Intel AN430TX - Motherboard - ATX Configuration guide

AN430TX Motherboard
Technical Product Specification
The AN430TX motherboard may contain design defects or errors known as errata which may cause the product to deviate from published specifications. Current characterized
errata are documented in the AN430TX Motherboard Specification Update.
April, 1997
Order Number 282955-001

Revision History
Revision
Revision History Date
-001
First release of the AN430TX Motherboard Technical Product Specification. 4/97
This product specification applies only to standard AN430TX motherboards with BIOS
identifier AN430TX0.86A.
Changes to this specification will be published in the AN430TX 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 AN430TX may contain design defects or errors known as errata which may cause the product to deviate from published
specifications. 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.
Copyright 1997, Intel Corporation. All rights reserved.

iii
Contents
1 Motherboard Description
1.1 Overview......................................................................................................................7
1.2 Motherboard Manufacturing Options............................................................................9
1.3 Form Factor ...............................................................................................................10
1.4 I/O Shield...................................................................................................................11
1.5 Microprocessor...........................................................................................................12
1.5.1 Microprocessor Upgrade..............................................................................12
1.6 Memory......................................................................................................................13
1.6.1 Main Memory...............................................................................................13
1.6.2 Second Level Cache ...................................................................................14
1.7 Chipset.......................................................................................................................14
1.7.1 82439TX System Controller (MTXC) ...........................................................14
1.7.2 82371AB PCI ISA IDE Xcelerator (PIIX4) ....................................................15
1.7.3 Universal Serial Bus (USB) Support ............................................................16
1.7.4 IDE Support.................................................................................................16
1.8 Super I/O Controller ...................................................................................................17
1.8.1 Serial Ports..................................................................................................17
1.8.2 Parallel Port.................................................................................................18
1.8.3 Floppy Controller .........................................................................................18
1.8.4 Keyboard and Mouse Interface....................................................................18
1.8.5 Infrared Support...........................................................................................19
1.9 Graphics Subsystem..................................................................................................19
1.9.1 Graphics Controller......................................................................................19
1.9.2 VESA/ATI Multimedia Channel Connector ..................................................20
1.9.3 Brooktree Video Capture Processor ............................................................20
1.9.4 ImpacTV NTSC/PAL Encoder......................................................................21
1.10 Audio Subsystem.......................................................................................................22
1.10.1 Yamaha OPL4-ML.......................................................................................23
1.10.2 Audio Drivers and Utilities............................................................................23
1.10.3 Audio Connectors........................................................................................23
1.10.4 CD-ROM audio connector............................................................................23
1.11 Motherboard Connectors ...........................................................................................24
1.11.1 Power Supply Connector .............................................................................29
1.11.2 Front panel Connectors ...............................................................................30
1.11.3 Back Panel Connectors ...............................................................................33
1.11.4 Optional TV/Video Riser Card Connectors ..................................................36
1.12 Add-in Board Expansion Connectors .........................................................................38
1.13 Jumper Settings.........................................................................................................41
1.13.1 Processor Configuration (J9C1-C, D) ..........................................................42
1.13.2 Password Clear (J9C1-A) ............................................................................43
1.13.3 Clear CMOS (J9C1-A).................................................................................43
1.13.4 BIOS Setup Access (J9C1-B)......................................................................43
1.13.5 BIOS Recovery (J8A1) ................................................................................43
1.13.6 Processor Voltage (J6M1) ...........................................................................43

AN430TX Motherboard Technical Product Specification
iv
1.14 Reliability....................................................................................................................43
1.15 Environmental............................................................................................................44
1.16 Power Consumption...................................................................................................44
1.16.1 Power Supply Considerations......................................................................45
1.17 Regulatory Compliance..............................................................................................45
1.17.1 Safety ..........................................................................................................45
1.17.2 EMI..............................................................................................................46
1.17.3 Product Certification Markings.....................................................................46
2 Motherboard Resources
2.1 Memory Map..............................................................................................................47
2.2 DMA Channels...........................................................................................................47
2.3 I/O Map......................................................................................................................48
2.4 PCI Configuration Space Map....................................................................................50
2.5 Interrupts....................................................................................................................50
2.6 PCI Interrupt Routing Map .........................................................................................51
3 BIOS and Setup Program
3.1 Introduction................................................................................................................53
3.1.1 BIOS Flash Memory Organization ...............................................................53
3.1.2 BIOS Upgrades ...........................................................................................54
3.1.3 Plug and Play: PCI Auto-configuration ........................................................54
3.1.4 PCI IDE Support ..........................................................................................54
3.1.5 ISA Plug and Play........................................................................................55
3.1.6 ISA Legacy Devices.....................................................................................55
3.1.7 Desktop Management Interface...................................................................55
3.1.8 Advanced Power Management....................................................................56
3.1.9 Language Support .......................................................................................56
3.1.10 Boot Options................................................................................................57
3.1.11 OEM Logo or Scan Area..............................................................................57
3.1.12 USB Support................................................................................................57
3.1.13 BIOS Setup Access Jumper ........................................................................57
3.1.14 Recovering BIOS Data ................................................................................58
3.2 BIOS Setup Program .................................................................................................58
3.2.1 Overview of the Setup Menu Screens .........................................................58
3.2.2 Main Menu...................................................................................................59
3.2.3 Primary/Secondary IDE Master/Slave Configuration Submenus .................61
3.2.4 Advanced Menu...........................................................................................63
3.2.5 Security Menu..............................................................................................67
3.2.6 Power Menu ................................................................................................68
3.2.7 Boot Menu ...................................................................................................68
3.2.8 Exit Menu.....................................................................................................70
4 Error Messages
4.1 BIOS Error Messages ................................................................................................71
4.2 Port 80h POST Codes ...............................................................................................72

Contents
v
5 Specifications and Online Support
5.1 Specifications.............................................................................................................79
5.2 Online Support...........................................................................................................80
Figures
1. Motherboard Components ...........................................................................................8
2. Motherboard Dimensions...........................................................................................10
3. Back Panel I/O Shield Dimensions ............................................................................11
4. Motherboard Connectors ...........................................................................................24
5. Front Panel I/O Connectors .......................................................................................30
6. Back Panel I/O Connectors........................................................................................33
7. TV/Video Riser Card Connectors...............................................................................36
8. Jumper Locations.......................................................................................................41
Tables
1. ATI-264GT Rage II+ Maximum Refresh Rates at Different Resolutions ....................20
2. Standard CD-ROM Audio Connector (J2G2) .............................................................25
3. Optional ATAPI Audio Connector (J2G1)...................................................................25
4. Line-In Audio Input Connector (J2H3)........................................................................25
5. Telephony Connector (J2H4) .....................................................................................25
6. Serial Port 2 Header (J2J1)........................................................................................25
7. CPU Fan Connector (J6M2).......................................................................................26
8. Floppy Drive Connector (J7L2) ..................................................................................26
9. Optional Video Capture Input Connector (J7B1) ........................................................26
10. GPIO Header (J9A1)..................................................................................................27
11. PCI IDE Connectors (J9H1, J10H1)...........................................................................27
12. System Fan Connector (J10A1).................................................................................27
13. Optional VESA/ATI Multimedia Channel Connector (J5F1) .......................................28
14. Optional Video Riser Header (J3F1) ..........................................................................28
15. Power Supply Connector (J7L1) ................................................................................29
16. Front Panel I/O Connectors .......................................................................................31
17. PS/2 Keyboard and Mouse Connectors .....................................................................34
18. USB Connectors ........................................................................................................34
19. Parallel Port Connector..............................................................................................34
20. Serial Port Connector.................................................................................................34
21. Optional VGA Video Monitor Connector ....................................................................35
22. MIDI / Game Port Connector......................................................................................35
23. S-Video Out Connector..............................................................................................36
24. RCA Composite Video Out Connector .......................................................................36
25. S-Video In and I2C Connector...................................................................................37
26. RCA Composite Video In Connector..........................................................................37
27. PCI Bus Connectors ..................................................................................................38
28. ISA Bus Connectors...................................................................................................39
29. Jumper Settings.........................................................................................................42
30. Jumper Settings for Processor and Bus Frequencies ................................................42
31. Motherboard Environmental Specifications ................................................................44
32. DC Voltage.................................................................................................................44
33. Power Usage for a static Windows 95 Desktop .........................................................44
34. Memory Map..............................................................................................................47

AN430TX Motherboard Technical Product Specification
vi
35. DMA Channels...........................................................................................................47
36. I/O Map......................................................................................................................48
37. PCI Configuration Space Map....................................................................................50
38. Interrupts....................................................................................................................50
39. PCI Interrupt Routing Map .........................................................................................51
40. Flash Memory Organization.......................................................................................53
41. Recommendations for Configuring an ATAPI Device.................................................55
42. Overview of the Setup Menu Screens........................................................................59
43. BIOS Error Messages ................................................................................................71
44. Port 80h Codes..........................................................................................................73
45. Compliance with Specifications..................................................................................79

7
1 Motherboard Description
1.1 Overview
The AN430TX motherboard supports Pentiumprocessors and Pentium processors with MMX
technology. The motherboard features:
• ATX form factor
• Socket 7 Pentium OverDriveprocessor socket
Main Memory
• Two 168-pin DIMM sockets
• Support for up to 256 MB of:
 extended data out (EDO) memory
 unbuffered 4-clock synchronous DRAM (SDRAM) memory
• Up to 64 MB of main memory cacheable
Second Level Cache Memory
• 512 KB pipeline burst static RAM (PBSRAM) soldered to the motherboard
Chipset and PCI/IDE Interface
• Intel 82430TX PCIset
• Integrated PCI bus mastering controller
• Two fast IDE interfaces
• Support for up to four IDE drives or devices
• Support for Ultra DMA/33 drives
• Support for LS-120 removable media IDE drives
I/O Features
• PC87307VUL I/O controller
• Integrates standard I/O functions: floppy drive interface, one multimode parallel port, two
FIFO serial ports, keyboard and mouse controller, IrDA†-compatible interface
• Support for two Universal Serial Bus (USB) interfaces
Expansion Slots
• Standard version (without video option):
 Three PCI
 Two ISA
 One shared PCI/ISA
• With optional video subsystem:
 Three PCI
 Three ISA
 Video riser (required for TV-out and/or video capture)

AN430TX Motherboard Technical Product Specification
8
Audio Subsystem
• Yamaha OPL3-SA3 3-D audio codec soldered to the motherboard
• Yamaha OPL4-ML wavetable synthesizer soldered to the motherboard
Video Subsystem
• Optional ATI†-264GT Rage II+ 3-D graphics controller
• Optional Brooktree Bt829A video capture processor
• Optional ATI-ImpacTV†NTSC/PAL TV-out encoder
• Optional VESA†/ATI Multimedia Channel connector
Other features
• Plug and Play compatible
• Support for Advanced Power Management
Software drivers and utilities are available from Intel.
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Figure 1. Motherboard Components

Motherboard Description
9
A. Yamaha OPL3-SA3 audio codec S. Battery
B. Yamaha OPL4-ML component T. Optional ATI-264GT Rage II+ graphics controller
C. CD-ROM audio connector U. Optional Brooktree Bt829A video capture processor
D. Line-in audio input connector V. Front panel header
E. Telephony connector W. Onboard speaker
F. Back panel I/O connectors X. GPIO header
G. Serial port 2 header Y. System fan connector
H. 512 KB PBSRAM cache Z. Configuration jumper block
I. Socket 7 Pentium processor socket AA. Optional 2 MB of SGRAM video memory
J. 82430TX MTXC system controller BB. BIOS recovery jumper
K. Linear voltage regulator CC. 2 Mbit TSOP Flash memory device
L. Processor voltage jumper DD. Optional Video capture input connector
M. Fan connector EE. Optional ATI-ImpacTV NTSC/PAL TV-out device
N. Power connector FF. Optional VESA/ATI Multimedia Channel connector
O. Floppy drive connector GG. PCI connectors
P. 82430TX PIIX4 PCI ISA IDE Xcelerator HH. DIMM sockets
Q. PC87307VUL I/O controller II. Optional video riser card header
R. IDE connectors JJ. ISA connectors
1.2 Motherboard Manufacturing Options
• ATI-264GT Rage II+ 3-D graphics controller with 2 MB of SGRAM
• Brooktree Bt829A video capture processor
• ATI-ImpacTV NTSC/PAL TV-out encoder
• VESA/ATI Multimedia Channel connector
• Unshrouded floppy disk and IDE controller connectors

AN430TX Motherboard Technical Product Specification
10
1.3 Form Factor
The motherboard is designed to fit into a standard ATX form factor chassis. Figure 2 illustrates the
form factor for the motherboard. The location of the I/O connectors and mounting holes are in
strict compliance with the ATX specification (see Section 5.1).
OM06161
8.05
11.35
11.10
4.90
3.10
0.0
0.65
0.25 0.0
2.85
8.95
9.04
Figure 2. Motherboard Dimensions

Motherboard Description
11
1.4 I/O Shield
The back panel I/O shield for the AN430TX 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 the I/O shield and
indicates the position of each cutout. The example shown is chassis-specific and will not
necessarily work with other chassis types.
Left-end View
OM05669
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
0.133
0.120
2.055
2.326
2.023
0.050
0.652
0.395
0.990
0.306 Dia (3)
0.478
Figure 3. Back Panel I/O Shield Dimensions

AN430TX Motherboard Technical Product Specification
12
1.5 Microprocessor
The motherboard supports:
• Pentium processors operating at 90, 100, 120, 133, 150, 166, and 200 MHz
• Pentium processors with MMX technology operating at 166, and 200 MHz
An onboard voltage regulator derives the necessary voltage from the computer’s power supply and
enables use of standard or VRE-specified processors. The motherboard automatically detects the
type of processor (Pentium processor or Pentium processor with MMX technology).
CAUTION
If you use clips to secure a heat sink
to the processor, do not use bail-wire
style heat sink clips, such as the type
shown in the figure to the right.
These clips have been known to
damage the motherboard when
installed or removed incorrectly.
OM05908
1.5.1 Microprocessor Upgrade
The motherboard has a 321-pin Socket 7 zero insertion force (ZIF) microprocessor socket.
Socket 7 supports upgrades to higher performance Pentium OverDrive processors not supported by
Socket 5.

Motherboard Description
13
1.6 Memory
1.6.1 Main Memory
The motherboard has two 168-pin DIMM sockets. Memory can be installed in one or two sockets.
Minimum memory size is 8 MB. Maximum memory size is 256 MB. The BIOS automatically
detects memory type, size, and speed so no jumper settings are required.
The motherboard supports the following:
• 168-pin 3.3 V DIMMs with tin-plated contacts
• 60 and 66 MHz bus speeds
• 60 ns 3.3V EDO DRAM
• 60 ns unrestricted CAS Latency 2 unbuffered 4-clock 3.3V SDRAM
• Caching for the first 64 MB of main memory
• 64-bit data path
• Single- or double-sided DIMMs in the following sizes:
DIMM Size Type Configuration Technology
8 MB 60 ns EDO 1M x 64 16 Mbit
16 MB 60 ns EDO 2M x 64 16 Mbit
32 MB 60 ns EDO 4M x 64 16 Mbit
64 MB 60 ns EDO 8M x 64 16 Mbit
8 MB CAS Latency 2 SDRAM 1M x 64 16 Mbit
16 MB CAS Latency 2 SDRAM 2M x 64 16 Mbit
32 MB CAS Latency 2 SDRAM 4M x 64 16 Mbit
64 MB CAS Latency 2 SDRAM 8M x 64 64 Mbit
128 MB CAS Latency 2 SDRAM 16M x 64 64 Mbit
Memory type, size, and speed can vary between sockets, so EDO and SDRAM can be installed on
the same motherboard. Parity (x 72) DIMMs can be installed but are not recommended for the
following reasons:
• The motherboard does not provide parity checking or ECC
• Parity DIMMs cause excessive capacitive loading on memory data and address lines
1.6.1.1 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.

AN430TX Motherboard Technical Product Specification
14
1.6.1.2 SDRAM
Synchronous DRAM (SDRAM) is designed to improve main memory performance. Unlike fast
page or EDO DRAM, SDRAM is synchronous with the memory clock. This simplifies the timing
design and increases memory speed because all timing is dependent on the number of memory
clock cycles. SDRAM DIMM should meet the Intel 4-clock 66 MHz 64-bit unbuffered SDRAM
DIMM v1.0 specification.
CAUTION
The board does not support SDRAM DIMMs with an nx 4 DRAM base due to loading anomalies.
For example, a DIMM that uses sixteen 16 Mbit x 4 devices should not be used.
✏NOTE
The AN430TX supports unbuffered, 4-clock 3.3V SDRAM DIMMs only. Buffered, 5V, or 2-clock
SDRAM DIMMs cannot be used.
1.6.2 Second Level Cache
The 512 KB direct-mapped write-back L2 cache consists of two 64K x 32 global write enable
(GWE) pipeline burst asynchronous RAMs (PBSRAMs) and a 32K x 8 external tag SRAM. These
devices are soldered to the motherboard.
1.7 Chipset
The Intel 82430TX PCIset consists of the 82439TX System Controller (MTXC) device and the
82371AB PCI ISA IDE Xcelerator (PIIX4) device.
1.7.1 82439TX System Controller (MTXC)
The MTXC integrates the cache and main memory DRAM control functions and provides bus
control to handle transfers between the processor, cache, main memory, and the PCI bus. The
MTXC allows PCI masters to achieve full PCI bandwidth by using the snoop ahead feature. For
increased system performance the MTXC integrates posted write and read prefetch buffers. The
MTXC comes in a 324-pin MBGA package that features:
• Microprocessor interface control
• Integrated L2 write-back cache controller
 Supports pipeline burst SRAM
 64 MB maximum DRAM cacheability
 Direct mapped organization—write back only
 Cache hit read/write cycle timings at 3-1-1-1
 Back to back read/write cycles at 3-1-1-1-1-1-1-1

Motherboard Description
15
• Integrated DRAM controller
 8 MB to 256 MB main memory
 64-Mbit DRAM/SDRAM technology support
 3.3V EDO and unbuffered synchronous DRAM support
 Non-parity (x64) support only
• Fully synchronous minimum latency PCI bus interface
 PCI compliance (see Section 5.1 for compliance level)
 30 and 33 MHz bus speeds
 PCI to DRAM data throughput at greater than 100 MB/sec
 Up to four PCI masters in addition to the PIIX4
• Power management control
 Provides PCI CLKRUN# signal to control memory clock on the PCI bus (on/off)
 Internal clock control (gated off if no host or PCI bus activity)
1.7.2 82371AB PCI ISA IDE Xcelerator (PIIX4)
The Intel 82371AB PCI ISA IDE Xcelerator (PIIX4) is a multifunction PCI device implementing a
PCI to ISA bridge, PCI IDE functionality, a Universal Serial Bus (USB) host/hub function, and
Enhanced Power Management. The PIIX4 comes in a 324-pin MBGA package that features:
• Multifunction PCI to ISA bridge
 Supports the PCI bus at 30 and 33 MHz
 PCI compliant (see section 5.1 for compliance level)
 Full ISA or extended I/O (EIO) bus support
• USB controller
 Two USB ports (see section 5.1 for compliance level)
 Supports legacy keyboard and mouse
 Supports UHCI design guide revision 1.1 interface
• Integrated dual-channel enhanced IDE interface
 Support for up to four IDE devices
 PIO Mode 4 transfers at up to 14 MB/sec
 Supports “Ultra DMA/33” synchronous DMA mode transfers up to 33 MB/sec
 Integrated 8 x 32-bit buffer for bus master PCI IDE burst transfers
 Bus master mode
• Enhanced DMA controller
 Two 8237-based DMA controllers
 Supports PCI DMA with three PC/PCI channels and distributed DMA protocols
 Fast type-F DMA for reduced PCI bus usage
• Interrupt controller based on 82C59
 Support for 15 interrupts
 Programmable for edge/level sensitivity
• Power management logic
 Sleep/resume logic
 Supports thermal alarm
 Support for wake on modem through Ring Indicate input

AN430TX Motherboard Technical Product Specification
16
• Real-Time Clock
 256 byte battery-backed CMOS SRAM
 Includes date alarm
• 16-bit counters/timers based on 82C54
1.7.3 Universal Serial Bus (USB) Support
The motherboard features two 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
• Guaranteed bandwidth and low latencies appropriate for telephony, audio, and other
applications
• Error handling and fault recovery mechanisms built into protocol
✏NOTE
Computers that have an unshielded cable attached to the USB port might not meet FCC Class B
requirements, even if no device or a low speed (sub-channel) USB device is attached to the cable.
Use shielded cable that meets the requirements for high speed (fully rated) devices.
1.7.4 IDE Support
The motherboard has two independent bus mastering PCI IDE interfaces that support PIO Mode 3,
PIO Mode 4, ATA-33 (Ultra DMA/33), 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 like Windows†95, the bandwidth freed by bus
mastering IDE can be devoted to other tasks while disk transfers are occurring.
1.7.4.1 LS-120 Support
LS-120 MB Diskette technology enables users to store 120 MB of data on a single, 3.5-inch
removable diskette. LS-120 technology is backward (both read and write) compatible with
1.44 MB and 720 KB DOS-formatted diskettes and is supported by Windows 95 and Windows
NT†operating systems.
The AN430TX motherboard allows connection of an LS-120 compatible drive and a standard
3.5-inch diskette drive. The LS-120 drive can be configured as a boot device, if selected in the
BIOS setup utility.

Motherboard Description
17
✏NOTE
If you connect an LS-120 drive to an IDE connector and configure it as the “A” drive and
configure a standard 3.5-inch floppy as a “B” drive, the standard floppy must be connected to the
floppy drive cable’s “A” connector (the connector at the end of the cable).
1.8 Super I/O Controller
The PC87307VUL Super I/O Controller from National Semiconductor is an ISA Plug and Play
compatible (see section 5.1 for compliance level), multifunction I/O device that provides the
following features:
• Serial ports:
 Two 16450/16550A-software compatible UARTs
 Send/receive 16-byte FIFO
 Four 8-bit DMA options for the UART with Slow Infrared Support (USI)
 Ring indicator support for both serial ports
• Multimode bidirectional parallel port
 Standard mode, IBM†and Centronics†compatible
 Enhanced Parallel Port (EPP) mode with BIOS and driver support
 High-speed Extended Capabilities Port (ECP) mode
• Floppy disk controller
 DP8473 and N82077 compatible
 16 byte FIFO
 PS/2†diagnostic register support
 CMOS disk input and output logic
 High performance digital data separator (DDS)
 PC-AT†and PS/2 drive mode support
• Keyboard and mouse controller
 Industry standard 8042A compatible
 General purpose microcontroller
 8 bit internal data bus
• Support for an IrDA and Consumer IR-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
The motherboard has one 9-pin D-Sub serial port connector located on the back panel, and one
keyed 10-pin header located on the motherboard for cabling to the back panel. The 16540 and
16550A compatible UARTs support data transfers at speeds up to 921.6 Kbits/sec, while the
extended UART mode supports data rates up to 1.5 Mbits/sec.

AN430TX Motherboard Technical Product Specification
18
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-compatible)
• Bidirectional Enhanced Parallel Port (EPP) (see Section 5.1 for EPP specification compliance
level)
• Bidirectional Extended Capabilities Port (ECP)
1.8.3 Floppy Controller
The I/O controller is software compatible with the DP8473 and N82077 floppy drive controllers
and supports both PC-AT and PS/2 modes. In the Setup program, the floppy interface can be
configured for the following floppy drive capacities and sizes:
• 360 KB, 5.25-inch
• 1.2 MB, 5.25-inch
• 720 KB, 3.5-inch
• 1.2 MB, 3.5-inch (driver required)
• 1.25/1.44 MB, 3.5-inch
• 2.88 MB, 3.5-inch
1.8.4 Keyboard and Mouse Interface
PS/2 keyboard and mouse connectors are located on the back panel of the motherboard.
The 5 V lines to these connectors are protected with a PolySwitch†circuit that, like a self-healing
fuse, 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 Phoenix 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).

Motherboard Description
19
1.8.5 Infrared Support
The motherboard has a 6-pin header that supports Hewlett Packard†HSDL-1000 compatible
infrared (IR) transmitters/receivers. In the Setup program, Serial Port 2 can be directed to a
connected IR device. 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 Kbits/sec at a distance of 1 meter. See section 5.1 for IrDA specification
compliance level.
1.8.5.1 Consumer Infrared Support
The motherboard has a dedicated signal pin that supports Consumer Infrared (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. In this mode,
data rates of up to 685.57 Kbits/sec are supported. A software and hardware interface is needed to
use this feature.
1.9 Graphics Subsystem
The optional onboard graphics subsystem features the ATI-264GT Rage II+ graphics controller.
1.9.1 Graphics Controller
The ATI-264GT Rage II+ provides the following features:
• Drawing coprocessor that operates concurrently with the host processor
• Optional video coprocessor that enables simultaneous display of 24 bits per pixel (bpp) video
and 8 bpp graphics
• VGA†and VESA compatibility
• PCI compliant
• Support for power management
• Support for VESA Display Data Channel (DDC2B)
• Video scaler, color space converter, true color palette
• Triple-clock synthesizer
• Support for ATI multimedia feature connector
• 3-D graphics capability
• PCI bus master
1.9.1.1 Video Memory
The motherboard supports 2 MB of 66MHz (15 ns burst mode cycle time) SGRAM for video
memory, soldered to the board. There are no upgrade options for video memory.

AN430TX Motherboard Technical Product Specification
20
1.9.1.2 Resolutions and Refresh Rates
Table 1. ATI-264GT Rage II+ Maximum Refresh Rates at Different Resolutions
2 MB Memory Maximum Refresh Rate (Hz) At:
Resolution 4-bit Color (16 Colors) 8-bit Color (256 Colors) 16-bit Color (64K Colors) 24-bit Color (16M Colors)
640 x 480 160 160 160 160
800 x 600 160 160 160 160
1024 x 768 160 160 160 not supported
1152 x 864 160 160 160 not supported
1280 x 1024 160 160 160 not supported
1.9.1.3 Graphics Drivers and Utilities
Graphics drivers and common graphics utilities are available for Windows 3.x, Windows 95, and
Windows NT. Drivers and utilities are available from Intel’s World Wide Web site (see
Section 5.2).
1.9.2 VESA/ATI Multimedia Channel Connector
The motherboard has an optional 40-pin VESA/ATI Multimedia Channel connector that uses
26 pins for the VESA standard bus and 12 pins for the ATI Enhanced Visual Architecture bus. The
connector features a shared frame buffer interface and a Local Peripheral Bus (LPB) with a
bidirectional interface that supports video companion devices like MPEG/live video decoders.
1.9.3 Brooktree Video Capture Processor
The motherboard features an optional Brooktree Bt829A Video Capture Processor for digitizing
analog NTSC/PAL/SECAM input signals from TV tuners, VCRs, cameras, and other sources of
composite or Y/C video. The Bt829A has the mixed signal circuitry required to convert an analog
composite signal into a scaled digital video stream supporting several video formats, resolutions
and frame rates. The Bt829A features include:
• Single-chip composite/S-Video NTSC/PAL/SECAM to YCrCb digitizer
• Square pixel and CCIR601 resolution for NTSC, PAL, and SECAM
• Chroma comb filtering
• Horizontal and vertical filtered scaling
• Programmable hue, brightness, saturation, and contrast
• User-programmable cropping of the video window
• 2x oversampling
• Two-wire I2C bus interface
• 8- or 16-bit pixel interface
• Automatic NTSC/PAL format detection
• Automatic gain control