Access CMOS settings using Esc, Del, F1, F2
or F10
For EISA or MCA the reference or setup disk
comes with the machine
Date
The system date. Make sure that you enter it
in the correct format; normally this is mm/dd/yy in North America, but
may vary elsewhere.
Time
The system time. Most systems require this to
be entered using a 24-hour clock.
Daylight Savings
If your BIOS has this setting, enabling it will
forward the time by one hour on the first Sunday in April, and drop it
back by one hour on the last Sunday in October. The default value is usually
"Enabled".
IDE Primary/Slave Master
Hard disk parameters are entered for the primary
master/slave IDE/ATA device. The default setting for this on a system with
IDE autodetection, is usually "Auto".
Note: Some older systems only have places
for two drives' parameters to be entered; often in this case they just
call them "Drive C" and "Drive D".
IDE Secondary Master
A secondary controller can support another 2
drives
Floppy Drive A/B - The choices normally
are:
1.44 MB: A normal 3.5" drive.
1.2 MB: A normal 5.25" drive.
2.88 MB: A high-density 3.5" drive, found
on some newer systems.
720 KB: A low-density 3.5" drive.
360 KB: A low-density 5.25" drive.
Video Display Type
This is the standard type of the display you
are using; almost always this should be set to either "VGA" or "VGA/EGA"
for a modern PC, if you are using any sort of VGA or SVGA card (which is
basically every PC made in the nineties.) This is also usually the default
value.
Advanced Settings
System Cache - There are many layers of cache
in a modern PC. Each layer is closer to the processor and faster than the
layer below it. Each layer also caches the layers below it, due to its
increased speed relative to the lower levels:
Level
Devices Cached
Level 1 Cache
Level 2 Cache, System RAM, Hard Disk / CD-ROM
Level 2 Cache
System RAM, Hard Disk / CD-ROM
System RAM
Hard Disk / CD-ROM
Hard Disk / CD-ROM
--
Internal cache
Level 1 (L1) or primary cache is the fastest
memory on the PC. It is built directly into the processor itself. This
cache is very small, generally from 8 KB to 64 KB, but it is extremely
fast; it runs at the same speed as the processor.
External cache
The level 2 (L2) cache is a secondary cache
to the level 1 cache, and is larger and slightly slower. It is used to
catch recent accesses that are not caught by the level 1 cache, and is
usually 64 KB to 2 MB in size. Level 2 cache is usually found either on
the motherboard or a daughterboard that inserts into the motherboard.
Boot Sequence
This setting controls the order that the
BIOS uses to look for a boot device from which to load the operating system
during the DOS boot process. Newer systems will allow you to boot from
the CD-ROM as well; in this case there will be six different combinations
listed. The default will normally be "A:, C:,CD-ROM".
Quick Power On Self Test / Quick Boot
Enabling this setting will cause the BIOS power-on
self test routine to skip some of its tests during bootup. One of the key
things this setting usually does when enabled is cause the POST to skip
checking all of extended memory for errors.
Power On Delay / Boot Delay
If you have the combination of a PC that boots
up quickly, and a hard disk that takes a relatively long time to spin up,
your BIOS may start trying to boot the operating system before the hard
disk is read.
Boot Up Numlock Status
This setting, when enabled, automatically turns
on your NumLock key when the system is booted. Most systems default this
to enabled.
Swap Floppy Drives
A useful feature for those machines that use
two floppy drives, when enabled this swaps the A: and B: drives.
Floppy Drive Seek
Causes the BIOS to search for floppy disk drives
at boot time.
Keyboard Installed
Some BIOSes let you specify explicitly if there
is a keyboard in the system.
ROM Shadowing
When shadowing of a region of memory is enabled,
at boot time the BIOS copies the contents of the ROM into the underlying
RAM, write-protects the RAM and then disables the ROM. To the system the
shadow RAM appears as if it is ROM, and it is also write-protected the
way ROM is. This write-protection is important to remember, because if
you enable shadowing of memory addresses that are being used for RAM, the
device using it will cease to function when the RAM can no longer be written
to (it is locked out by the shadowing).
Video BIOS Shadowing
This parameter, when enabled, turns on BIOS
ROM shadowing for the block of memory normally used for standard VGA video
ROM code, which is C0000 to C7FFF (32K).
System BIOS Shadow
When enabled, this parameter turns on BIOS ROM
shadowing for the block of memory that contains your system BIOS. This
is normally F0000 to FFFFF (64K)
BIOS Settings - Integrated Peripherals
These settings control your system's integrated
peripherals. These settings are used to enable or disable integrated peripheral
support, and set the various resources they use.
Integrated Floppy Disk Controller
This setting enables or disables the integrated
floppy disk controller (FDC). The default for this is "Enabled".
Integrated IDE Controllers
This setting enables or disables the integrated
primary and secondary IDE/ATA controllers. On some BIOSes a single setting
controls both the primary and secondary channels; the options in this case
are "Disabled".
Integrated Serial Port 1 / Serial Port 2
This setting lets you specify the resources
for the first and second serial ports on the motherboard. The exact name
used for the various options varies (some call them "COM1", "COM2", etc.
while others just list the I/O address and IRQ options).
3F8/IRQ4 (COM1): the first serial port.
2F8/IRQ3 (COM2): the second serial port.
3E8/IRQ4 (COM3): the third serial port.
2E8/IRQ3 (COM4): the fourth serial port.
Normally you will set the first serial port
to the resource settings for COM1, and the second to COM2. If you are using
an internal modem and you want it to be set up by your system as COM2,
the easiest way to do this without generating any conflicts is to disable
the second serial port here, to prevent interference.
Integrated Parallel Port
This setting lets you specify the resources
for the integrated parallel port. On most systems you are allowed to choose
one of the typical resource settings allocated to parallel ports, or to
disable the port:
378/IRQ7 (LPT1): Sets the parallel port
to the I/O address and IRQ normally used by LPT1. This is usually the default.
278/IRQ5 (LPT2): Sets the parallel port
to the I/O address and IRQ normally used by LPT2.
Disabled: Disables the integrated parallel
port.
Integrated Parallel Port Mode
Parallel ports have several different modes
of operation. The original parallel ports were used only for one-way communication
from the PC to the printer; newer ones include bi-directional communication
and other abilities. The normal choices for this setting are:
SPP: Sets
the parallel port to function as a Standard Parallel Port. This is the
default (and slowest) option.
EPP: Sets the parallel port to Enhanced
Parallel Port mode. Sometimes also called "Bi-directional"
ECP: Sets the parallel port up as an
Enhanced Capabilities Port. This setting requires the use of a DMA channel,
usually specified through another BIOS setting.
Generally speaking, you will usually want to
use EPP or ECP. ECP has enhanced performance but greater compatibility
problems, overall. I usually use EPP.
PS/2 Mouse Enable
On systems that support a PS/2 style mouse,
this setting enables or disables this port. If you are using the port you
should enable this, otherwise you should disable it so that the interrupt
reserved for the PS/2 mouse (IRQ12) can be used for another purpose. Some
systems have an "Auto" setting for this parameter, which is really ideal,
since it will only enable PS/2 support if you actually have one connected.
USB Enable
Use this setting to enable USB (Universal Serial
Bus) devices on motherboards that support USB. If you are not using USB,
leave this setting at its default ("Disabled").