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Bios addresses – HP Vectra VL 5/xxx Series 5 User Manual

Page 79

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4 Summary of the HP/Phoenix BIOS

BIOS Addresses

BIOS Addresses

This section provides a summary of the main features of the HP system
BIOS. This is software that provides an interface between the computer
hardware and the operating system.

System Memory Map

Reserved memory used by accessory boards must be located in the area
from C8000h to EFFFFh.

Product Identification

The reserved addresses in the 64 KB BIOS ROM data area, which contain
various product identification and BIOS identification strings, are no longer
accessed directly. Instead, the information is obtained from utilities in the
Desk Management Interface (DMI).

0 - 3FFh

Interrupt vector table

640 KB: The addresses
0-9FFFFh are collectively
known as the Base
memory area

400h - 4FFh

BIOS data area

500h - 9EFFFh

9F000h - 9FFFFh

Extended BIOS data area

A0000h - BFFFFh

128 KB: Video memory area

C0000h - C7FFFh

32 KB: Video BIOS area

C8000h - D7FFFh

64 KB: available for accessory boards
(used by the boot ROM, if configured in the Setup program)

D8000h - EFFFFh

96 KB: available after the POST (for upper memory block, UMB, for example)

F0000h - FFFFFh

64 KB: System BIOS area

100000h - FFFFFFFFh

1 MB plus: Extended memory