BIOS Settings - Integrated Peripherals



This section discusses settings that control your system's 
integrated peripherals. These settings are used to enable or 
disable integrated peripheral support, and set the various 
resources they use. If in addition to the standard integrated 
peripherals (serial and parallel ports, floppy and disk drives, 
etc.) you have integrated video, sound or other devices, you 
may find controls for them in this section.


Integrated Floppy Disk Controller

This setting enables or disables the integrated floppy disk 
controller (FDC). The default for this is "Enabled". If for 
some reason you are using a plug-in floppy disk controller 
card, you will want to disable the integrated controller. 


Integrated IDE Controllers

This setting enables or disables the integrated primary and 
secondary IDE/ATA controllers. If you are using an add-in IDE 
controller card (which there is normally no need to do), or if 
you are not using IDE devices at all (for example, if you use 
SCSI devices), you can disable the built-in controller here.

On some BIOSes a single setting controls both the primary and 
secondary channels; the options in this case are "Disabled", 
"Primary", "Secondary" and "Both". Other BIOSes have two separate 
"Enabled"/"Disabled" settings, one for the primary channel and 
one for the secondary channel.

The default on most systems is to enable both IDE channels. This 
is usually an acceptable setting for most PCs, but some systems 
can exhibit strange behavior if the secondary IDE channel is 
enabled but there are no drives on it; for example, Windows 95 
may try to set up a drive controller device on the secondary 
channel and then get confused when nothing is on it. It is 
therefore prudent to disable the secondary IDE channel unless 
you are using it. This will also free up the IRQ used by the 
secondary channel (IRQ15) for use with other devices, if you 
need it. See this section in the Optimization Guide for ideas 
about optimizing IDE channel setup .


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). For 
each serial port setting you will typically find these: 

	3F8/IRQ4 (COM1): Sets the serial port to the I/O address 
	and IRQ normally used by COM1. This is usually the 
	default for the first serial port. 

	2F8/IRQ3 (COM2): Sets the serial port to the I/O address 
	and IRQ normally used by COM2. This is usually the 
	default for the second serial port. 

	3E8/IRQ4 (COM3): Sets the serial port to the I/O address 
	and IRQ normally used by COM3. 

	2E8/IRQ3 (COM4): Sets the serial port to the I/O address 
	and IRQ normally used by COM4. 

	(Other options): Some systems now let you select other 
	IRQs to assign to the onboard ports, to use if you are 
	trying to avoid a resource conflict. 

	Disabled: Disables the 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.

	Note: This setting is either locked out or ignored if 
the parallel port is disabled.


Parallel Port ECP DMA Channel

If your system supports ECP parallel port mode and you have the 
port set to use ECP, you must use this setting to assign a DMA 
channel for use by the port. The usual options are "DMA 1" 
and "DMA 3".

	Note: This setting is either locked out or ignored if 
the parallel port is disabled, or if the parallel port mode is 
not set to ECP.

	Warning: Some BIOSes allow this to be set to DMA channel 
2 as well, which is normally reserved for the floppy disks. This 
will often create a resource conflict if chosen.


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").
