SYSTEM ROM
The PC uses 256 KB of 200ns, Flash EEPROM implemented within a single 256 K 5 8-bit ROM
chip. This is a ROM that can be returned to its unprogrammed state by the application of
appropriate electrical signals to its pins, and hence can then be reprogrammed with the latest
upgrade firmware.
The System ROM contains the system BIOS (including the boot code, the ISA and PCI
initialization, RPO, DMI, the
Setup program and the Power-On Self-Test routines, plus their
error messages). These are summarized in Chapters 4 to 6.
Updating the System ROM
The System ROM can be updated with the latest BIOS firmware. This can be ordered from HP
or downloaded from one of HP’s online services. (For more information on HP’s online
services, refer to the Hewlett-Packard Support and Information Services chapter in the User’s
Guide that was supplied with the computer.)
The System ROM is updated by running the PHLASH utility, PHLASH.EXE, which is supplied
with the BIOS upgrade file, GW07xx.FUL, and the system definition file, platform.bin. You
must specify the
model number of the PC since the utility which is supplied for a different
model cannot be used with this one. It must be run from diskette.
Before flashing, it is necessary to disable the “Secure Mode” switch on the system switches,
and to type in the System Administrator’s Password when starting up the computer. The PCI
and PnP information is erased in the process. The procedure for performing the update, using
a command of the form “PHLASH GW07xx.FUL”, is given in the
User’s Guide that is supplied
with the computer.
Do not switch off the computer until the system BIOS update procedure has completed,
successfully or not, since irrecoverable damage to the ROM may be caused. While updating
the flash ROM, the power supply switch and the reset button are disabled to prevent accidental
interruption of the flash programming process.
When installing a new system board, the ROM will have a blank serial number field. This will
be detected automatically by the BIOS, which will then prompt the user to enter the serial
number which is printed on the identification label on the back of the PC (see the diagram in
Chapter 1).
Error Diagnostics and Suggested Corrective Actions
The programs and data in the system ROM are accompanied by a check-sum code. If any of
the programs or data ever become corrupted, the check-sum will not correspond with the
contents of the ROM, and the appropriate part of the POST routine will attempt to report the
error:
Cannot display error messages
Flash ROM may be defective
The suggested corrective action is to reprogram the system ROM by running the same utility as
is normally used for upgrading it.
