Chapter 7 Bios Rom; Introduction - Compaq Deskpro EP 6233 Technical Reference Manual

Chapter 7
BIOS ROM

7. Chapter 7 BIOS ROM

7.1

INTRODUCTION

The Basic Input/Output System (BIOS) of the computer is a collection of machine language
programs stored as firmware in read-only memory (ROM). The BIOS ROM includes such
functions as Power-On Self Test (POST), PCI device initialization, Plug 'n Play support, and
power management support including APM 1.2, and ACPI. The BIOS ROM also contains the
Setup utility that is accessible through the F10 key. This system is DMI-compliant and includes
SMBIOS v2.1 support. This chapter includes the following topics:
Boot Functions (7.2)
Memory detection/configuration (7.3) page 7-3
Client management support (7.4)
PnP support (7.5)
Power management functions (7.6)
USB legacy support (7.7)
BIOS upgrading (7.8)
The firmware contained in the BIOS ROM supports the following operating systems:
DOS 6.2
Windows 3.1
Windows for Workgroups 3.11
Windows 95
Windows NT 3.5
OS/2 ver 2.1
OS/2 Warp
SCO Unix
The microprocessor accesses the BIOS ROM as a 128-KB block from E0000h to FFFFFh. The
BIOS data is shadowed in a 64-KB block in the upper memory area. The BIOS segments are
dynamically paged in and out of the 64-KB block as they are needed.
NOTE: This chapter focuses on special features and aspects of BIOS unique to this
particular system. For detailed information regarding the BIOS, refer to the Compaq
Basic Input/Output System Technical Reference Guide.
page 7-2
page 7-4
page 7-19
page 7-21
page 7-24
page 7-24
Compa Deskpro EP Series of Personal Computers
First Edition- April 1998
Technical Reference Guide
7-1