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Devices on the isa bus – HP Vectra VL 5/xxx Series 5 User Manual

Page 37

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37

2 System Board

Devices on the ISA Bus

Devices on the ISA Bus

Super I/O Controller

The Super I/O chip (37C932) is part of the chip set, and is described on
page 26.

The computer is supplied with a Logitech 2-button mouse, and a C3758A
keyboard with the following features:

❒ Space bar power on, to start the computer from the Off state (if

power on

from keyboard

is enabled in the Setup program).

❒ Windows key (next to the

keys), which has the same effect as

clicking the “Start” button on the Windows 95 task bar.

❒ Pull-down key (next to the right

key), which has the same effect as

clicking the right mouse button.

Serial EEPROM

The computer uses 4 Kbit of Serial EEPROM implemented within a single
512 K ✕ 8-bit ROM chip. Serial EEPROM is ROM in which one byte at a time
can be returned to its unprogrammed state by the application of appropriate
electrical signals. In effect, it can be made to behave like very slow, non-
volatile RAM. It is used for storing the contents of the CMOS memory (the
tatoo string, the serial number, and the parameter settings for the Setup
program), even during long periods of the computer being unplugged from
the mains supply.

When installing a new system board, the Serial EEPROM 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 computer.

ISA Device

Index

Data

Super I/O

15Ch

15Dh

Little Ben (HP ASIC)

496h

497h