MEM 0000h:0400h - 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. DATA AREA
MEM 0040h:000Eh - SEGMENT OF EXTENDED 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. DATA SEGMENT (PS/2IBM PS/2, any model, newer BIOSes)
MEM 0040h:0010h - INSTALLED HARDWARE
MEM 0040h:0012h - Convertible - POSTsee Power-On Self-Test STATUS
MEM 0040h:0013h - BASE MEMORY SIZE IN KBYTES
MEM 0040h:003Eh - DISKETTE - RECALIBRATE STATUS
MEM 0040h:003Fh - DISKETTE - MOTOR STATUS
MEM 0040h:0040h - DISKETTE - MOTOR TURN-OFF TIMEOUT COUNT
MEM 0040h:0041h - DISKETTE - LAST OPERATION STATUS
MEM 0040h:0042h - DISK - FLOPPY/HARD DRIVE STATUS/COMMAND BYTES
MEM 0040h:0043h - DISK CONTROLLER STATUS REGISTER 1
MEM 0040h:0044h - DISK CONTROLLER STATUS REGISTER 2
MEM 0040h:0074h - FIXED DISK LAST OPERATION STATUS (except ESDI(Enhanced Small Device Interface) A disk drive interface type which was briefly popular before IDE took over. An ESDI drive can transfer data between the drive and controller at 10, 15, or 20 megabits per second, which is faster than an MFM or RLL controller but slower than what is possible with an IDE or SCSI drive. See also IDE. drives)
MEM 0040h:0075h - FIXED DISK - NUMBER OF FIXED DISK DRIVES
MEM 0040h:0076h - FIXED DISK - CONTROL BYTE {IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. documented only for XTIBM PC XT}
MEM 0040h:0077h - FIXED DISK - I/O port offset {IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. documented only for XTIBM PC XT}
MEM 0040h:0078h - PARALLEL DEVICE 1 TIME-OUT COUNTER
MEM 0040h:0079h - PARALLEL DEVICE 2 TIME-OUT COUNTER
MEM 0040h:007Ah - PARALLEL DEVICE 3 TIME-OUT COUNTER
MEM 0040h:007Bh - PARALLEL DEVICE 4 TIME-OUT COUNTER (pre-PS, PSIBM PS/2, any model Models 25,30)
MEM 0040h:007Ch - SERIAL DEVICE 1 TIMEOUT COUNTER
MEM 0040h:007Dh - SERIAL DEVICE 2 TIMEOUT COUNTER
MEM 0040h:007Eh - SERIAL DEVICE 3 TIMEOUT COUNTER
MEM 0040h:007Fh - SERIAL DEVICE 4 TIMEOUT COUNTER
MEM 0040h:008Bh - DISKETTE MEDIA CONTROL
MEM 0040h:008Ch - FIXED DISK - CONTROLLER STATUS [not XTIBM PC XT]
MEM 0040h:008Dh - FIXED DISK - CONTROLLER ERROR STATUS [not XTIBM PC XT]
MEM 0040h:008Eh - FIXED DISK - INTERRUPT CONTROL [not XTIBM PC XT]
MEM 0040h:008Fh - DISKETTE CONTROLLER INFORMATION [not XTIBM PC XT] {undocumentedInformation about a product which is not publicly available from the manufacturer, and must be determined by reverse-engineering (disassembly, trial-and-error, etc.). Undocumented information tends to change -- often dramatically -- between successive revisions of a product, since the manufacturer has no obligation to maintain compatibility in behavior which is not explicitly stated.}
MEM 0040h:0090h - DISKETTE DRIVE 0 MEDIA STATE
MEM 0040h:0091h - DISKETTE DRIVE 1 MEDIA STATE
MEM 0040h:0092h - DISKETTE DRIVE 0 MEDIA STATE ATIBM PC AT START OF OPERATION {undocumentedInformation about a product which is not publicly available from the manufacturer, and must be determined by reverse-engineering (disassembly, trial-and-error, etc.). Undocumented information tends to change -- often dramatically -- between successive revisions of a product, since the manufacturer has no obligation to maintain compatibility in behavior which is not explicitly stated.}
MEM 0040h:0093h - DISKETTE DRIVE 1 MEDIA STATE ATIBM PC AT START OF OPERATION {undocumentedInformation about a product which is not publicly available from the manufacturer, and must be determined by reverse-engineering (disassembly, trial-and-error, etc.). Undocumented information tends to change -- often dramatically -- between successive revisions of a product, since the manufacturer has no obligation to maintain compatibility in behavior which is not explicitly stated.}
MEM 0040h:0094h - DISKETTE DRIVE 0 CURRENT TRACK NUMBER
MEM 0040h:0095h - DISKETTE DRIVE 1 CURRENT TRACK NUMBER
MEM 0040h:0098h - TIMER2 (ATIBM PC AT, PSIBM PS/2, any model exc Mod 30) - PTR TO USER WAIT-COMPLETE FLAG
MEM 0040h:009Ch - TIMER2 (ATIBM PC AT, PSIBM PS/2, any model exc Mod 30) - USER WAIT COUNT IN MICROSECONDS
MEM 0040h:00A0h - TIMER2 (ATIBM PC AT, PSIBM PS/2, any model exc Mod 30) - WAIT ACTIVE FLAG
MEM 0050h:0000h - PRINT-SCREEN STATUS
MEM C800h:0000h - HARD DISK 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.
MEM F000h:2DC5h - IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. ATIBM PC AT SIGNATURE
MEM F000h:E000h - ORIGINAL IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. PCIBM PC ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. 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.
MEM F000h:FFF5h - ASCII 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. DATE
MEM F000h:FFFDh - OFTEN USED TO ENSURE CORRECT 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. CHECKSUM
MEM F000h:FFFEh - MACHINE TYPE CODE
MEM F000h:xxxxh - AWARD Flash Hook