Hardware Reference
In-Depth Information
•
RAID (Redundant Array of Independent Disks) cards
—Adapters that enable you
to attach multiple drives and array them in different ways to improve reliability, re-
dundancy, and performance. These cards require an onboard BIOS to enable the array
to be bootable.
•
Network cards
—Those that support booting directly from a file server have what is
usually called a
boot ROM
or
IPL (initial program load) ROM
onboard. This enables
PCs to be configured on a local area network (LAN) as diskless workstations—also
called
Net PCs
,
NCs
(network computers),
thin clients
, or even
smart terminals
.
•
ATA/Serial ATA (SATA) or floppy upgrade boards
—Boards that enable you to at-
tach more or different types of drives than what is typically supported by the mother-
board alone. These cards require an onboard BIOS to enable these drives to be boot-
able.
•
Y2K boards
—Boards that incorporate BIOS fixes to update the century byte in the
CMOS RAM. These boards have a small driver contained in the BIOS that monitors
the year byte for a change from 99 to 00. When this is detected, the driver updates the
century byte from 19 to 20, correcting a flaw in some older motherboard ROM BIOS.
Upgrading the BIOS
Motherboard manufacturers tailor the BIOS code to the specific hardware on each board.
This is what makes upgrading a BIOS somewhat problematic; the BIOS usually resides
in one or more ROM chips on the motherboard and contains code specific to that mother-
board model or revision. In other words, you must get your BIOS upgrades from your
motherboard manufacturer or from a BIOS upgrade company that supports the mother-
board you have, rather than directly from the original core BIOS developer.
Although most BIOS upgrades are done to fix bugs or problems, you must often upgrade
the BIOS to take advantage of some other upgrade. For example, a BIOS upgrade often
adds support for newer processors, larger internal hard drives, bootable optical and USB
drives, faster booting, and more.
Part of the PC 2001 standard published by Intel and Microsoft requires something called
Fast POST
to be supported. Fast POST means that the time it takes from turning on the
poweruntilthesystemstartsbootingfromdiskmustbe12secondsorless.Thistimelimit
includes the initialization of the keyboard, video card, and ATA bus. For systems contain-
ing adapters with onboard ROMs, an additional 4 seconds are allowed per ROM. Intel
calls the Fast POST feature
Rapid BIOS Boot (RBB)
and is supported in all its mother-
boards from 2001 and beyond—some of which can begin booting from power-on in 6
seconds or less.
