Technical The BIOS and CMOS Integrated Peripherals

Integrated Peripherals

Below are explainations for the fields and options found on this page of modern motherboards.

Onboard IDE -1 Controller

This option enables or disables the first IDE channel of the motherboard's onboard IDE controller. If using a SCSI or second IDE expansion card the first IDE channel can be disabled to free up an IRQ

Enabled: Uses the onboard Primary IDE channel.
Disabled: Mainly used for troubleshooting.

Onboard IDE -2 Controller

This option enables or disables the secondary IDE channel of the motherboard's onboard IDE controller. If using a SCSI or second IDE expansion card the first IDE channel can be disabled to free up an IRQ

Enabled: Uses the onboard secondary IDE channel.
Disabled: Mainly used for troubleshooting.

Master / Slave PIO Mode

This field sets the PIO (Programmed Input/Output) mode for the two IDE devices (Master and Slave) attached to an IDE channel.

Auto: BIOS auto detects the IDE drive PIO mode.
0,1,2,3,4: Used mainly for troubleshooting.

It is important that the PIO setting matches the hard drive or corruption of data may result.

Master / Slave UltraDMA

This field sets the UDMA (UltraDMA) mode for the two IDE devices (Master and Slave) attached to an IDE channel.

Auto: BIOS auto detects the IDE drive UDMA mode.
Disabled: Used mainly for troubleshooting.

In order for any DMA modes to work in Win9x, tick the DMA checkbox in the properties sheet of the IDE drive.

USB Controller

This option enables or disables IRQ allocation for the USB (Universal Serial Bus).

Disabled: If there are no USB devices this will free up an IRQ.
Enabled: If using a USB device. Enable this option when installing Win9x OS to correctly install AGP support. Can be disabled once Windows is configured.

USB Keyboard Support

This field enables or disables support for a USB keyboard.

Disabled: If there is no USB keyboard.
Enabled: If using a USB keyboard.

Init Display First

This option enables booting the system using the AGP graphics card or the PCI graphics card if there is more than one graphics card. If there is only one graphics card, then the BIOS will detect the card and boot up normally, .

PCI: Select this option to boot from the PCI graphics card first.
AGP: Boot from an AGP graphics card first.

Power On Function

This field sets the how the computer will switch on.

Button On: Will only start up with the button / switch on the case.
Keyboard 98: Uses the keyboard wakeup key to start the system. This option also needs the Windows 98 OS installed on the computer.
Hot Key: For keyboards that do not have a wakeup key. Choose from CTRL-F1 to CTRL F12.

Onboard FDD Controller

This field sets the option to enable or disable the onboard floppy drive controller. If you are using a floppy drive connected to the onboard controller, then the floppy disk drive controller must be enabled.

Enabled: Use onboard floppy disk drive controller.
Disabled. If there is no floppy drive on the system. Could free up an IRQ.

Onboard Serial Ports 1/2

This field disables or manually sets the I/O address and IRQ for the serial ports.

Auto: The BIOS will determine the best settings for the port.
Disabled: If there is no devices attached to the selected serial port. Could free an IRQ.
2E8/IRQ3-3F8/IRQ10: Usually for diagnostic purposes or if the serial port is using an IRQ required by another device in the system.

Onboard IR Function

This option sets the Infra Red mode a connected external device. If the onboard serial port 2 is disabled this option may not appear.

IrDA HPSIR: Infrared Data Association Protocol. Uses things like collision, addressing and retransmission.
ASK IR: Amplitude Shift Keyed IR mode
Disabled: No support for IR modes.

Duplex Select

This options sets the transmission mode of the IR port.

Full duplex: Allows simultaneous two-way transmission.
Half duplex: Allows transmission in one direction at any one time only.

Onboard Parallel Port

This field allows selection the I/O address and IRQ for the onboard parallel port.

378h/IRQ7-3BCh/IRQ7: Sets the parallel port to another IRQ and I/O address.
Disabled: If there are no devices attached to the parallel port. May free up an IRQ.

Parallel Port Mode

This field is used to set the transfer mode for the onboard parallel port. If the parallel port is disabled this option may not be available.

ECP: Uses the DMA protocol to provide symmetric bi-directional communication.
EPP: Uses existing parallel port signals to provide asymmetric bi-directional communication.
SPP: Will work with all parallel port devices but is very slow.
ECP+EPP: The parallel device will be able to use either of these devices.

ECP Mode Use DMA

This feature is used to select the DMA channel of the Parallel port. If the parallel port is disabled, this option may not appear.

DMA 1: Default setting should work on most systems.
DMA 3: Mainly for diagnostic purposes. If a card needs the default DMA may option can be used.

EPP Mode Select

This field sets the version of EPP or ECP+EPP to use. If you do not enable one of them in the Parallel Port Mode, this option will usually not appear, or be greyed out. For faster performance use EPP 1.9. For compatability issues use EPP 1.7

EPP 1.7: Some older devices won't cope with the newer signal, so enable this option if you have issues.
EPP1.9: This should be the default setting, which allows for longer cabling and fixs the timeout bug with EPP 1.7

Plug And Play Set-up

ACPI Explained