AOpen AP53 User manual

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Chapter 1
Overview
The AP53 is a high-performance Pentium-based system board that utilizes
the PCI/ISA architecture. It integrates the Intel 430HX PCIset, a super I/O
controller, a PCI mode 4 enhanced IDE controller with bus master support and
a 256-KB pipelined-burst cache to enhance system performance. It also has
four single in-line memory module (SIMM) sockets that allow memory
expansion up to a maximum of 512 MB.
One main feature of AP53 is the green power-management function that
extends energy conservation from system components to display monitor. It
complies with the power-saving standards of the U.S. Environmental Protection
Agency (EPA) Energy Star program.
The AP53 board measures 220 mm x 250 mm and may come with or without a
voltage regulator module (VRM). The VRM enables the board to support future
2.5V processors.

Overview
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1.1 Board Layout
1 Power connector 14 Voltage regulator with heatsink
2SIMM sockets 15 Real-time clock and battery
3 Floppy disk drive connector 16 ISA slots
4 Parallel port connector 17 Keyboard controller
5 Primary IDE connector 18 BIOS
6 Secondary IDE connector 19 Super I/O controller
7 Intel 82439 chip 20 PCI slots
8 Pipelined-burst cache 21 COM1 connector
9 Intel 82371 chip 22 COM2 connector
10 CPU socket 23 PS/2 mouse connector
11 Two-pin fan connector 24 AT-keyboard connector
12 Multifunction connector
13 HDD LED connector

Overview
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1.2 Specifications
Microprocessor Pentium (3.3V) Processor
75/90/100/120/133/150/166/200 MHz
Memory 512 MB (maximum)
SIMM Sockets 72-pin SIMM x 4
ASICs Intel 430HX PCIset
Bus Architecture ISA, PCI
Expansion Slots Three ISA and four PCI slots
Ports One parallel port (SPP/ECP/EPP)
Two serial ports (UART 16C550)
Two-channel PCI mode 4 IDE ports
(bus master transfer support)
One floppy disk drive port
(360/720 K, 1.2/1.44/2.88 MB)
Secondary Cache 256-KB pipelined-burst cache
BIOS AMI Plug-and-Play Flash ROM BIOS
RTC & Battery Dallas DS12887A
Board Size 220 mm x 250 mm

Overview
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1.3 System Board Parts
1.3.1 Microprocessor
The AP53 system board uses an Intel Pentium (3.3V) processor running at 75,
90, 100, 120, 133, 150, 166, or 200 Hz. Chapter 2 tells how to install and
upgrade a Pentium processor.
1.3.2 ASICs
The application-specific integrated circuits (ASICs) are the Intel 82439 and Intel
82371 that belong to the Intel 430HX PCIset. This chipset allows the system to
support a higher memory (512 MB) and a pipelined-burst cache. It also offers
an error checking and correction (ECC) feature that enables the system to
detect, as well as correct the DRAM errors.
The Intel 82439 that comes in a unique ball-grid array (BGA) packaging, acts
as the memory controller data path and the DRAM data bus buffer. The Intel
82371 operates as the PCI/ISA bridge and IDE controller.
1.3.3 BIOS
The board supports the AMI basic input-output system (BIOS). The BIOS is a
program that performs the power-on self test (POST) upon booting. During
POST, this program activates the peripheral devices, tests onboard memory
and prepares the system for operation. For more information on AMI BIOS,
see Chapter 3.

Overview
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1.3.4 Expansion Slots
The board has three ISA and four PCI expansion slots. The ISA expansion
slots are the black parallel bars on the system board. The PCI slots are those
with white color and are shorter than the ISA slots. There are rows of golden
pins inside each slot that serve as a clutch to secure the contacts of the
expansion board. For information on how to install the expansion boards, see
Chapter 2.
1.3.5 DRAM Sockets
The system board has four 72-pin SIMM sockets that allow you to expand
system memory to a maximum of 512 MB. These sockets accept both single-
density and double-density SIMMs. Chapter 2 tells how to install memory
modules and the different memory configurations available.
1.3.6 Second-level Cache
The AP53 motherboard comes with an onboard 256-KB pipelined-burst
second-level cache. This pipelined-burst cache improves system performance
by shortening the DRAM read prefetch time resulting to a faster data transfer
rate.
1.3.7 Two-channel PCI Mode 4 Enhanced IDE Interface
The AP53 board integrates a two-channel PCI mode 4 enhanced integrated
drive electronics (E-IDE) interface that allows the system to support four
E-IDE devices (including hard disks with more than 528-MB capacity) via two
onboard IDE connectors (see section 1.1). This feature offers users increased
data storage capacity.

Overview
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1.3.8 Super I/O Controller
The onboard super I/O controller accommodates the following:
•Two UART 16450/16550-compatible fast serial ports
•A parallel port with standard parallel port (SPP), enhanced parallel port
(EPP) or extended capabilities port (ECP) support. Both the EPP and
ECP comply with the IEEE 1284 standards.
•3.5-inch floppy disk drives with 720-KB, 1.44-MB or 2.88-MB format.
•5.25-inch floppy disk drives with 360-KB, 1.2-MB format
1.3.9 Keyboard Connector
The onboard keyboard connector allows you to connect any AT-compatible
keyboard. See the board layout figure for the location of the keyboard
connector. Chapter 2 tells how to connect an AT keyboard.
A PS/2 keyboard connector is an option.
1.3.10 Mouse Connector
The board supports both serial and PS/2 mouse connectors. See Chapter 2 for
details on how to connect a serial and a PS/2 mouse connector.