUS REGISTER 2 Size: BYTE Bitfields for diskette controller status register 0: Bit(s) Description (Table M015) 7 unused 6 found deleted data address mark 5 CRC error in data field 4 wrong cylinder number read 3 verify equal 2 can't find sector matching verify condition 1 bad cylinder 0 unable to find address mark ----------M00400049-------------------------- MEM 0040h:0049h - VIDEO - CURRENT VIDEO MODE Size: BYTE SeeAlso: MEM 0040h:004Ah,INT 10/AH=00h ----------M0040004A-------------------------- MEM 0040h:004Ah - VIDEO - COLUMNS ON SCREEN Size: WORD SeeAlso: MEM 0040h:0049h,MEM 0040h:004Ch,MEM 0040h:004Eh ----------M0040004C-------------------------- MEM 0040h:004Ch - VIDEO - PAGE (REGEN BUFFER) SIZE IN BYTES Size: WORD SeeAlso: MEM 0040h:004Ah,MEM 0040h:004Eh,MEM 0040h:0050h ----------M0040004E-------------------------- MEM 0040h:004Eh - VIDEO - CURRENT PAGE START ADDRESS IN REGEN BUFFER Size: WORD SeeAlso: MEM 0040h:004Ch,MEM 0040h:0050h,MEM 0040h:0062h ----------M00400050-------------------------- MEM 0040h:0050h - VIDEO - CURSOR POSITIONS Size: 8 WORDs Desc: contains row and column position for the cursors on each of eight video pages SeeAlso: MEM 0040h:004Eh,MEM 0040h:0060h ----------M00400060-------------------------- MEM 0040h:0060h - VIDEO - CURSOR TYPE Size: WORD (big-endian) Desc: contains cursor start scan line and cursor end scan line SeeAlso: MEM 0040h:0050h,MEM 0040h:0062h,INT 10/AH=03h ----------M00400062-------------------------- MEM 0040h:0062h - VIDEO - CURRENT PAGE NUMBER Size: BYTE SeeAlso: MEM 0040h:004Eh,MEM 0040h:0063h ----------M00400063-------------------------- MEM 0040h:0063h - VIDEO - CRT CONTROLLER BASE I/O PORT ADDRESS Size: WORD Note: normally 03B4h for mono and 03D4h for color video boards SeeAlso: MEM 0040h:0065h,MEM 0040h:0066h ----------M00400065-------------------------- MEM 0040h:0065h - VIDEO - CURRENT MODE SELECT REGISTER Size: BYTE Desc: contains last value written to I/O port 03B8h / 03D8h SeeAlso: MEM 0040h:0063h,MEM 0040h:0066h Bitfields for current video mode select register: Bit(s) Description (Table M016) 7-6 unused 5 attribute bit 7 controls blinking instead of background 4 mode 6 graphics in monochrome 3 video signal enabled 2 monochrome 1 graphics 0 80x25 text ----------M00400066-------------------------- MEM 0040h:0066h - VIDEO - CURRENT SETTING OF CGA PALETTE REGISTER Size: BYTE Desc: contains the last value written to I/O port 03D9h SeeAlso: MEM 0040h:0063h,MEM 0040h:0065h,INT 10h/AH=0Bh/BH=01h Bitfields for CGA palette register: Bit(s) Description (Table M017) 7-6 unused 5 palette (0/1) 4 intense background colors in text mode 3 intense border color (40x25) / background color (mode 5) 2 red 1 green 0 blue ----------M00400067-------------------------- MEM 0040h:0067h - PC only - CASSETTE TIME COUNT Size: WORD SeeAlso: INT 15/AH=00h ----------M00400067-------------------------- MEM 0040h:0067h - RESET RESTART ADDRESS Size: DWORD Desc: this address stores the address at which to resume execution after a CPU reset (or jump to F000h:FFF0h) when certain magic values are stored at 0040h:0072h or in CMOS RAM location 0Fh SeeAlso: MEM 0040h:0072h,MEM F000h:FFF0h,CMOS 0Fh,INT 19 ----------M00400069-------------------------- MEM 0040h:0069h - CASSETTE (PC only) - CASSETTE CRC REGISTER Size: WORD SeeAlso: MEM 0040h:006Bh"CASSETTE" ----------M00400069-------------------------- MEM 0040h:0069h - V20-XT-BIOS - KEY REPEAT Size: BYTE Bitfields for V20-XT-BIOS key repeat flags: Bit(s) Description (Table M018) 7 key repeat disabled 6 Ctrl-Alt pressed instead of just Alt ----------M0040006B-------------------------- MEM 0040h:006Bh - CASSETTE (PC only) - LAST VALUE READ FROM CASSETTE Size: BYTE SeeAlso: MEM 0040h:0069h"CASSETTE" ----------M0040006B-------------------------- MEM 0040h:006Bh - POST LAST UNEXPECTED INTERRUPT (XT and later) Size: BYTE Desc: this is a bitmask of IRQs which have occurred while the corresponding interrupt vector points at the default system BIOS handler (bit 0 = IRQ0 to bit 7 = IRQ7) ----------M0040006C-------------------------- MEM 0040h:006Ch - TIMER TICKS SINCE MIDNIGHT Size: DWORD SeeAlso: MEM 0040h:0070h,INT 1A/AH=00h ----------M00400070-------------------------- MEM 0040h:0070h - TIMER OVERFLOW Size: BYTE Desc: non-zero if timer has counted past midnight since last call to INT 1A/AH=00h Note: the original IBM BIOS, and thus most other BIOSes, sets this byte to 01h at midnight; a few (such as the Eagle PC-2) increment it each time midnight is passed. The former behavior results in lost days if multiple midnights pass between "get-time" calls while the machine is powered up. SeeAlso: MEM 0040h:006Ch ----------M00400071-------------------------- MEM 0040h:0071h - Ctrl-Break FLAG Size: BYTE Desc: bit 7 is set when Ctrl-Break has been pressed ----------M00400072-------------------------- MEM 0040h:0072h - POST RESET FLAG Size: WORD Desc: specify the action the BIOS should take at the beginning of the power-on self-test when the machine is reset (Table M019) Values for POST reset flag: 0000h cold boot 0064h Burn-in mode 1234h to bypass memory test (warm boot) 4321h [PS/2 except Mod 25,30] to preserve memory 5678h [Conv] system suspended 9ABCh [Conv] manufacturing test mode ABCDh [Conv] POST loop mode ----------M00400074-------------------------- MEM 0040h:0074h - FIXED DISK LAST OPERATION STATUS (except ESDI drives) Size: BYTE SeeAlso: INT 13/AH=01h (Table M020) Values for fixed disk last operation status: 00h no error 01h invalid function request 02h address mark not found 03h write protect error 04h sector not found 05h reset failed 06h diskette removed 07h drive parameter activity failed 08h DMA overrun 09h DMA data boundary error 0Ah bad sector flag detected 0Bh bad track detected 0Ch requested diskette media type not found (PS/2 or extended BIOS only) unsupported track 0Dh invalid number of sectors for Format 0Eh control data address mark detected 0Fh DMA arbitration level out of range 10h uncorrectable ECC or CRC error 11h ECC corrected data error 20h general controller failed 40h seek failed 80h time out AAh drive not ready BBh undefined error CCh write fault on selected drive E0h status error/error register is zero FFh sense failed ----------M00400074-------------------------- MEM 0040h:0074h - WD1002-27X SuperBIOS - TOTAL DRIVES, FIRST CONTROLLER ONLY Size: BYTE SeeAlso: MEM 0040h:0075h"SuperBIOS",MEM 0040h:0076h"SuperBIOS" ----------M00400075-------------------------- MEM 0040h:0075h - FIXED DISK - NUMBER OF FIXED DISK DRIVES Size: BYTE SeeAlso: MEM 0040h:0076h"FIXED DISK",MEM 0040h:0077h"FIXED DISK" ----------M00400075-------------------------- MEM 0040h:0075h - WD1002-27X SuperBIOS - TOTAL FIXED DRIVES, BOTH CONTROLLERS Size: BYTE SeeAlso: MEM 0040h:0074h"SuperBIOS",MEM 0040h:0076h"SuperBIOS" ----------M00400076-------------------------- MEM 0040h:0076h - FIXED DISK - CONTROL BYTE {IBM document only for XT} Size: BYTE SeeAlso: MEM 0040h:0075h"FIXED DISK",MEM 0040h:0077h"FIXED DISK" ----------M00400076-------------------------- MEM 0040h:0076h - XT: hard disk controller's I/O address (Western Digital) Size: BYTE ----------M00400076-------------------------- MEM 0040h:0076h - WD1002-27X SuperBIOS - USED IN TRACK RECALCULATION Size: BYTE SeeAlso: MEM 0040h:0074h"SuperBIOS",MEM 0040h:0075h"SuperBIOS" SeeAlso: MEM 0040h:0077h"SuperBIOS" ----------M00400077-------------------------- MEM 0040h:0077h - FIXED DISK - I/O port offset {IBM document only for XT} Size: BYTE SeeAlso: MEM 0040h:0075h"FIXED DISK",MEM 0040h:0076h"FIXED DISK" ----------M00400077-------------------------- MEM 0040h:0077h - WD1002-27X SuperBIOS - USED IN TRACK RECALCULATION Size: BYTE SeeAlso: MEM 0040h:0076h"SuperBIOS" ----------M00400078-------------------------- MEM 0040h:0078h - PARALLEL DEVICE 1 TIME-OUT COUNTER Size: BYTE SeeAlso: MEM 0040h:0079h,MEM 0040h:007Ah ----------M00400079-------------------------- MEM 0040h:0079h - PARALLEL DEVICE 2 TIME-OUT COUNTER Size: BYTE SeeAlso: MEM 0040h:0078h,MEM 0040h:007Ah ----------M0040007A-------------------------- MEM 0040h:007Ah - PARALLEL DEVICE 3 TIME-OUT COUNTER Size: BYTE SeeAlso: MEM 0040h:0078h,MEM 0040h:0079h,MEM 0040h:007Bh"PARALLEL" ----------M0040007B-------------------------- MEM 0040h:007Bh - PARALLEL DEVICE 4 TIME-OUT COUNTER (pre-PS, PS Models 25,30) Size: BYTE SeeAlso: MEM 0040h:0078h,MEM 0040h:007Ah,MEM 0040h:007Bh"INT 4Bh" ----------M0040007B-------------------------- MEM 0040h:007Bh - INT 4Bh FLAGS (PS2 and newer) Size: BYTE Bitfields for INT 4Bh flags: Bit(s) Description (Table M021) 7-6 reserved 5 set if Virtual DMA Spec supported [PS] (see INT 4B) 4 reserved 3 set if INT 4Bh intercepted and must be chained 2 reserved 1 set if Generic SCSI CBIOS services available on INT 4Bh 0 reserved ----------M0040007C-------------------------- MEM 0040h:007Ch - SERIAL DEVICE 1 TIMEOUT COUNTER Size: BYTE SeeAlso: MEM 0040h:0000h,MEM 0040h:007Dh,MEM 0040h:007Eh,MEM 0040h:007Fh ----------M0040007D-------------------------- MEM 0040h:007Dh - SERIAL DEVICE 2 TIMEOUT COUNTER Size: BYTE SeeAlso: MEM 0040h:0002h,MEM 0040h:007Ch,MEM 0040h:007Eh,MEM 0040h:007Fh ----------M0040007E-------------------------- MEM 0040h:007Eh - SERIAL DEVICE 3 TIMEOUT COUNTER Size: BYTE SeeAlso: MEM 0040h:0004h,MEM 0040h:007Ch,MEM 0040h:007Dh,MEM 0040h:007Fh ----------M0040007F-------------------------- MEM 0040h:007Fh - SERIAL DEVICE 4 TIMEOUT COUNTER Size: BYTE SeeAlso: MEM 0040h:0006h,MEM 0040h:007Ch,MEM 0040h:007Dh,MEM 0040h:007Eh ----------M00400080-------------------------- MEM 0040h:0080h - KEYBOARD BUFFER START OFFSET FROM SEGMENT 40h (normally 1Eh) Size: WORD SeeAlso: MEM 0040h:001Ah,MEM 0040h:001Eh,MEM 0040h:0082h ----------M00400082-------------------------- MEM 0040h:0082h - KEYBOARD BUFFER END+1 OFFSET FROM SEGMENT 40h (normally 3Eh) Size: WORD Note: XT BIOS dated 11/08/82 ends here SeeAlso: MEM 0040h:001Ch,MEM 0040h:003Eh,MEM 0040h:0080h ----------M00400084-------------------------- MEM 0040h:0084h - VIDEO (EGA/MCGA/VGA) - ROWS ON SCREEN MINUS ONE Size: BYTE ----------M00400085-------------------------- MEM 0040h:0085h - VIDEO (EGA/MCGA/VGA) - CHARACTER HEIGHT IN SCAN-LINES Size: WORD ----------M00400087-------------------------- MEM 0040h:0087h - VIDEO (EGA/VGA) CONTROL: [MCGA: =00h] Size: BYTE Bitfields for EGA/VGA Video control flags: Bit(s) Description (Table M022) 7 do not to clear RAM on mode set (see INT 10h, AH=00h) 6-5 RAM on adapter = (this field + 1) * 64K 4 reserved 3 EGA/VGA video system INactive 2 wait for display enable 1 mono monitor 0 alphanumeric cursor emulation DISabled When enabled, text mode cursor size (INT 10,AH=01h) settings looking like CGA ones are translated to equivalent EGA/VGA ones. ----------M00400088-------------------------- MEM 0040h:0088h - VIDEO (EGA/VGA) SWITCHES: [MCGA: reserved] Size: BYTE SeeAlso: MEM 0040h:0087h,MEM 0040h:0088h Bitfields for EGA/VGA Video switches: Bit(s) Description (Table M023) 7-4 power-on state of feature connector bits 3-0 3-0 configuration switches 4-1 (=0 on, =1 off) (see #M024) Note: when bit 4 of 0040h:0089h is 0, VGA emulates 350-line EGA if this byte is x3h or x9h, otherwise emulates 200-line CGA in 400-line double scan. VGA resets this byte to x9h after the mode set. See also note for 0040h:0089h. (Table M024) Values for EGA/VGA configuration switches: 00h Pri MDA, Sec EGA+old color display 40 x 25 01h Pri MDA, Sec EGA+old color display 80 x 25 02h Pri MDA, Sec EGA+ECD normal mode (CGA emul) 03h Pri MDA, Sec EGA+ECD enhanced mode 04h Pri CGA 40 x 25, Sec EGA mono display 05h Pri CGA 80 x 25, Sec EGA mono display 06h Pri EGA+old color display 40 x 25, Sec MDA 07h Pri EGA+old color display 80 x 25, Sec MDA 08h Pri EGA+ECD normal mode (CGA emul), Sec MDA 09h Pri EGA+ECD enhanced mode, Sec MDA 0Ah Pri EGA mono display, Sec CGA 40 x 25 0Bh Pri EGA mono display, Sec CGA 80 x 25 SeeAlso: #M023 ----------M00400089-------------------------- MEM 0040h:0089h U - VIDEO (MCGA/VGA) - MODE-SET OPTION CONTROL Size: BYTE Bitfields for Video mode-set option control: Bit(s) Description (Table M025) 7,4 requested scan lines 0 0 350-line mode requested 0 1 400-line mode at next mode set 1 0 200-line mode requested 1 1 reserved Note: Apparently VGA BIOS mode set disregards bit 7 and uses byte 40h:88h to determine 200/350 selection when bit 4 is zero. Presumably bit 7 is a convenience for other purposes. Bit 7 is reset to zero after the mode set. 6 display switching enabled 5 reserved 4 if set: use 400-line mode at next mode set if clear: [VGA] emulate EGA at next mode set [MCGA] emulate CGA, digital monitor, 200 lines, 8x8 text Note: this bit is set by the video mode set on VGA, unchanged on MCGA 3 default palette loading DISabled at mode set 2 mono display 1 gray scale summing enabled 0 [VGA] =1 if VGA active, =0 if not [MCGA] reserved, zero Note: the Tseng ET4000 BIOS v3.00 uses bits 6-4 of 88h and bits 6-5 of 89h to specify graphics-mode refresh rates as follows 88h/6 640x480: 1 for 72Hz,0 for 60Hz 88h/5+89h/6 800x600: 00 60Hz 01 56Hz 11 72Hz 88h/4+89h/5 1024x768: 00 interlaced 01 60Hz 10 72Hz??? 11 70Hz ----------M0040008A-------------------------- MEM 0040h:008Ah U - VIDEO (MCGA/VGA) - INDEX INTO DISPLAY COMBINATION CODE TBL Size: BYTE ----------M0040008B-------------------------- MEM 0040h:008Bh - PC, PCjr, PC/XT 11/8/82, Convertible - RESERVED Size: 11 BYTEs ----------M0040008B-------------------------- MEM 0040h:008Bh - DISKETTE MEDIA CONTROL Size: BYTE Bitfields for diskette media control: Bit(s) Description (Table M026) 7-6 last data rate set by controller 00=500kbps, 01=300kbps, 10=250kbps, 11=1Mbps 5-4 last diskette drive step rate selected 00=0Ch, 01=0Dh, 10=0Eh, 11=0Ah 3-2 {data rate at start of operation} 1-0 reserved Note: EHD BIOS sets this byte to 01h and never reads it back ----------M0040008C-------------------------- MEM 0040h:008Ch - FIXED DISK - CONTROLLER STATUS [not XT] Size: BYTE SeeAlso: MEM 0040h:008Dh,MEM 0040h:008Eh ----------M0040008D-------------------------- MEM 0040h:008Dh - FIXED DISK - CONTROLLER ERROR STATUS [not XT] Size: BYTE SeeAlso: MEM 0040h:008Ch,MEM 0040h:008Eh ----------M0040008E-------------------------- MEM 0040h:008Eh - FIXED DISK - INTERRUPT CONTROL [not XT] Size: BYTE Note: cleared to 00h at start of disk operation, set to FFh by IRQ14 handler when hard disk controller completes command SeeAlso: MEM 0040h:008Ch,MEM 0040h:008Dh,MEM 0040h:008Fh ----------M0040008F-------------------------- MEM 0040h:008Fh U - DISKETTE CONTROLLER INFORMATION [not XT] Size: BYTE SeeAlso: MEM 0040h:008Ch,MEM 0040h:008Dh,MEM 0040h:008Eh Bitfields for diskette controller information: Bit(s) Description (Table M027) 7 reserved 6 =1 drive 1 determined 5 =1 drive 1 is multi-rate, valid if drive determined 4 =1 drive 1 supports 80 tracks, always valid 3 reserved 2 =1 drive 0 determined 1 =1 drive 0 is multi-rate, valid if drive determined 0 =1 drive 0 supports 80 tracks, always valid Note: EHD BIOS sets this byte to 01h and never alters it again ----------M00400090-------------------------- MEM 0040h:0090h - DISKETTE DRIVE 0 MEDIA STATE Size: BYTE SeeAlso: MEM 0040h:0091h Bitfields for diskette drive media state: Bit(s) Description (Table M028) 7-6 data rate 00=500kbps, 01=300kbps, 10=250kbps, 11=1Mbps 5 double stepping required (e.g. 360kB in 1.2MB) 4 media type established 3 drive capable of supporting 4MB media 2-0 on exit from BIOS, contains 000 trying 360kB in 360kB 001 trying 360kB in 1.2MB 010 trying 1.2MB in 1.2MB 011 360kB in 360kB established 100 360kB in 1.2MB established 101 1.2MB in 1.2MB established 110 reserved 111 all other formats/drives SeeAlso: #M029,#M030 ----------M00400091-------------------------- MEM 0040h:0091h - DISKETTE DRIVE 1 MEDIA STATE Size: BYTE SeeAlso: MEM 0040h:0090h,#M028 ----------M00400092-------------------------- MEM 0040h:0092h U - DISKETTE DRIVE 0 MEDIA STATE AT START OF OPERATION Size: BYTE Note: officially "Drive 2 media state" SeeAlso: MEM 0040h:0093h"DRIVE 1" Bitfields for diskette drive 0 media state at start of operation: Bit(s) Description (Table M029) 7-3 (see #M028) 2 multiple data rate capability determined 1 multiple data rate capability 0 =1 if drive has 80 tracks, =0 if 40 tracks SeeAlso: #M028,#M030 ----------M00400092-------------------------- MEM 0040h:0092h - Olivetti Quaderno - HARD DISK POWERDOWN COUNTDOWN CLOCK TICKS Size: BYTE Note: hard disk is turned off when counter reaches zero ----------M00400093-------------------------- MEM 0040h:0093h U - DISKETTE DRIVE 1 MEDIA STATE AT START OF OPERATION Size: BYTE Note: officially "Drive 3 media state" SeeAlso: MEM 0040h:0092h"DRIVE 0" Bitfields for diskette drive 1 media state at start of operation: Bit(s) Description (Table M030) 7-3 (see #M028) 2 multiple data rate capability determined 1 multiple data rate capability 0 =1 if drive has 80 tracks, =0 if 40 tracks --HP 100LX/200LX-- display control status 0 =1 if DISPCTL -K 1 =1 if DISPCTL -C ----------M00400094-------------------------- MEM 0040h:0094h - DISKETTE DRIVE 0 CURRENT TRACK NUMBER Size: BYTE SeeAlso: MEM 0040h:0095h ----------M00400095-------------------------- MEM 0040h:0095h - DISKETTE DRIVE 1 CURRENT TRACK NUMBER Size: BYTE SeeAlso: MEM 0040h:0094h ----------M00400096-------------------------- MEM 0040h:0096h - KEYBOARD STATUS BYTE 1 Size: BYTE Bitfields for keyboard status byte 1: Bit(s) Description (Table M031) 7 =1 read-ID in progress 6 =1 last code read was first of two ID codes 5 =1 force Num Lock if read-ID and enhanced keyboard 4 =1 enhanced keyboard installed 3 =1 Right Alt pressed 2 =1 Right Ctrl pressed 1 =1 last code read was E0h 0 =1 last code read was E1h SeeAlso: #M032 ----------M00400097-------------------------- MEM 0040h:0097h - KEYBOARD STATUS BYTE 2 Size: BYTE Bitfields for keyboard status byte 2: Bit(s) Description (Table M032) 7 =1 keyboard transmit error flag 6 =1 LED update in progress 5 =1 RESEND received from keyboard 4 =1 ACK received from keyboard 3 reserved, must be zero 2 Caps Lock LED 1 Num Lock LED 0 Scroll Lock LED SeeAlso: #M031 ----------M00400098-------------------------- MEM 0040h:0098h - TIMER2 (AT, PS exc Mod 30) - PTR TO USER WAIT-COMPLETE FLAG Size: DWORD Note: (see INT 15/AX=8300h) ----------M0040009C-------------------------- MEM 0040h:009Ch - TIMER2 (AT, PS exc Mod 30) - USER WAIT COUNT IN MICROSECONDS Size: DWORD ----------M0040009F-------------------------- MEM 0040h:009Fh - HP 100LX/200LX - VIDEO ZOOM MODE Size: BYTE (Table M033) Values for HP 100LX/200LX video zoom mode: 02h 80x25 mono 03h 80x25 color 80h 64x18 mono 81h 64x18 color 82h 40x25 mono 83h 40x25 color 84h 40x16 mono 85h 40x16 color SeeAlso: INT 10/AH=D0h ----------M004000A0-------------------------- MEM 0040h:00A0h - TIMER2 (AT, PS exc Mod 30) - WAIT ACTIVE FLAG Size: BYTE Bitfields for Timer2 wait active flag: Bit(s) Description (Table M034) 7 wait time elapsed 6-1 reserved 0 INT 15/AH=86h has occurred ----------M004000A1-------------------------- MEM 0040h:00A1h - BIT 5 SET IF LAN SUPPORT PROGRAM INTERRUPT ARBITRATOR PRESENT Size: BYTE Note: DEVICE=DXMA0MOD.SYS ----------M004000A2-------------------------- MEM 0040h:00A2h - RESERVED FOR NETWORK ADAPTERS Size: 6 BYTEs ----------M004000A4-------------------------- MEM 0040h:00A4h - PS/2 Mod 30 - SAVED FIXED DISK INTERRUPT VECTOR Size: DWORD ----------M004000A8-------------------------- MEM 0040h:00A8h - VIDEO (EGA/MCGA/VGA) - POINTER TO VIDEO SAVE POINTER TABLE Size: DWORD Format of Video Save Pointer Table [EGA/VGA/MCGA only]: Offset Size Description (Table M035) 00h DWORD ptr to Video Parameter Table 04h DWORD ptr to Parameter Dynamic Save Area, else 0 [EGA/VGA only] 08h DWORD ptr to Alphanumeric Character Set Override, else 0 0Ch DWORD ptr to Graphics Character Set Override, else 0 10h DWORD [VGA only] ptr to Secondary Save Pointer Table, must be valid 14h DWORD reserved, zero 18h DWORD reserved, zero Note: table initially in ROM, copy to RAM to alter, then update 40h:A8h. Format of Secondary Video Save Pointer Table [VGA only]: Offset Size Description (Table M036) 00h WORD Length of this table in bytes, including this word (1Ah) 02h DWORD ptr to Display Combination Code Table, must be valid 06h DWORD ptr to second Alphanumeric Character Set Override, else 0 0Ah DWORD ptr to User Palette Profile Table, else 0 0Eh DWORD reserved, zero 12h DWORD reserved, zero 16h DWORD reserved, zero Note: table initially in ROM, copy to RAM to alter, then alter Save Ptr Table. Format of Display Combination Code Table [VGA only]: Offset Size Description (Table M037) 00h BYTE Number of entries in the DCC table at offset 04h 01h BYTE Version number 02h BYTE Maximum display type code that can appear in DCC table 03h BYTE reserved 04h 2N BYTEs Each pair of bytes gives a valid display combination Meaning of each byte: 00h no display 01h MDA with mono display 02h CGA with color display 03h reserved 04h EGA with color display 05h EGA with mono display 06h Professional Graphics Controller 07h VGA with mono display 08h VGA with color display 09h reserved 0Ah MCGA with digital color display 0Bh MCGA with analog mono display 0Ch MCGA with analog color display FFh unrecognised video system Format of Video Parameter Table [EGA, VGA only]: Offset Size Description (Table M038) 00h-03h Modes 00h-03h in 200-line CGA emulation mode 04h-0Eh Modes 04h-0Eh 0Fh-10h Modes 0Fh-10h when only 64kB RAM on adapter 11h-12h Modes 0Fh-10h when >64kB RAM on adapter 13h-16h Modes 00h-03h in 350-line mode 17h VGA Modes 00h or 01h in 400-line mode 18h VGA Modes 02h or 03h in 400-line mode 19h VGA Mode 07h in 400-line mode 1Ah-1Ch VGA Modes 11h-13h Note: An array of 23 [EGA] or 29 [VGA] elements, each element being 64 bytes long. Elements appear in the above order. Format of Video Parameter Table element [EGA, VGA only]: Offset Size Description (Table M039) 00h BYTE Columns on screen (see 40h:4Ah) 01h BYTE Rows on screen minus one (see 40h:84h) 02h BYTE Height of character in scan lines (see 40h:85h) 03h WORD Size of video buffer (see 40h:4Ch) 05h 4 BYTEs Values for Sequencer Registers 1-4 09h BYTE Value for Miscellaneous Output Register 0Ah 25 BYTEs Values for CRTC Registers 00h-18h 23h 20 BYTEs Values for Attribute Controller Registers 00h-13h 37h 9 BYTEs Values for Graphics Controller Registers 00h-08h Format of Video Parameter Table [MCGA only] {guesswork from inspection}: Offset Size Description (Table M040) - 16 triplet BYTEs of R,G,B DAC info for 16 colors; - An array of 11 elements, each element being 32 bytes long. Elements appear in the order: Modes 00h,01h in 200-line mode for digital displays Modes 00h,01h in 400-line mode for analog displays Modes 02h,03h in 200-line mode for digital displays Modes 02h,03h in 400-line mode for analog displays Modes 04h,05h in 200-line mode for digital displays Modes 04h,05h in 400-line mode for analog displays Mode 06h in 200-line mode for digital displays Mode 06h in 400-line mode for analog displays Mode 11h Mode 13h in 200-line mode for digital displays Mode 13h in 400-line mode for analog displays Format of Video Parameter Table element [MCGA only]: Offset Size Description (Table M041) 00h BYTE Columns on screen (see 40h:4Ah) 01h BYTE Rows on screen minus one (see 40h:84h) 02h BYTE Height of character in scan lines (see 40h:85h) 03h WORD Size of video buffer (see 40h:4Ch) 05h WORD ??? always zero 07h 21 BYTEs Video data registers 00h-14h to port 3D5h indexed by 3D4h 1Ch BYTE PEL Mask to port 3C6h 1Dh BYTE CGA Mode Control to port 3D8h 1Eh BYTE CGA Border Control to port 3D9h 1Fh BYTE Extended Mode Control to port 3DDh Format of Video Parameter Dynamic Save Area [EGA, VGA only]: Offset Size Description (Table M042) 00h 16 BYTEs Last data written to Attribute Contr. Palette Registers 0-15 10h BYTE Last data written to Attribute Controller Overscan Register 11h-FFh Reserved Note: Need for table was that EGA registers were write-only. Note: If default values (from the Video Parameter Table) are over-ridden at a mode set by the VGA User Palette Profile Table, then the Dynamic Save Area is updated with the default values, not the User Profile ones. Format of Alphanumeric Character Set Override: Offset Size Description (Table M043) 00h BYTE Length in bytes of each character in font table 01h BYTE Character generator RAM bank to load, 0=normal 02h WORD Number of characters in font table, normally 256 04h WORD Code of first character in font table, normally 0 06h DWORD ptr to font table 0Ah BYTE Displayable rows (FFh=use maximum calculated value) 0Bh BYTEs Array of mode values to which this font is to pertain BYTE FFh end of array Format of Second Alphanumeric Character Set Override: Offset Size Description (Table M044) 00h BYTE Length in bytes of each character in font table 01h BYTE Character generator RAM bank to load, normally non-zero 02h BYTE reserved 03h DWORD ptr to font table 07h BYTEs Array of mode values to which this font is to pertain BYTE FFh end of array Note: Authorities differ, some say same as first override above, but IBM says it is as shown above Format of Graphics Character Set Override: Offset Size Description (Table M045) 00h BYTE Number of displayable character rows 01h WORD Length in bytes of each character in font table 03h DWORD ptr to font table 07h BYTEs Array of mode values to which this font is to pertain BYTE FFh end of array Format of User Palette Profile Table [VGA only]: Offset Size Description (Table M046) 00h BYTE Underlining: 01h=enable in all alphanumeric modes 00h=enable in monochrome alphanumeric modes only FFh=disable in all alphanumeric modes 01h BYTE reserved 02h WORD reserved 04h WORD Number (0-17) of Attribute Controller registers in table 06h WORD Index (0-16) of first Attribute Controller register in table 08h DWORD ptr to table of Attribute Controller registers to override Table is an array of BYTEs. 0Ch WORD Number (0-256) of video DAC Color registers in table 0Eh WORD Index (0-255) of first video DAC Color register in table 10h DWORD ptr to table of video DAC Color registers to override Table is ??? triplets ??? of BYTEs??? 14h BYTEs array of mode values to which this profile is to pertain BYTE FFh end of array ----------M004000AC-------------------------- MEM 0040h:00ACh - RESERVED Size: 4 BYTEs ----------M004000B0-------------------------- MEM 0040h:00B0h - Phoenix 386 BIOS 1.10 10a - LOOP COUNT FOR HARD DISK TIMEOUT Size: BYTE Desc: number of times a tight software delay loop should be executed to generate the sub-55ms delays used internally by the BIOS Note: also used for delaying when beeping due to full keyboard buffer ----------M004000B0-------------------------- MEM 0040h:00B0h - PTR TO 3363 OPTICAL DISK DRIVER OR BIOS ENTRY POINT Size: DWORD Notes: When 3363 BIOS present, the ASCIZ signature "OPTIC "occurs 3 bytes beyond this entry point When 3363 BIOS and 3363 File System Driver present, the ASCIZ signature "FILE SYSTEM DRIVER" occurs 3 bytes beyond this entry point ----------M004000B0-------------------------- MEM 0040h:00B0h - 1988 Phoenix 386 BIOS 1.10 03 - PARAMS FOR TYPE 48 HARD DISK Size: 16 BYTEs SeeAlso: INT 41,INT 46 ----------M004000B4-------------------------- MEM 0040h:00B4h - RESERVED Size: WORD ----------M004000B5-------------------------- MEM 0040h:00B5h - Dell 4xxDE Size: BYTE Bitfields for Dell 4xxDE flags: Bit(s) Description (Table M047) 2 ??? (related to disk drives) 5 page tables set to allow Weitek addressing in real mode 6 Weitek math coprocessor present ----------M004000B6-------------------------- MEM 0040h:00B6h - RESERVED FOR POST??? Size: 3 BYTEs ----------M004000B9-------------------------- MEM 0040h:00B9h - ??? Size: 7 BYTEs ----------M004000C0-------------------------- MEM 0040h:00C0h - 1988 Phoenix 386 BIOS 1.10 03 - PARAMS FOR TYPE 49 HARD DISK Size: 16 BYTEs SeeAlso: INT 41,INT 46 ----------M004000C0-------------------------- MEM 0040h:00C0h - RESERVED Size: 14 BYTEs ----------M004000CE-------------------------- MEM 0040h:00CEh - COUNT OF DAYS SINCE LAST BOOT Size: WORD ----------M004000D0-------------------------- MEM 0040h:00D0h - RESERVED Size: 32 BYTEs ----------M004000D0-------------------------- MEM 0040h:00D0h - Digiboard MV/4 - LENGTH OF DATA TABLE Size: BYTE ----------M004000D0-------------------------- MEM 0040h:00D0h EHD floppy - INSTALLATION FLAGS Size: BYTE Bitfields for EHD floppy installation flags: Bit(s) Description (Table M048) 4 installation completed 3-0 drives 0-3 ----------M004000D1-------------------------- MEM 0040h:00D1h - Digiboard MV/4 - PRODUCT ID Size: BYTE ----------M004000D2-------------------------- MEM 0040h:00D2h - Digiboard MV/4 - BASE ADDRESS FOUND Size: WORD ----------M004000D4-------------------------- MEM 0040h:00D4h - Digiboard MV/4 - PORTS Size: BYTE ----------M004000D5-------------------------- MEM 0040h:00D5h - Digiboard MV/4 - IRQ Size: BYTE ----------M004000D5-------------------------- MEM 0040h:00D5h - EHD floppy - NUMBER OF FLOPPY DISK CONTROLLERS IN SYSTEM Size: BYTE ----------M004000D6-------------------------- MEM 0040h:00D6h - EHD floppy - AND-BITS TO ADJUST PORT ADDRESS Size: BYTE Note: this byte contains FFh if controller at 03Fxh and 7Fh if at 037xh; the value is ANDed with DL prior to using IN A?,DX or OUT DX,A? instructions ----------M004000D6-------------------------- MEM 0040h:00D6h - Digiboard MV/4 - NUMBER OF KEYBOARDS FOUND Size: WORD SeeAlso: MEM 0040h:00D8h"Digiboard" ----------M004000D7-------------------------- MEM 0040h:00D7h - EHD floppy - DRIVE 0 DISKETTE MEDIA STATE Size: BYTE Note: the value in this byte is copied into 0040h:0090h (diskette 0 status) SeeAlso: MEM 0040h:00D8h"EHD",MEM 0040h:00D9h"EHD",MEM 0040h:00DAh"EHD" Bitfields for EHD diskette media state: Bit(s) Description (Table M049) 7-6 data rate: 00=500kbps,01=300kbps,10=250k,11=1M/S 5 double stepping required (e.g. 360kB in 1.2MB) 4 media type established 3 reserved 2-0 on exit from BIOS, contains: 000 trying 360kB in 360kB 001 trying 360kB in 1.2MB 010 trying 1.2MB in 1.2MB 011 360kB in 360kB established 100 360kB in 1.2MB established 101 1.2MB in 1.2MB established 110 reserved (2M8?) 111 all other formats/drives ----------M004000D8-------------------------- MEM 0040h:00D8h - Digiboard MV/4 - NUMBER OF MICE FOUND Size: WORD SeeAlso: MEM 0040h:00D6h"Digiboard",MEM 0040h:00DAh"Digiboard" ----------M004000D8-------------------------- MEM 0040h:00D8h - EHD floppy - DRIVE 1 DISKETTE MEDIA STATE Size: BYTE SeeAlso: MEM 0040h:00D7h"EHD",MEM 0040h:00D9h"EHD",MEM 0040h:00DAh"EHD" ----------M004000D9-------------------------- MEM 0040h:00D9h - EHD floppy - DRIVE 2 DISKETTE MEDIA STATE Size: BYTE SeeAlso: MEM 0040h:00D7h"EHD",MEM 0040h:00D8h"EHD",MEM 0040h:00DAh"EHD" ----------M004000DA-------------------------- MEM 0040h:00DAh - Digiboard MV/4 - CURRENT PORT (used by VGA initializatn only) Size: BYTE SeeAlso: MEM 0040h:00D8h"Digiboard" ----------M004000DA-------------------------- MEM 0040h:00DAh - EHD floppy - DRIVE 3 DISKETTE MEDIA STATE Size: BYTE SeeAlso: MEM 0040h:00D7h"EHD",MEM 0040h:00D8h"EHD",MEM 0040h:00D9h"EHD" ----------M004000DB-------------------------- MEM 0040h:00DBh - Digiboard MV/4 - MASTER 8259 MASK (used by VGA init only) Size: BYTE SeeAlso: MEM 0040h:00DCh"Digiboard" ----------M004000DB-------------------------- MEM 0040h:00DBh - EHD floppy - DRIVE 0 NEEDS RECALIBARATION Size: BYTE SeeAlso: MEM 0040h:00DCh"EHD",MEM 0040h:00DDh"EHD",MEM 0040h:00DEh"EHD" ----------M004000DC-------------------------- MEM 0040h:00DCh - Digiboard MV/4 - SLAVE 8259 MASK (used by VGA init only) Size: BYTE SeeAlso: MEM 0040h:00DBh"Digiboard" ----------M004000DC-------------------------- MEM 0040h:00DCh - EHD floppy - DRIVE 1 NEEDS RECALIBARATION Size: BYTE SeeAlso: MEM 0040h:00DBh"EHD",MEM 0040h:00DDh"EHD",MEM 0040h:00DEh"EHD" ----------M004000DD-------------------------- MEM 0040h:00DDh - EHD floppy - DRIVE 2 NEEDS RECALIBARATION Size: BYTE SeeAlso: MEM 0040h:00DBh"EHD",MEM 0040h:00DCh"EHD",MEM 0040h:00DEh"EHD" ----------M004000DE-------------------------- MEM 0040h:00DEh - EHD floppy - DRIVE 3 NEEDS RECALIBARATION Size: BYTE SeeAlso: MEM 0040h:00DBh"EHD",MEM 0040h:00DCh"EHD",MEM 0040h:00DDh"EHD" ----------M004000E0-------------------------- MEM 0040h:00E0h - Phoenix 386 BIOS - DRIVE PARAMETER TABLE FOR FIRST HARD DISK Size: 16 BYTEs Note: this area is used to store the driver parameter table for the first hard disk if it has been setup as the user-configurable "type 47" ----------M004000E3-------------------------- MEM 0040h:00E3h - EHD floppy - DRIVE 0 DISKETTE TYPE (from jumpers) Size: BYTE SeeAlso: MEM 0040h:00E4h,MEM 0040h:00E5h"EHD",MEM 0040h:00E6h"EHD" (Table M050) Values for EHD floppy diskette type: 01h undefined by diskette change (360K) 02h 1.2M 03h 720K 04h 1.44M 05h 2.88M ----------M004000E4-------------------------- MEM 0040h:00E4h - EHD floppy - DRIVE 1 DISKETTE TYPE (from jumpers) Size: BYTE SeeAlso: MEM 0040h:00E3h,MEM 0040h:00E5h"EHD",MEM 0040h:00E6h"EHD" ----------M004000E5-------------------------- MEM 0040h:00E5h - EHD floppy - DRIVE 2 DISKETTE TYPE (from jumpers) Size: BYTE SeeAlso: MEM 0040h:00E3h,MEM 0040h:00E4h"EHD",MEM 0040h:00E6h"EHD" ----------M004000E6-------------------------- MEM 0040h:00E6h - EHD floppy - DRIVE 3 DISKETTE TYPE (from jumpers) Size: BYTE SeeAlso: MEM 0040h:00E3h,MEM 0040h:00E4h"EHD",MEM 0040h:00E5h"EHD" ----------M004000EA-------------------------- MEM 0040h:00EAh - Omti controller - SEGMENT OF EXTENDED BIOS DATA AREA??? Size: WORD Note: drive parameter tables stored in specified segment ----------M004000EC-------------------------- MEM 0040h:00ECh - Dell 4xxDE BIOS A11 - LOOP COUNT FOR DELAYS Size: WORD ----------M004000F0-------------------------- MEM 0040h:00F0h - INTRA-APPLICATION COMMUNICATION AREA Size: 16 BYTEs ----------M00500000-------------------------- MEM 0050h:0000h - PRINT-SCREEN STATUS Size: BYTE --------J-M00500001-------------------------- MEM 0050h:0001h - NEC PC-9800 series - SCREEN MODE Size: BYTE Note: if bit 3 set, the screen is in high-resolution mode ----------M00500004-------------------------- MEM 0050h:0004h - MS-DOS - LOGICAL DRIVE FOR SINGLE-FLOPPY SYSTEM (A: / B:) Size: BYTE ----------M0050000E-------------------------- MEM 0050h:000Eh - STATE OF BREAK CHECKING AT START OF BASICA.COM EXECUTION Size: BYTE ----------M0050000F-------------------------- MEM 0050h:000Fh - BASICA VERSION FLAG Size: BYTE Note: this byte contains the value 02h if BASICA v2.10 is running ----------M00500010-------------------------- MEM 0050h:0010h - POINTER TO BASIC DATA SEGMENT Size: WORD ----------M00500012-------------------------- MEM 0050h:0012h - INT 08 VECTOR AT START OF BASICA.COM EXECUTION Size: DWORD ----------M00500016-------------------------- MEM 0050h:0016h - INT 1B VECTOR AT START OF BASICA.COM EXECUTION Size: DWORD ----------M0050001A-------------------------- MEM 0050h:001Ah - INT 24 VECTOR AT START OF BASICA.COM EXECUTION Size: DWORD ----------M00600000-------------------------- MEM 0060h:0000h - DOS SCRATCH SPACE Size: 256 BYTEs Note: used during DOS 2+ boot process ----------M00700000-------------------------- MEM 0070h:0000h - DOS 2+ IO.SYS LOAD ADDRESS ----------m80C00000-------------------------- MEM 80C00000h - Compaq Deskpro 386 system memory board register Size: BYTE 80C00000 R Diagnostics register (see #M051) 80C00000 W RAM relocation register (see #M052) Bitfields for Compaq Deskpro 386 diagnostics register: Bit(s) Description (Table M051) 7 =0 memory expansion board is installed 6 =0 second 1 MB of system memory board is installed 5-4 base memory 00 set to 640 KB 01 invalid 10 set to 512 KB 11 set to 256 KB 3 parity correct in byte 3 2 parity correct in byte 2 1 parity correct in byte 1 0 parity correct in byte 0 (in 32-bit double word) SeeAlso: #M052 Bitfields for Compaq Deskpro 386 RAM relocation register: Bit(s) Description (Table M052) 7-2 reserved, always write 1's. 1 =0 Write-protect 128-Kbyte RAM at FE0000. =1 Do not write-protect RAM at FE0000. 0 =0 Relocate 128-Kbyte block at FE0000 to address 0E0000 =1 128-Kbyte RAM is addressed only at FE0000. SeeAlso: #M051 ----------MA0000000-------------------------- MEM A000h:0000h - EGA+ GRAPHICS BUFFER Size: 65536 BYTEs ----------MB0000000-------------------------- MEM B000h:0000h - MDA TEXT BUFFER Size: 4096 BYTEs ----------MB0000000-------------------------- MEM B000h:0000h - HGC+ RAMFont-MODE TEXT BUFFER Size: 16384 BYTEs Note: in RAMFont Mode 1, the memory is filled with the usual character/attribute pairs; in RAMFont Mode 2, four bits of each 'attribute' byte is used to provide 12 bits for specifying the character ----------MB0000000-------------------------- MEM B000h:0000h - HGC GRAPHICS BUFFER (PAGE 0) Size: 32768 BYTEs ----------MB4000000-------------------------- MEM B400h:0000h - HGC+ RAMFont BUFFER Size: 4096 BYTEs Notes: apparently write-only RAMFont Mode 1: 256 characters (8 bits each for char and attribute) RAMFont Mode 2: 3072 characters (12 bits for char, 4 bits for attrib) each character definition is 8 pixels wide (with 9th-column duplication if appropriate) by 8-16 pixels high ----------MB8000000-------------------------- MEM B800h:0000h - CGA TEXT/GRAPHICS BUFFER Size: 16384 BYTEs --------V-MB8000000-------------------------- MEM B800h:0000h - EGA/VGA+ TEXT BUFFER Size: 32768 BYTEs --------V-MB8000000-------------------------- MEM B800h:0000h - HGC GRAPHICS BUFFER (PAGE 1) Size: 32768 BYTEs ----------MBFF00000-------------------------- MEM BFF0h:0000h - ET4000/W32 ACL accelerator Size: 169 BYTES Format of ET4000/W32 memory-mapped registers: Offset Size Description (Table M053) 00h DWORD MMU Registers: memory base pointer register 0 (see #M054) 04h DWORD MMU Registers: memory base pointer register 1 (see #M054) 08h DWORD MMU Registers: memory base pointer register 2 (see #M054) 0Ch 7 BYTEs ??? 13h BYTE MMU Registers: MMU control register (see #M055) 14h 28 BYTEs ??? 30h BYTE Non-Queued Registers: suspend/terminate 31h BYTE Non-Queued Registers: operation state (see #M056) (write-only) 32h BYTE Non-Queued Registers: sync enable 33h BYTE ??? 34h BYTE Non-Queued Registers: interrupt mask 35h BYTE Non-Queued Registers: interrupt status 36h BYTE Non-Queued Registers: ACL status (read-only) bit 1: read status (RDST) 1=ACL active, queue not empty bit 0: write status (WRST) 1=queue full 37h 73 BYTEs ??? 80h DWORD Queued Registers: pattern address (see #M057) 84h DWORD Queued Registers: source address (see #M057) 88h WORD Queued Registers: pattern Y offset (see #M058) 8Ah WORD Queued Registers: source Y offset (see #M058) 8Ch WORD Queued Registers: destination y offset (see #M058) 8Eh BYTE Queued Registers: virtual bus size 8Fh BYTE Queued Registers: X/Y direction (see #M059) 90h BYTE Queued Registers: pattern wrap (see #M060) 91h BYTE ??? 92h BYTE Queued Registers: source wrap (see #M060) 93h BYTE ??? 94h WORD Queued Registers: X position 96h WORD Queued Registers: Y position 98h WORD Queued Registers: X count (see #M061) 9Ah WORD Queued Registers: Y count (see #M061) 9Ch BYTE Queued Registers: routine control (see #M062) 9Dh BYTE Queued Registers: reload control 9Eh BYTE Queued Registers: background ROP for mixing 9Fh BYTE Queued Registers: foreground ROP for mixing A0h DWORD Queued Registers: destination address A4h DWORD Queued Registers: internal pattern address A8h DWORD Queued Registers: internal source address Bitfields for ET4000/W32 memory base pointer register: Bit(s) Description (Table M054) 31-22 reserved 21-0 memory base pointer SeeAlso: #M053 Bitfields for ET4000/W32 MMU control register: Bit(s) Description (Table M055) 7 reserved 6-4 linear address control (LAC) bit 6: MMU aperture 2 bit 5: MMU aperture 1 bit 4: MMU aperture 0 3 reserved t2-0 aperture type (APT) bit 2: MMU aperture 2 bit 1: MMU aperture 1 bit 0: MMU aperture 0 SeeAlso: #M053 Bitfields for ET4000/W32 operation state register: Bit(s) Description (Table M056) 7-4 reserved 3 restart operation after ACL-interruption 2-1 reserved 0 restore status before ACL-interruption SeeAlso: #M053 Bitfields for ET4000/W32 memory address register: Bit(s) Description (Table M057) 31-22 reserved 21-0 memory base pointer SeeAlso: #M053 Bitfields for ET4000/W32 offset register: Bit(s) Description (Table M058) 15-12 reserved 11-0 Y offset SeeAlso: #M053 Bitfields for ET4000/W32 X/Y direction register: Bit(s) Description (Table M059) 7-2 reserved 1 X direction 0 Y direction SeeAlso: #M053 Bitfields for ET4000/W32 wrap register: Bit(s) Description (Table M060) 7 reserved 6-4 pattern Y wrap 000 = 1 line 001 = 2 lines 010 = 4 lines 011 = 8 lines 100 = reserved 101 = reserved 110 = reserved 111 = no wrap 3 reserved 2-0 pattern X wrap 000 = reserved 001 = reserved 010 = 4 byte 011 = 8 byte 100 = 16 byte 101 = 32 byte 110 = 64 byte 111 = no wrap SeeAlso: #M053 Bitfields for ET4000/W32 count register: Bit(s) Description (Table M061) 15-12 reserved 11-0 pixel count SeeAlso: #M053 Bitfields for ET4000/W32 routine control register: Bit(s) Description (Table M062) 7-6 reserved 5-4 routing of CPU address (ADRO) 00 don't use CPU address 01 CPU address is destination 10 reserved 11 reserved 3 reserved 2-0 routing of CPU data (DARQ) 000 don't use CPU data 001 CPU data is source data 010 CPU data is mixed data 011 reserved 100 CPU data is x-count 101 CPU data is y-count 10x reserved SeeAlso: #M053 ----------MC0000000-------------------------- MEM C000h:0000h - VIDEO BIOS (EGA and newer) Size: varies (usually 16K-24K for EGA, 24K-32K for VGA) ----------mC0000000-------------------------- MEM C0000000h - Weitek "Abacus" math coprocessor Size: 4096 BYTEs ----------MC8000000-------------------------- MEM C800h:0000h - HARD DISK BIOS Size: varies (usually 8K or 16K) ----------MC8001C00-------------------------- MEM C800h:1C00h - IBM XGA, XGA/A - MEMORY-MAPPED REGISTERS Range: any 8K boundary within segments C000h to DFFFh Notes: The XGA memory mapped registers can be assigned to the last 1K block in in each 8K block in the range of C0000h-DFFFFh; the base offset of the 128 memory mapped lcoation for a particular XGA instance is Segment:(1C00h+instance*80h) for each XGA installed in a system (default instance is 6). The instance number may be read from the XGA's Programmable Option Select registers The XGA/A (PS/2 adapter) uses the 7KB area below the memory-mapped register area for ROM data; the XGA (PS/2 onboard) has included this area in it's video BIOS ROM. Most of the memory mapped registers are from the graphics coprocessor, while the I/O-registers are for the display controller. ----------MF0006000-------------------------- MEM F000h:6000h - IBM PC ROM BASIC Size: 32768 BYTEs --------B-MF000E000-------------------------- MEM F000h:E000h - ORIGINAL IBM PC ROM BIOS Size: 8192 BYTEs --------H-MF000FFF0-------------------------- MEM F000h:FFF0h - RESET JUMP Size: 5 BYTEs --------B-MF000FFF5-------------------------- MEM F000h:FFF5h - ASCII BIOS DATE Size: 8 BYTEs ----------MF000FFFD-------------------------- MEM F000h:FFFDh - OFTEN USED TO ENSURE CORRECT BIOS CHECKSUM Size: BYTE --------B-MF000FFFE-------------------------- MEM F000h:FFFEh - MACHINE TYPE CODE Size: BYTE SeeAlso: INT 15/AH=C0h ----------Mxxxxxxx0-------------------------- MEM xxxxh:xxx0h - Multiprocessor Specification - FLOATING POINTER STRUCTURE Range: any paragraph boundary from E000h:0000h to F000h:FFE0h Note: scan paragraph boundaries for the signature string "_MP_", followed by a valid floating pointer structure (see #M063) SeeAlso: MEM FEE00000h Format of Multiprocessor Specification Floating Pointer structure: Offset Size Description (Table M063) 00h 4 BYTEs signature "_MP_" 04h DWORD physical address of MP configuration table (see #M064) 00000000h if no configuration table 08h BYTE length of this structure in paragraphs (currently 01h) 09h BYTE revision of MP specification supported 01h = v1.1 04h = v1.4 0Ah BYTE checksum (8-bit sum of entire structure, including this byte, must equal 00h) 0Bh BYTE MP feature byte 1: system configuration type 00h: MP configuration table present nonzero: default configuration implemented by system 0Ch BYTE MP feature byte 2 bit 7: IMCR present bits 6-0: reserved (0) 0Dh 3 BYTEs MP feature bytes 3-5 (reserved, must be 00h) Format of Multiprocessor Specification configuration table header: Offset Size Description (Table M064) 00h 4 BYTEs signature "PCMP" 04h WORD length of base configuration table in bytes, including this header 06h BYTE revision of MP specification supported 01h = v1.1 04h = v1.4 07h BYTE checksum of entire base configuration table 08h 8 BYTEs OEM identifier 10h 12 BYTEs product ID 1Ch DWORD physical address to OEM-defined configuration table 00000000h if not present 20h WORD size of base OEM table in bytes (0000h if not present) 22h WORD number of entries in variable portion of base table 24h DWORD address of local APIC (see also MEM FEE0h:0020h) 28h WORD length of extended entries following end of base table (in bytes) 2Ah BYTE checksum for extended table entries (includes only extended entries following base table) 2Ch var configuration table entries (see #M065) SeeAlso: #M063 Format of Multiprocessor Specification configuration table entries: Offset Size Description (Table M065) 00h BYTE entry type code 00h processor 01h bus 02h I/O APIC 03h I/IO interrupt assignment 04h local interrupt assignment 80h system address space mapping 81h bus hierarchy descriptor 82h compatibility bus address space modifier ---processor--- 01h BYTE local APIC identifier 02h BYTE local APIC version 03h BYTE CPU flags bit 0: processor usable bit 1: bootstrap processor 04h WORD CPU type bits 11-8: CPU family bits 7-4: CPU model bits 3-0: stepping (bits 11-0 all set indicate non-Intel-compatible CPU) 06h 2 BYTEs unused 08h DWORD feature flags (as returned by Pentium CPUID instruction) 0Ch 8 BYTEs reserved ---bus--- 01h BYTE bus ID (assigned sequentially from 00h by BIOS) 02h 6 BYTEs bus type (blank-padded ASCII string) (see #M066) ---I/O APIC--- 01h BYTE APIC identifier 02h BYTE APIC version 03h BYTE I/O APIC flags bit 0: enabled bits 7-1: reserved 04h DWORD base address for APIC ---I/O,local interrupt assignment--- 01h BYTE interrupt type 00h vectored interrupt (from APIC) 01h NMI 02h system management interrupt 03h vectored interrupt (from external PIC) 02h BYTE APIC control (see #M067) 03h BYTE unused 04h BYTE source bus identifier 05h BYTE source bus IRQ 06h BYTE destination I/O APIC identifier 07h BYTE destination I/O APIC interrupt pin number ---system address space mapping--- 01h BYTE entry length (14h) 02h BYTE bus ID 03h BYTE address type (00h I/O, 01h memory, 02h prefetch) 04h QWORD starting address of region visible to bus 0Ch QWORD length of region visible to bus ---bus hierarchy descriptor--- 01h BYTE entry length (08h) 02h BYTE bus ID 03h BYTE bus information bit 0: subtractive decoding 04h BYTE ID of parent bus 05h 3 BYTEs reserved ---compatibility bus address space modifier--- 01h BYTE entry length (08h) 02h BYTE bus ID 03h BYTE address modifier bit 0: remove address ranges in predefined range list from bus's address space 04h DWORD number indicating predefined address space range to be removed 00h ISA-compatible I/O range (x100h-x3FFh and aliases) 01h VGA-compatible I/O range (x3B0h-x3BBh,x3C0h-x3DFh,aliases) SeeAlso: #M064 (Table M066) Values for Multiprocessor Specification bus name: "CBUS" Corollary CBus "CBUSII" Corollary CBus II "EISA" "FUTURE" IEEE FutureBus "INTERN" internal bus "ISA" "MBI" Multibus I "MBII" Multibus II "MCA" Microchannel "MPI" "MPSA" "NUBUS" Apple Macintosh NuBus "PCI" "PCMCIA" "TC" DEC TurboChannel "VL" VESA Local Bus "VME" VMEbus "XPRESS" Express System Bus SeeAlso: #M065 Bitfields for Multiprocessor Specification APIC control: Bit(s) Description (Table M067) 1-0 input signal polarity 00 conforms to bus specification 01 active high 10 reserved 11 active low 3-2 trigger mode 00 conforms to bus specification 01 edge-triggered 10 reserved 11 level-triggered SeeAlso: #M065 ----------mFEC00000-------------------------- MEM FEC00000h - Pentium - I/O APIC Size: 4096 BYTEs Range: the Multiprocessor Specification calls for I/O APICs to be memory- mapped on 4K boundaries between FEC00000h and FEDFC000h SeeAlso: MEM FEE00000h,MEM xxxxh:xxx0h"Multiprocessor" ----------mFEE00000-------------------------- MEM FEE00000h - Pentium - LOCAL APIC Size: 4096 BYTEs Notes: the Advanced Programmable Interrupt Controller built into multiprocessor-capable Pentiums (P54C, etc. -- basically 75MHz and faster Pentiums) maps its registers into the top of the physical address space on data reads and writes, but not on code reads; data accesses to the APIC registers do not cause external bus cycles the APIC's registers are only visible when the APIC is enabled (which occurs at CPU reset when external data lines contain proper signals) SeeAlso: MEM FEC00000h,MEM FEE00020h,MEM xxxxh:xxx0h"Multiprocessor" ----------mFEE00020-------------------------- MEM FEE00020h - Pentium - LOCAL APIC - LOCAL APIC ID REGISTER SeeAlso: MEM FEE00030h ----------mFEE00030-------------------------- MEM FEE00030h - Pentium - LOCAL APIC - LOCAL APIC VERSION REGISTER Note: read-only SeeAlso: MEM FEE00020h ----------mFEE00040-------------------------- MEM FEE00040h - Pentium - LOCAL APIC - RESERVED SeeAlso: MEM FEE00000h ----------mFEE00050-------------------------- MEM FEE00050h - Pentium - LOCAL APIC - RESERVED SeeAlso: MEM FEE00000h ----------mFEE00060-------------------------- MEM FEE00060h - Pentium - LOCAL APIC - RESERVED SeeAlso: MEM FEE00000h ----------mFEE00070-------------------------- MEM FEE00070h - Pentium - LOCAL APIC - RESERVED SeeAlso: MEM FEE00000h ----------mFEE00080-------------------------- MEM FEE00080h - Pentium - LOCAL APIC - TASK PRIORITY REGISTER (TPR) ----------mFEE00090-------------------------- MEM FEE00090h - Pentium - LOCAL APIC - ARBITRATION PRIORITY REGISTER (APR) Note: read-only ----------mFEE000A0-------------------------- MEM FEE000A0h - Pentium - LOCAL APIC - END OF INTERRUPT REGISTER (EOI) Note: write-only ----------mFEE000A0-------------------------- MEM FEE000A0h - Pentium - LOCAL APIC - PROCESSOR PRIORITY REGISTER (PPR) Note: read-only SeeAlso: MEM FEE00000h ----------mFEE000B0-------------------------- MEM FEE000B0h - Pentium - LOCAL APIC - RESERVED SeeAlso: MEM FEE00000h ----------mFEE000C0-------------------------- MEM FEE000C0h - Pentium - LOCAL APIC - REMOTE READ REGISTER Note: read-only ----------mFEE000D0-------------------------- MEM FEE000D0h - Pentium - LOCAL APIC - LOGICAL DURATION REGISTER (LDR) SeeAlso: MEM FEE00000h ----------mFEE000E0-------------------------- MEM FEE000E0h - Pentium - LOCAL APIC - DESTINATION FORMAT REGISTER (DFR) bits 27-0: read-only bits 31-28: read-write ----------mFEE000F0-------------------------- MEM FEE000F0h - Pentium - LOCAL APIC - SPURIOUS INTERRUPT VECTOR REGISTER bits 3-0, read-only bits 9-4, read/write ----------mFEE00100-------------------------- MEM FEE00100h - Pentium - LOCAL APIC - IN-SERVICE REGISTER (ISR) Size: 128 BYTEs Note: read-only SeeAlso: MEM FEE00200h ----------mFEE00180-------------------------- MEM FEE00180h - Pentium - LOCAL APIC - TRIGGER MODE REGISTER (TMR) Size: 128 BYTEs Note: read-only SeeAlso: MEM FEE00000h ----------mFEE00200-------------------------- MEM FEE00200h - Pentium - LOCAL APIC - INTERRUPT REQUEST REGISTER (IRR) Size: 128 BYTEs Note: read-only SeeAlso: MEM FEE00100h ----------mFEE00280-------------------------- MEM FEE00280h - Pentium - LOCAL APIC - ERROR STATUS REGISTER Size: 4 BYTEs Note: read-only Bitfields for Pentium APIC error status register: Bit(s) Description (Table M068) 0 send checksum error 1 receive checksum error 2 send accept error 3 receive accept error 4 reserved 5 send illegal vector 6 receive illegal vector 7 illegal register address 31-8 reserved ----------mFEE00300-------------------------- MEM FEE00300h - Pentium - LOCAL APIC - INTERRUPT COMMAND REGISTER (ICR) Size: 4 BYTEs Note: this is the low half of the 64-bit ICR SeeAlso: MEM FEE00310h,#M069 Bitfields for Pentium APIC Interrupt Command Register: Bit(s) Description (Table M069) 7-0 interrupt vector number 10-8 delivery mode (see #M070) 11 destination mode 12 delivery status (read-only) 1 = transfer pending 13 reserved 14 level (0 = INIT Level Deassert message, 1 = anything else) 15 trigger mode (1) 17-16 remote read status (read-only) 19-18 destination shorthand 00 as specified by destination field 01 self 10 all including self 11 all except self 55-20 reserved 63-56 destination for interrupt request or message SeeAlso: #M072 (Table M070) Values for Pentium APIC delivery mode: 000b fixed 001b lowest-priority 010b SMI 011b remote read 100b NMI 101b INIT 110b start up 111b reserved SeeAlso: #M069 ----------mFEE00310-------------------------- MEM FEE00310h - Pentium - LOCAL APIC - INTERRUPT COMMAND REGISTER (ICR) Size: 4 BYTEs Note: this is the high half of the 64-bit ICR SeeAlso: MEM FEE00300h,#M069 ----------mFEE00320-------------------------- MEM FEE00320h - Pentium - LOCAL APIC - LOCAL VECTOR TABLE ENTRY 0 (TIMER) Size: 4 BYTEs SeeAlso: MEM FEE00350h,MEM FEE00370h,MEM FEE003E0h,INT 70h Bitfields for Pentium APIC timer local vector entry: Bit(s) Description (Table M071) 7-0 interrupt vector number 11-8 reserved 12 delivery status (read-only) 1 = interrupt being sent to APIC 15-13 reserved 16 interrupt delivery disabled 17 timer mode (0=one-shot, 1=periodic) 31-18 reserved SeeAlso: #M073,#M072 ----------mFEE00330-------------------------- MEM FEE00330h - Pentium - LOCAL APIC - RESERVED SeeAlso: MEM FEE00000h ----------mFEE00340-------------------------- MEM FEE00340h - Pentium - LOCAL APIC - RESERVED SeeAlso: MEM FEE00000h ----------mFEE00350-------------------------- MEM FEE00350h - Pentium - LOCAL APIC - LOCAL VECTOR TABLE ENTRY 1 (LINT0) Size: 4 BYTEs SeeAlso: MEM FEE00320h,MEM FEE00360h Bitfields for Pentium APIC LINTx local vector entry: Bit(s) Description (Table M072) 7-0 interrupt vector number 10-8 delivery mode 000 fixed 100 NMI 111 external interrupt (8259A-compatibility) 11 reserved 12 delivery status (read-only) 1 = interrupt being sent to APIC 13 interrupt pin is active low 14 remote IRR 15 trigger mode 0 edge-sensitive 1 level-sensitive 16 interrupt delivery disabled 31-17 reserved SeeAlso: #M071 ----------mFEE00360-------------------------- MEM FEE00360h - Pentium - LOCAL APIC - LOCAL VECTOR TABLE ENTRY 2 (LINT1) Size: 4 BYTEs SeeAlso: MEM FEE00350h,MEM FEE00370h,#M072 ----------mFEE00370-------------------------- MEM FEE00370h - Pentium - LOCAL APIC - LOCAL VECTOR TABLE ENTRY 3 (Error) Size: 4 BYTEs SeeAlso: MEM FEE00320h,MEM FEE00370h ----------mFEE00380-------------------------- MEM FEE00380h - Pentium - LOCAL APIC - INITIAL COUNT REGISTER (ICR) TIMER Desc: timer start value, which together with the Divide Configuration Register also determines its period when periodic mode has been selected SeeAlso: MEM FEE00000h,MEM FEE00390h ----------mFEE00390-------------------------- MEM FEE00390h - Pentium - LOCAL APIC - CURRENT COUNT REGISTER (CCR) TIMER Desc: current timer count; when this value reaches zero, an interrupt is generated Note: read-only SeeAlso: MEM FEE00380h ----------mFEE003A0-------------------------- MEM FEE003A0h - Pentium - LOCAL APIC - RESERVED SeeAlso: MEM FEE00000h ----------mFEE003B0-------------------------- MEM FEE003B0h - Pentium - LOCAL APIC - RESERVED SeeAlso: MEM FEE00000h ----------mFEE003C0-------------------------- MEM FEE003C0h - Pentium - LOCAL APIC - RESERVED SeeAlso: MEM FEE00000h ----------mFEE003D0-------------------------- MEM FEE003D0h - Pentium - LOCAL APIC - RESERVED SeeAlso: MEM FEE00000h ----------mFEE003E0-------------------------- MEM FEE003E0h - Pentium - LOCAL APIC - TIMER DIVIDE CONFIGURATION REGISTER SeeAlso: MEM FEE00000h,MEM FEE00320h Bitfields for Pentium APIC timer divide configuration: Bit(s) Description (Table M073) 3,1,0 divisor 000 divide by 2 001 by 4 010 by 8 ... 110 by 128 111 by 1 2 zero (0) 31-4 reserved Note: the divisor determines the timer's time base relative to the processor clock SeeAlso: #M071 ----------MFFFF0010-------------------------- MEM FFFFh:0010h - HIGH MEMORY AREA Size: 65520 BYTEs --------------------------------------------- --------!---CONTRIBUTORS--------------------- Robin Walker ORIGINAL FILE Wim Osterholt or Wim Osterholt 2:512/56 EHD floppy = 'KEGAN 4.0M Floppy Drive Controller.', 'ACME FX4-K7tb2 v:2.5 11/5/91' Stanley Appel Matthias Paul --------!---Admin---------------------------- Highest Table Number = M073 --------!---FILELIST------------------------- Please redistribute all of the files comprising the interrupt list (listed at the beginning of the list and in INTERRUP.1ST) unmodified as a group, in a quartet of archives named INTER48A through INTER48D (preferably the original authenticated PKZIP archives), and the utility programs in a two additional archives called INTER48E.ZIP and INTER48F.ZIP This compilation is Copyright (c) 1989,1990,1991,1992,1993,1994,1995 Ralf Brown --------!---CONTACT_INFO--------------------- Internet: ralf@pobox.com (currently forwards to ralf@telerama.lm.com) UUCP: {uunet,harvard}!pobox.com!ralf FIDO: Ralf Brown 1:129/26.1 or post a message to me in the DR_DEBUG echo (I probably won't see it unless you address it to me) CIS: >INTERNET:ralf@pobox.com