Compaq 850 ROM Flashing, Upgrading, Boot Block Codes, Num Lock Cap Lock Scroll Lock, Meaning

Chapter 7 BIOS ROM

7.2ROM FLASHING

The system BIOS firmware is contained in a flash ROM device that can be re-written with BIOS code (using the ROMPAQ utility or a remote flash program) allowing easy upgrading, including changing the splash screen displayed during the POST routine.

7.2.1 UPGRADING

Upgrading the BIOS is not normally required but may be necessary if changes are made to the unit’s operating system, hard drive, or processor. All BIOS ROM upgrades are available directly from Compaq. Flashing is done either locally with a ROMPaq diskette or remotely using the network boot function (described in the section 8.3.2).

This system includes 64 KB of write-protected boot block ROM that provides a way to recover from a failed remote flashing of the system BIOS ROM. If the BIOS ROM fails the flash check, the boot block code provides the minimum amount of support necessary to allow booting the system from the diskette drive and re-flashing the system ROM with a ROMPAQ diskette. Note that if an administrator password has been set in the system the boot block will prompt for this password by illuminating the caps lock keyboard LED and displaying a message if video support is available. A PS/2 keyboard must be used during bootblock operation.

Since video may not be available during the initial boot sequence the boot block routine uses the Num Lock, Caps Lock, and Scroll Lock LEDs of the PS/2 keyboard to communicate the status of the ROM flash as follows:

Table 7-1. Boot Block Codes

Table 7-1.

Boot Block Codes

Num Lock	Cap Lock	Scroll Lock
LED	LED	LED	Meaning
Off	On	Off	Administrator password required.
On	Off	Off	Boot failed. Reset required for retry.
Off	Off	On	Flash failed.
On	On	On	Flash complete.

7-2Compaq Deskpro EXS and Workstation 300 Personal Computers

Featuring the Intel Pentium 4 Processor

First Edition - December 2000