AOpen

AOpen, a subsidiary of Acer, was a manufacturer of motherboards and sound cards for the IBM PC and its compatibles during the latter few years of the DOS era, first founded in late 1996.

Based in Taipei, Taiwan, they started as the "Open System Business Unit" of Acer Computer Inc. Today they specialise in ultra small form factor platforms. Their website can be found at https://www.aopen.com/.

 

Motherboards

AP53

Year: 1996
Type: Socket 7
Form Factor: Baby AT
Power Connector: AT
Chipset: Intel 430HX
Expansion: 3 x 16-bit ISA, 4 x PCI
Memory: 4 x 72-pin SIMM (ECC and non-ECC). Max 512 MB.
BIOS: AMI PnP
BIOS Dates: 06/13/96
Known Board Revisions: 3.0

This board supports Cyrix 6x86 P120+ up to P166+ CPUs. Supports 66 MHz FSB. Comes with 512 KB of L2 cache onboard.

User Manual

AP55CS

Year: 1996
Type: Socket 7
Form Factor: Baby AT
Power Connector: AT
Chipset: SiS 5501/5502
Expansion: 4 x 16-bit ISA, 4 x PCI
Memory: 4 x 72-pin SIMM (ECC and non-ECC). Max 128 MB.
BIOS: Award PnP
BIOS Dates:
Known Board Revisions:

Supports AMD K5 and K6, Cyrix M2, and Intel Pentium.
66 MHz FSB.
256 KB L2 cache onboard.
Single USB 1.1 port.

User Manual

 

AP57

Year: 1996
Type: Socket 7
Form Factor: Baby AT
Power Connector: AT
Chipset: SiS 5571
Expansion: 4 x 16-bit ISA, 4 x PCI
Memory: 4 x 72-pin SIMM
BIOS: Award PnP

This board supports Pentium P54C, Pentium MMX 150-233 MHz, Cyrix 6x86 P120+ up to P166+, AMD K5 from PR90 up to PR166, and K6 PR166/PR200.

CPU core voltage ranges from 2.5V - 3.45V.
FSB speed is 66 MHz only.
Comes with 512 KB of L2 cache onboard.
A single USB 1.1 port is available.

For Cyrix chips, a jumper on the board (JP22) can be used to set Linear Burst Mode on.

User Manual

 

AP5S

Year: 1996
Type: Socket 7
Form Factor: Baby AT
Chipset: SiS 5511
Expansion: 4 x 16-bit ISA, 4 x PCI
Memory: 4 x 72-pin SIMM. Max 256 MB.
BIOS: Award PnP
BIOS Dates: Rev 1.2
Known Board Revisions: 2.0

This board supports Cyrix 6x86 P120+ up to P166+ CPUs, AMD K5 and K6, and Cyrix M2.
FSB speed is 66 MHz only.
Comes with 256 KB of L2 cache onboard.
A single USB 1.1 port is available.

User Manual

 

AP5T

Year: 1997
Type: Socket 7
Form Factor: ATX
Chipset: Intel 430TX
Slots: ISA (3 x 16-bit), PCI (4)
Memory: 4 x SIMM, 2 x DIMM
BIOS: Award
Known Revisions: 3.1

This board comes with 512 KB L2 cache onboard. This 430TX chipset board features CPU temp monitoring, 512 KB L2 Cache, 2x DIMM, 4x PS/2 sockets, 3x ISA / 4x PCI slots and outstanding quality. This boards runs stable up to 83 MHz, but strangely I had to switch the K6-233 down to 2.9 Volts (!) to run reliably at 250 MHz with the Toshiba SDRAM. The Shuttle HOT-565 has similar features but no switching voltage regulator. AOpen seems to become a reliable manufacturer for 83 MHz boards just the way ABit is doing with the AB-TX5. Both boards support Ultra DMA/2, 64 MB cacheable area (SDRAM or EDO), no ECC support. If you want to use the 233 MHz K6 processor, be aware you get rev. 3 or newer, because you will need 3.2 V support for this CPU. Revision 3.1 also has jumper settings for 2.2 Volts, which the K6 266 most likely will tolerate. The performance of the AOpen TX chipset boards is fine once again, particularly with the K6.

Core voltage support: 3.2V, 2.9V, 2.8V, and 2.2V.

 

 

AP5VM

Year: 1997
Type: Socket 7
Form Factor: Baby AT
Chipset: Intel 430VX Triton II/III
Slots: 3 x ISA (16-bit), 4 x PCI.
Memory: 4 x SIMM (2 banks), 2 x DIMM,
BIOS: AMI WinBIOS

CPU clock speeds from 75 - 200 MHz, bus speeds of 50 or 66 MHz.

User Manual
User Manual (Revisions 2xx and 3xx)

 

 

AX5T

Year: 1997
Type: Socket 7
Form Factor: ATX
Chipset: Intel 430TX
Slots: ISA (4 x 16-bit), PCI (4)
Memory: 4 x SIMM, 2 x DIMM
BIOS: Award
Known Revisions: 3.0

Revision 3 has some voltage selection jumpers that are probably reserved for 2.1 or 2.2 V core voltage. Thanks to the 430TX chipset it features the same limitations (64 MB cacheable, no ECC) and advantages (UDMA/2, SDRAM support). Its performance is good, as with the AP5T. Other manufacturers should take a look at some of the AOpen features, e.g. the admirable stability at 75 and 83 MHz bus speed; you can say it's more stable than fast at 83 MHz. The only comparable boards are the ABit AB-TX5 and partially the Shuttle HOT-565/569.

Supported bus frequencies are 60-83 MHz.

User Manual

AX6B

Year: Spring 1998
Type: Slot 1
Chipset: Intel 440BX (Seattle)
Form Factor: ATX
Power Connector: ATX
Slots: 3 x ISA (16-bit), 4 x PCI, 1 x AGP
Memory: 3 x 168-pin DIMM (Max 768 MB). Supports PC-66 and PC-100.
BIOS: Award

A decent 440BX motherboard with no compatibility issues, can run almost any type of SDRAM, and supports FSB settings from 66 up to 133 MHz.

 

AX6BC

Year: 1998
Type: Slot 1
Form Factor: ATX
Power Connector: ATX
Memory: 3 x 168-pin DIMM (Max 768 MB).
BIOS: Award

Supports the following CPUs: Intel Pentium II 233 to 400 MHz, Pentium III 450 to 700 MHz, and Intel Celeron 300A, 366, and 400.

The memory slots support SDRAM and buffered SDRAM modules.

User Manual

 

AX37 Plus / AX37 Pro

Year: 199?
Type:
Form Factor:
Chipset:
Slots:
Memory:
BIOS:

User Manual

 

 

 

MX59 Pro

Year: ?
Type: Socket 7
Form Factor: ?

 

Sound Cards

FX-3D / Plus

Year: 1996
Type: 16-bit ISA
FM synthesizer:
Audio codec: Analog Devices AD1816JS SoundPort
Known Revisions: A

This is a Plug & Play card with a wavetable header.
Drivers exist for Windows 3.1, 95 and 98.

I'm guessing but the Plus variant is likely the one that got the built-in Samsung KS0164 "Omniwave" wavetable synthesizer chip which had 32 voices and offered General MIDI, GS and Roland MT-32 compatibility.

The other empty IC pads on these pics would have been for the KS0174 ROM chip which came in 1, 2 and 4 MB capacities for sample storage.

 

 

 

FX-3D Pro Radio

Year: 2000 ?
Type: 16-bit ISA
FM synthesizer: OPL3-compatible
Audio codec: Analog Devices AD1816JS SoundPort
Known Revisions:

Compatibility: Ad Lib, Sound Blaster, Sound Blaster Pro, Windows Sound System.

The FX-3D Pro Radio was essentially the same FX-3D Plus card, but with an onboard FM radio receiver. This came with software that allowed automatic scanning of radio stations, or stepping in 5 kHz steps across a frequency band of 87 - 108 MHz. You could then store preset frequencies for easier return to your favourite stations later. The software also allowed for recording of radio audio to a .WAV file.

Game/MIDI port is MPU-401 compliant.
Signal-to-noise ratio is above 80 dB.

Software Included:
AOpen Rack (Audio Play Back & Editing Software for Windows)

AOpen Radio (Digital Panel for Radio Station Tuning and Setting)