XEN-PC (P2) Motherboard (Rev 1.6.1)

RAM CONFIGURATION (only the following configurations are supported)

Ethernet Options

Hard Drives

JUMPER SETTINGS

Jumper numbering looking from the front of the machine.

ECP DMA Channel

VGA Reset

Password Setting

BIOS Vendor

VGA Select

On-board SMC665

On-board VGA (CL543x)

System Clock

VESA/PCI Selection

CPU Type

System Speed

On-board Local Bus IDE

HDD I/O Address

Cache Data Sizing

DX4-100 Clock Mul.

External SMM

Reset / External SMM

AMD CPU Clock Mul.

CPU VCC

ADDITIONAL OPTIONS

REAR PANEL

CMOS

To discharge CMOS remove the Lithium battery as shown below. To enter CMOS Setup press the CTRL-ALT-ESC keys.

LITHIUM BATTERY
This battery has a life of 3 years, and is user replaceable when discharged.
The XEN-PC uses a 3V lithium battery, used in calculators and other small, battery powered electronic items. The battery used in the XEN-PC is a BP2335 or equivalent.

INTERRUPTS, DMA, MEMORY and I/O PORTS

Interrupts
DMA
Memory Map
I/O Ports

Interrupts (IRQ)

DMA Channels

Memory Map

I/O Ports

LED Cable Positions

Using the BIOS Setup Utility

When you invoke BIOS Setup the main menu contains several choices as shown below:

Basic System Configuration uses a two page screen that allows you to modify settings for date and time, drive types, serial port characteristics and so on.

Date
The BIOS Setup utility shows the system date in month/day/year format.

To alter the date:
1. Use the UP ARROW and DOWN ARROW keys to select the field you want to change (month, day or year).
2. Use the LEFT ARROW and RIGHT ARROW keys to scroll through the field's possible values until you reach the correct one.

Once the correct date is set you should not need to set it again. The computer accounts for leap years automatically.

Time
The BIOS Setup utility shows the system time in 24-hour hours:minutes:seconds format.

To alter the time:
1. Use the UP ARROW and DOWN ARROW keys to select the field you want to change (hour, minutes or seconds).
2. Use the LEFT ARROW and RIGHT ARROW keys to scroll through the field's possible values until you reach the correct one.

Once the correct time is set you should not need to set it again, except at the start and end of daylight saving time.

Diskette Drive
The computer supports up to two diskette/floppy-disk drives. Both have several possible settings:

None
360 Kbyte, 5.25 inch
1.2 Mbyte, 5.25 inch
720 Kbyte, 3.5 inch
1.44 Mbyte, 3.5 inch
2.88 Mbyte, 3.5 inch

Diskette drive A is always a 1.44 Mbyte, 3.5" drive.

Diskette drive B (if fitted) will usually be a 1.2 Mbyte, 5.25" floppy disk drive.

Hard Disks
The motherboards two ATA/IDE (AT Attachment Intergrated Drive Electronics) interfaces support a total of four drives (that is, two drives per interface). However, the computer itself can accommodate at most two IDE hard disk drives plus one ATA removable-media drive. The hard disk drives should be connected to the primary interface, and any removable-media drive connected to the secondary interface.

Configuring hard disk drives
It is important that you select the correct drive type for each hard disk drive. The BIOS Setup utility provides three methods of specifying drive type information:

The simplest method is to set Hard Disk 0 (or Hard Disk 1) to "Auto", meaning "auto-detect". The BIOS interrogates the drive and, if it is recognised, automatically sets the drive type information. Most drives can be interrogated in this way.

You can make a selection from one of the BIOS Setup's predefined drive types, numbered 1 to 99.
You can manually enter parameters by setting the drive type to "User" and pressing the ENTER key. Use the LEFT ARROW and RIGHT ARROW keys to move along the line of parameters, entering Cylinder, Head and Sector numbers as you go. When you have finished, press ESC.

If auto-configuration is not possible, drive type information can be obtained from your supplier, the drive manufacturer's documentation, or the label attached to the drive.
The Hard Disk 0 and Hard Disk 1 entries are greyed-out if you enable the AutoConfiguration Mode option. In this mode the BIOS always auto-configures the drive types.

Caution
If the drive is already formatted, selected the wrong drive type may result in loss of data. If the drive is not formatted, selecting the wrong drive type may mean that the drive's full capacity is not used. We recommend that the first time you turn on the computer you invoke BIOS Setup and make a note of the drive type parameters. This will ensure that you can always re configure the drive type correctly.

Configuring an ATA-PI CD-ROM drive
Assuming that the CD-ROM is connected to the secondary ATA/IDE interface, as recommended, set the Hard Disk 2 drive type to "CD".
If there is no ATA device fitted, the Hard Disk 2 drive type should be "None". Obviously, Hard Disk 3 drive type should always be "None".

System Memory
The BIOS automatically detects the total amount of system memory and shows this in the BIOS Setup utility. The three system memory parameters (Base, Extended and Total) are displayed for information only and are not user-adjustable. If you install additional memory, the BIOS updates the memory parameters accordingly.

Math Coprocessor
The BIOS automatically detects the presence of a coprocessor and shows this in the BIOS Setup utility.

Video Display
The BIOS automatically detects the video mode of your primary display and shows this in the BIOS Setup utility.

Basic System Configuration Page 2

Communication Settings
This option allows you to set the baud rate, parity, stop bit and data length for serial port 1.

The default values for the port are 9600 baud, odd parity, 1 stop bit and 7 bit data word.

Enhanced IDE Features
These options control a set of performance-enhancing features for hard disk drives. Most drives nowadays support these features, although some depend on what operating system you are using.

Hard Disk Block Mode
This option enhances performance for drives that support block mode. When enabled, it allows the computer to read and write more information at one time. (If the computer no longer boots after enabling this option, it is likely that the master hard disk does not support this function. Run BIOS Setup and disable the option.)

Hard Disk PIO Mode 3
This option enhances performance for drives that support polled input/output (PIO) modes. PIO mode 3 is the fastest mode. Disable this option if the master hard disk does not support this function.

Hard Disk Size > 504 MB
Enable this feature if the computer has a hard disk with a capacity greater than 504 megabytes and you are using the MS-DOS/Windows operating system. For hard disks of lesser capacity, or if you are using another operating system, this option should be disabled.

Hard Disk 32-Bit Access
This option enhances performance for drives that support it. However, the feature currently works only under the MS-DOS/Windows and NetWare operating systems. If your operating system or hard disk does not support 32-bit access, this option should be disabled.

Num Lock After Boot
If this option is enabled, the numeric keypad on the keyboard is automatically set to provide numeric keys rather than cursor control keys at the boot time. The default setting is disabled.

Memory Test
If this option is enabled, the POST (power-on self test) routines test the system memory at boot time.

If you enable the Fast Boot Mode option, Memory Test is disabled automatically, and the entry greyed-out so that you cannot re-enable it without first disabling Fast Boot Mode.

Auto Configuration Mode
If this option is enabled, certain BIOS Setup options are returned to their default settings and/or greyed-out so that they cannot be altered:

The Hard Disk 0 and Hard Disk 1 entries in the Basic System Configuration screen are set to "Auto" (meaning "auto-detect").

Shadow RAM (for system and video BIOS), Internal Cache and External Cache are all "Enabled", and System Speed is set to "High" in the Advanced System Configuration screen.

Auto Configuration Mode is enabled by default.

Fast Boot Mode
If this option is enabled, certain BIOS Setup options are set to ensure that the computer boots as quickly as possible and then greyed-out so that they cannot be altered until Fast Boot Mode is disabled again.

Memory Test is set to "Disabled" in the Basic System Configuration screen.
Shadow RAM (for system and video BIOS), Internal Cache and External Cache are all "Enabled", and System Speed is set to "High" in the Advanced System Configuration screen.

Fast Boot Mode is enabled by default.

Advanced System Configuration allows you to modify settings for shadow RAM, internal and external caches, system speed and so on.

Shadow RAM
This option allows you to shadow the computer's system and/or video BIOS read-only memory (ROM). You can also shadow individual 32 Kbyte (8000h) areas of expansion card ROM addressed between C8000h and EFFFFh.

To "shadow" ROM means to copy its contents into the computer's system or random-access memory (RAM). This is beneficial for two reasons: ROM has (relatively) long access times and the processor can access RAM faster than ROM; second, the contents of RAM can be cached for even greater performance.

Note that the two 32 Kbyte areas from E0000h to E7FFFh and E8000h to EFFFFh cannot be shadowed independently of the system BIOS ROM.

Internal Cache (CPU Cache)
This option enables or disables the internal memory cache (that is, the cache within the processor itself). There should normally be no reason to disable this cache, as this will result in poorer performance. Some old software which is speed sensitive may not work properly with the cache enabled, but this is very rare nowadays.

External Cache
This option enables or disables the external memory cache (if any). If an external cache is fitted, there should normally be no reason to disable it.

An external cache is an area of dedicated memory with significantly faster access times than the computer's system memory. A cache controller ensures that the cache always contains a copy of the most recently accessed areas of system memory, so that the processor is able to read it much more quickly.

An external cache is sometimes called a second-level cache, to distinguish it from the internal or first-level cache contained within the processor itself.

Cache Scheme
If the internal/external cache is enabled, and the processor allows, you can set the cache scheme to "Write Back" or "Write Through".

These are two alternative ways the cache controller can work. The write-back method updates the cache but not the system memory when there is a write instruction; it updates the memory only when there is an inconsistency between the cache and the memory. The write-through method updates both the cache and the memory whenever there is a write instruction.

The write-back method is quicker, but the write-through method is slightly safer (there is less chance of the contents of the cache getting out of step with the contents of system memory). For most everyday computing needs, you should set the Cache Scheme to "Write Back".

Some types of processor have a fixed cache scheme (usually write-through) that you can't change. In this case the Cache Scheme option is greyed-out.

System Speed
This option allows you to set the speed of the ISA (expansion card) bus.

System Memory Parity
This option enables or disables parity checking of random-access memory for those systems that support it (most systems do not).

Memory at 15MB-16MB
This option allows the memory address range from 15 Mbyte to 16 Mbyte (F00000h to FFFFFFh) to be reserved for use by system memory or an ISA expansion card.

Power Saving Configuration allows you to configure the power management features which make the computer Energy Star compliant.

Power Management Mode
Power Management Mode may be enabled or disabled. If enabled, the following options apply. Note that these options are not affected by the Load System Default Settings option of BIOS Setup.

Monitor Power-Saving Timer
This option is intended to be used only with monitors that support Display Power Management Signalling (DPMS).

You can specify an inactivity timeout between 1 and 15 minutes. If the display does not change in this time, the monitor enters a power-saving Suspend mode. The monitor returns to full power when you move the mouse or press any keyboard key.

IDE Hard Disk Standby Timer
This option is intended to be used only with hard disk drives that support ATA/IDE Power Mode commands.

You specify an inactivity timeout between 1 and 15 minutes. If there are no hard (fixed) disk read/writes during this time, the drive enters a power-saving Standby mode (the drive is spun down). The drive is spun up again when it is next accessed. Depending on the drive, it can take several seconds for the drive to spin up.

System Standby Timer
This option is a combination of the first two options, but extended to cover system activity.

You can specify a system inactivity timeout of up to 120 minutes. If there is no system activity during this time, the monitor enters Suspend mode and the hard disk drive(s) enter Standby mode. The monitor and hard disk drive(s) return to normal operation when you move the mouse or press any keyboard key.

System Suspend Timer
This option provided the maximum power savings.

You can specify a system inactivity timeout of up 120 minutes. If there is no system activity during this time:

The monitor enters the DPMS Off mode (that is, the monitor is effectively turned off).
The hard disk drive(s) enter Standby mode (they are spun down).
Several motherboard components are put into a power-saving mode.
The processors' internal clock is stopped.

The system returns to normal operation when you move the mouse or press any keyboard key.

Power Saving Configuration page 2

Monitored Activities
You can use these options to enable or disable system activity monitoring and so specify what you mean by "system inactivity" in relation to the System Standby and System Suspend modes. You can tell the BIOS to monitor selected interrupt requests (IRQs) and direct memory access requests (DRQs). Activity on any one of the enabled IRQs or DRQs resets the system inactivity timer and keeps the system out of the power-saving modes.

System Security allows you to configure the motherboard security features. These include setting passwords, restricting access to diskette and hard disk drives, and configuring the serial and parallel ports.

Disk Drive Control
These options allow you to control access to diskette/floppy disk drives and hard disk drives, and to specify where the BIOS should look for an operating system when the computer boots. Use these options to reduce the risk of computer viruses being introduced into the computer.

Diskette Drive and Hard Disk Drive
Both these options have the same four possible settings:

Note that write-protection inhibit write accesses through the BIOS, therefore these options work only for operating systems which use the BIOS to access the drives (for example, MS-DOS).

System boot drive
This option specifies where the BIOS looks for an operating system.

Note that if the BIOS finds a non-system diskette in drive A, you will be prompted to replace it.

On-Board Communication Ports

Serial Port Base Addresses
These options allow each of the two serial ports to be disabled, or to configured as COM1, COM2, COM3 or COM4.

The two serial ports must be set to different COM ports. Attempting to configure both serial ports to the same COM port will result in one port being disabled.

Parallel Port Base Address
This option allows the parallel port to be disabled, or to configured with the I/O port base addresses shown below.

If you install an expansion card with a port that uses the same I/O port address as the parallel port, the parallel port is disabled automatically.

Parallel Port Operation Mode
This option allows you to set the mode of the parallel port:

Passwords
These password options are intended for computers that lack more sophisticated security systems. You should not attempt to use these options on an Apricot XEN-PC LS computer with a built-in LOC Technology security system.

Some caution is required when using these options. At the factory, a jumper on the motherboard is set to "Bypass" password checking. With the jumper in this position, you can define passwords, but the computer will not prompt for them. To enable password checking you must move the jumper to the "Check" position.

Password Setting

Setup Password
This option allows you to set a password for the BIOS Setup utility. When this option is in operation only people who know the password can run the BIOS Setup utility and re configure the system. A small "key" icon appears in the top left hand corner of the screen. The person wanting to run BIOS Setup must then type the password and press ENTER. Three attempts are permitted, after which the computer is disabled and must be turned off then on again.

Power-On Password
This option allows you to set a password that is requested every time the computer is turned on or rebooted. Only people who know the password can use the computer. A small "key" icon appears in the top left-hand corner of the screen. The person wanting to use the computer must then type the password and press ENTER. Three attempts are permitted, after which the computer is disabled and must be turned off then on again.

Load Setup Default Settings resets all settings (except power management and security) back to their default settings. The default settings are the ones shown on the example screens shown. You can use this option if the battery sustaining CMOS memory loses power, or if the memory itself becomes corrupted.