The VS440FX motherboard may contain design defects or errors known as errata. Characterized errata that
may cause the VS440FX motherboard’s behavior to deviate from published specifications are documented in
the VS440FX Motherboard Specification Update.
Revision History
Revision
-001
-002
-003
Revision HistoryDate
Preliminary release of the VS440FX Technical Product Specification.4/96
Second release of the VS440FX Technical Product Specification.5/96
Updated to reflect Fab E10/96
This product specification applies only to standard VS440FX motherboards with BIOS
identifier CS1.
Changes to this specification will be published in the VS440FX Motherboard Specification
Update before being incorporated into a revision of this document.
Information in this document is provided in connection with Intel products. No license, express or implied, by estoppel or
otherwise, to any intellectual property rights is granted by this document. Except as provided in Intel’s Terms and Conditions of
Sale for such products, Intel assumes no liability whatsoever, and Intel disclaims any express or implied warranty, relating to
sale and/or use of Intel products including liability or warranties relating to fitness for a particular purpose, merchantability, or
infringement of any patent, copyright or other intellectual property right. Intel products are not intended for use in medical, life
saving, or life sustaining applications.
Intel retains the right to make changes to specifications and product descriptions at any time, without notice.
The VS440FX motherboard may contain design defects or errors known as errata. Current characterized errata are available
on request.
Contact your local Intel sales office or your distributor to obtain the latest specifications before placing your product order.
†
Third-party brands and names are the property of their respective owners.
Copies of documents which have an ordering number and are referenced in this document, or other Intel literature, may be
obtained from:
Intel Corporation
P.O. Box 7641
Mt. Prospect, IL 60056-7641
or call in North America 1-800-879-4683, Europe 44-0-1793-431-155, France 44-0-1793-421-777,
Germany 44-0-1793-421-333, other Countries 708-296-9333.
The VS440FX motherboard supports Pentium® Pro microprocessors operating at 150, 166, 180,
and 200 MHz. The Pentium Pro microprocessor includes 16 KB of L1 cache on the chip. A
256 KB or 512 KB L2 cache device is contained in the same package as the microprocessor. The
motherboard features:
• ATX form factor
• Socket 8 Pentium Pro processor socket
Main Memory
†
• Four 72-pin SIMM
• Support for up to 256 MB of Extended Data Out (EDO) or fast page memory
• Support for non-parity, parity, or Error Checking and Correcting (ECC) DRAM
Chipset and PCI/IDE Interface
• Intel 82440FX PCIset
• Integrated PCI bus mastering controller
• Two fast IDE interfaces
• Support for up to four IDE drives or devices
• Support for two Universal Serial Bus (USB) interfaces
sockets
I/O Features
• PC87308/87307 Super I/O controller
• Integrates standard I/O functions: floppy drive interface, one multi-mode parallel port, two
FIFO serial ports, real-time clock, keyboard and mouse controller, and IrDA
interface
A. Optional Crystal Audio deviceP. Floppy connector
B. Optional CD-ROM audio connectorQ. IDE connectors
C. Optional wavetable connectorR. Front panel connectors
D. Optional telephony connectorS. Onboard speaker
E. VCCP voltage regulatorT. Intel 82371SB PIIX3
F. MIDI/game port/audio jacksU. Battery
G. Parallel port/serial connectorsV. Jumper block
H. Optional USB connectorsW. National PC87308/87307 Super I/O controller
I. Keyboard and mouse connectorsX. Auxiliary fan connector
J. Pentium Pro microprocessor / Socket 8Y. Flash BIOS
K. Power connectorZ. Management Extension Hardware ASIC
L. Intel 82441FXAA. ISA add-in board connectors
M. Microprocessor fan connectorBB. SIMM connectors
N. Intel 82442FXCC. PCI add-in board connectors
O. VTT voltage regulator
The motherboard is designed to fit into a standard ATX form factor chassis. Figure 2 illustrates the
mechanical form factor for the motherboard. Location of the I/O connectors and mounting holes is
in strict compliance with the ATX specification (refer to Section 5.1).
Note: Material = 0.010 ±.0.001 Thick Stainless Steel, Half Hard
0.671
1.955
0.597
0.553
1.911
2.184
3.327
4.735
4.899
5.391
5.883
6.533
0.193
0.768
0.295
0.458
1.158
0.666
4.610
1.590
0.200
1.407
0.652
0.133
0.120
2.055
2.326
2.023
0.050
1.4 I/O Shield
The back panel I/O shield for the VS440FX motherboard must meet specific dimensional and
material requirements. Computers based on this motherboard need the back panel I/O shield in
order to pass certification testing. Figure 3 shows the critical dimensions for both options of the
I/O shield and indicates the position of each cutout.
Figure 3. Back Panel I/O Shield (with Audio option) Dimensions
10
Motherboard Description
1.5 Microprocessor
The motherboard operates with 2.1 V to 3.5 V Pentium Pro processors. The onboard voltage
regulator is automatically programmed and controlled by the VID pins of the processor to provide
the required voltage. The motherboard supports Pentium Pro processors that run internally from
150 MHz up to 200 MHz.
The motherboard supports Pentium Pro processors with either 256 KB or 512 KB of second-level
cache.
The processor maintains full backward compatibility with the 8086, 80286, Intel386
and Pentium processors. Its numeric coprocessor maintains backward compatibility with math
coprocessors and that comply with ANSI/IEEE standard 754-1985.
1.5.1 Microprocessor Heatsink and Clips
CAUTION
Do not use the older style of bail-wire clips for securing the heat sink assembly. These clips have
been known to damage the motherboard when installed or removed incorrectly.
TM
, Intel486TM,
An approved Pentium Pro processor heat sink is necessary for proper thermal dissipation. The
processor/heat sink assembly must be securely fastened to the ZIF socket by two clips. These clips
fit over the heat sink assembly and attach to tabs on the socket.
1.5.2 Microprocessor Upgrade
The motherboard has a Socket 8 processor socket. Socket 8 is a 387-pin modified staggered pin
grid array (SPGA) ZIF socket with a voltage regulator for the processor core. The socket supports
upgrades to future Pentium Pro OverDrive
The motherboard has four SIMM sockets arranged in two banks: Bank 0 and Bank 1. Each bank
has two sockets. SIMMs in the same bank must be the same type, size, and speed; SIMMs in
different banks may differ in type, size, and speed. SIMMs must be installed in both sockets of a
bank, and at least one bank must be filled. The BIOS automatically detects memory type and size
so no jumper settings are required.
The motherboard supports:
• 72-pin SIMMs with tin-plated contacts
• 60 ns fast page mode SIMMs or 60 ns EDO SIMMs
• Non-parity, parity, or ECC SIMMs
• Single- or double-sided SIMMs in the following sizes:
Configuration
SIMM size
4 MB1 x 321 x 36
8 MB2 x 322 x 36
16 MB4 x 324 x 36
32 MB8 x 328 x 36
64 MB16 x 3216 x 36
(non-parity)
Configuration
(parity)
1.6.1 EDO DRAM
EDO DRAM improves memory read performance by holding the memory data valid until the next
CAS# falling edge, unlike fast page mode DRAM, which tri-states the memory data when CAS#
negates to precharge for the next memory cycle. With EDO DRAM, the CAS# precharge overlaps
the data-valid time, which allows CAS# to negate earlier while still satisfying the memory-data
valid window.
1.6.2 Parity/ECC DRAM
Memory error checking and correction is supported by parity memory. With parity memory, the
motherboard can be configured to support ECC memory operation. Parity SIMMs are
automatically detected, but you must enter Setup to configure the memory for either Parity or ECC
operation. Parity memory detects single-bit errors. ECC memory detects double-bit errors and
corrects single-bit errors.
12
Motherboard Description
1.7 Chipset
The Intel 82440FX PCIset consists of the 82441FX PCI Bridge and Memory Controller (PMC),
the 82442FX Data Bus Accelerator (DBX), and one 82371SB PCI/ISA IDE Xcelerator (PIIX3)
bridge chip.
1.7.1 82441FX PCI Bridge and Memory Controller (PMC)
The PMC provides all control signals necessary to drive second level cache and main memory,
including multiplexed address signals. It also controls system access to memory and generates
snoop controls to maintain cache coherency. The PMC comes in a 208-pin QFP package that
features:
• Integrated DRAM controller
64/72-bit non-interleaved path to memory
EDO and fast page DRAM support
Non-parity, parity, and ECC support
• Fully synchronous PCI bus interface
30 and 33 MHz bus speeds
PCI to DRAM data throughput at greater than 100 MB per second
Up to four PCI masters in addition to the PIIX3 and IDE
• Data Buffering
Pentium Pro processor-to-DRAM and PCI-to-DRAM write data buffering
Pentium Pro-processor-to-PCI burst writes
1.7.2 82442FX Data Bus Accelerator (DBX)
The DBX connects to the 64-bit Pentium Pro data bus, the 64/72-bit memory data bus, and the
16 bit PMC private data bus. The DBX works in parallel with the PMC to provide a high
performance memory subsystem for Pentium Pro processor based systems. The DBX comes in a
208-pin QFP package.
1.7.3 82371SB PCI/ISA IDE Xcelerator (PIIX3)
The PIIX3 is the interface between the PCI and ISA buses. It features an integrated dual-channel
enhanced IDE interface that supports up to four IDE devices. The PIIX3 comes in a 208-pin QFP
package that features:
• Integrated dual-channel enhanced IDE interface
Support for up to four IDE devices
PIO Mode 4 transfers at up to 16 MB per second
Integrated 8 x 32-bit buffer for bus master PCI IDE burst transfers
Bus master mode
• PCI compliance (refer to Section 5.1)
• Enhanced DMA controller supporting up to seven DMA channels
• Interrupt controller with PCI-to-ISA interrupt mapping circuitry
• A 16-bit counter/timer
• SMI interrupt logic and timer with fast on/off mode
• NMI circuitry
1.7.4 Universal Serial Bus Support
The motherboard features two optional USB ports. The ports permit the direct connection of two
USB peripherals without an external hub. If more devices are required, an external hub can be
connected to either of the built-in ports. The motherboard fully supports the standard universal
host controller interface (UHCI) and uses standard software drivers that are UHCI-compatible.
Features of the USB include:
• Self-identifying, hot pluggable peripherals.
• Automatic mapping of function to driver and configuration.
• Support for isochronous and asynchronous transfer types over the same set of wires.
• Support for up to 127 physical devices.
• Support for full speed (12 Mbs) and low speed (1.5 Mbs) USB connections. Full speed
connections require shielded cabling.
• Guaranteed bandwidth and low latencies appropriate for telephony, audio, and other
applications.
• Error handling and fault recovery mechanisms built into protocol.
1.7.5 IDE Support
The motherboard has two independent bus mastering PCI IDE interfaces that support PIO Mode 3,
PIO Mode 4, and ATAPI (e.g., CD-ROM) devices. The BIOS supports Logical Block Addressing
(LBA) and Extended Cylinder Head Sector (ECHS) translation modes. IDE device transfer rate
and translation mode are automatically detected by the BIOS.
Normally, programmed I/O operations require a substantial amount of processor bandwidth;
however, in true multi-tasking operating systems such as Windows
mastering IDE can be devoted to other tasks while disk transfers are occurring.
14
†
95, the bandwidth freed by bus
Motherboard Description
1.8 Super I/O Controller
The PC87308/87307 Super I/O Controller from National Semiconductor is a fully Plug and Play
compatible device which provides:
• Serial ports: two NS16C550-compatible UARTs with send/receive 16-byte FIFO
• Multimode bidirectional parallel port
†
Standard mode, IBM
Enhanced Parallel Port (EPP) mode with BIOS and driver support
High-speed Extended Capabilities Port (ECP) mode
• Industry standard floppy controller with 16-byte FIFO and 2.88 MB floppy drive support
• 8042-compatible keyboard controller
• Real-time clock accurate within ±13 minutes a year at 25 ºC and 5 V
• Support for an IrDA-compliant infrared interface
By default, the I/O controller interfaces are automatically configured during boot up. The I/O
controller can also be manually configured in the Setup program.
1.8.1 Serial Ports
and Centronics† compatible
The motherboard has two 9-pin D-Sub serial port connectors located on the back panel. The
NS16C550-compatible UARTs support data transfers at speeds up to 921.6 kBaud (standard) or
1.5 MBaud.
1.8.2 Parallel Port
The connector for the multimode bidirectional parallel port is a 25-pin D-Sub connector located on
the back panel of the motherboard. In the Setup program, there are four options for parallel port
operation:
• Compatible (standard mode).
†
• Bidirectional (PS/2
• Bidirectional EPP. A driver from the peripheral manufacturer is required for operation.
• Bidirectional high-speed ECP.
compatible).
1.8.3 Floppy Controller
The I/O controller is software compatible with the DP8473 and 82077 floppy drive controllers. In
the Setup program, the floppy interface can be configured for the following floppy drive capacities
and sizes:
PS/2 keyboard and mouse connectors are located on the back panel of the motherboard. The 5 volt
lines to these connectors are protected with a PolySwitch
reestablishes the connection after an over-current condition is removed. While this device
eliminates the possibility of having to replace a fuse, power to the computer should be turned off
before connecting or disconnecting a keyboard or mouse.
NOTE
✏
You can plug the mouse and keyboard into either connector.
The keyboard controller contains the AMI Megakey keyboard and mouse controller code, which
provides the traditional keyboard and mouse control functions, and also supports Power On/Reset
password protection. A Power On/Reset password can be specified in the Setup program.
The keyboard controller also supports the following hot-key sequences:
• <CTRL><ALT><DEL> Software reset. This key sequence resets the computer’s software by
jumping to the beginning of the BIOS code and running the Power On Self Test (POST).
• <CTRL><ALT><+> and <CTRL><ALT><-> Turbo mode. Note that Turbo mode could be
affected by the operating system, or whether the processor is in protected mode or virtual
x86 mode.
<CTRL><ALT><-> For Deturbo mode (emulates a 23 MHz AT)
<CTRL><ALT><+> For Turbo mode
• <CTRL><ALT><defined in Setup> Power management. This key sequence invokes power
managed mode, which reduces the computer’s power consumption while maintaining its ability
to service external interrupts.
• <CTRL><ALT><defined in Setup> Keyboard lock. This key sequence is a security feature
that locks the keyboard until the User password is entered. When keyboard lock is invoked,
the keyboard LEDs flash. To enable the keyboard lock feature, a User password must be
specified in the Setup program.
†
circuit that, like a self-healing fuse,
1.8.5 Real-Time Clock, CMOS RAM, and Battery
The real-time clock is compatible with DS1287 and MC146818 components. It provides a timeof-day clock and a 100-year calendar with alarm features and century rollover. The real-time clock
also supports 242-bytes of battery-backed CMOS RAM in two banks, which are reserved for
BIOS use.
The time, date, and CMOS values can be specified in the Setup program. The CMOS values can
be returned to their defaults by using the Setup program or by setting a configuration jumper on the
motherboard.
An external coin-cell battery powers the real-time clock and CMOS memory. If the computer is
not plugged into a wall socket, the battery has an estimated life of three years. When the computer
is plugged in, the 5 volt standby current from the motherboard’s power supply extends the life of
the battery. The RTC is accurate to ±13 minutes/year at 25 ºC and 5 V conditions.
16
Motherboard Description
1.8.6 Infrared Support
The motherboard has a 5-pin header that supports Hewlett Packard† HSDSL-1000 compatible
infrared (IR) transmitters/receivers. The connection can be used to transfer files to or from portable
devices like laptops, PDAs, and printers. The Infrared Data Association (IrDA) specification
supports data transfers of 115 Kbps at a distance of 1 meter.
1.8.6.1 Consumer Infrared Support
The motherboard has a signal pin that supports Consumer IR devices (remote controls). The signal
pin supports receive only. Consumer IR devices can be used to control telephony functions and
multimedia operations like volume and CD track changes. A software and hardware interface is
needed to use this feature.
1.9 Audio Subsystem
The optional onboard audio subsystem features the Crystal CS4236, a 100-pin TQFP audio codec
with an integrated FM synthesizer. The audio subsystem provides all the digital audio and analog
mixing functions needed for recording and playing sound on personal computers. Together, these
components feature:
• Stereo analog-to-digital and digital-to-analog converters
• Analog mixing, anti-aliasing, and reconstruction filters
• Line and microphone level inputs
• ADPCM, A-law, or µlaw digital audio compression/decompression
• Full digital control of all mixer and volume control functions
• Full duplex operation
• Sound Blaster† game and Windows Sound System compatibility
The audio subsystem requires up to two DMA channels and two IRQs. The following table shows
the IRQ, DMA channel, and base I/O address options.
Resource
Sound Blaster
(DMA playback, DMA / IRQ shared
with Windows Sound System capture)
Windows Sound System
(DMA playback)
MPU-401
(IRQ shared with Sound Blaster)
MIDI / Game Port
FM Synthesis
CS4236 Control
IRQ
(Options)
5 (best choice)
7
9
11
5
7
9 (best choice)
11
5 (best choice)
7
9
11
DMA channel
(Options)
0 (best choice)
3
0
1 (best choice)
3
1.9.1 Audio Drivers and Utilities
Audio software and utilities are available from Intel’s World Wide Web site (refer to Section 5.2).
1.9.2 CD-ROM Audio Connector
A 1 x 4-pin connector is available for connecting an internal CD-ROM reader to the audio
subsystem’s mixer. The connector is compatible with most cables supplied with ATAPI CD-ROM
readers designed to connect to audio add-in cards.
1.9.3 Telephony Connector
A 2 x 2-pin connector is available for connecting the monaural audio signals of an internal
telephony device such as a fax/modem to the motherboard’s audio subsection. The mono-in and
mono-out signal interface is necessary for telephony applications such as speakerphones and
answering machines.
1.9.4 Wavetable Connector
An 8-pin connector supports wavetable add-in cards. Most wavetable add-in cards are installed in
a standard ISA slot; a cable is then routed from the card to the connector.
Compatible wavetable cards are available from several vendors. The ICS WaveFront and the
CrystaLake Series 2000 wavetable product families offer general MIDI-compatible audio
operation.
18
Motherboard Description
1.10 Management Extension Hardware
The optional Management Extension hardware provides low-cost instrumentation capabilities
designed to reduce the total cost of owning a PC. The hardware implementation is a single-chip
ASIC. Features include:
• An integrated temperature sensor
• Fan speed sensors for up to three fans
• Power supply voltage monitoring to detect levels above or below acceptable values
• Registers for storing POST hardware test results and error codes
• Security switch for detecting physical intrusion, such as when the chassis lid has been removed
(even when power is off). A photosensor is used as the switch.
• Remote reset capabilities from a remote peer or server through LANDesk
Version 3.0 and service layers (when available)
• Hardware compatibility with Windows NT
†
When suggested ratings for temperature, fan speed, or voltage are exceeded, an interrupt is
activated.
The Management Extension circuitry connects to the ISA bus as an 8-bit I/O mapped device. It
uses these I/O addresses:
Client Manager,
Address (hex)*Description
80POST codes
85Address and control functions of the ASIC
86Register read/write operations for the ASIC
*These addresses are accessible only when the processor is in System