Universal Abit

Abit was a motherboard manufacturer for the IBM PC and its compatibles during the DOS era, founded in 1989 and headquartered in Taipei, Taiwan.

 

AB-AG4

Year: ?
Type: Socket
Form Factor: ?
Chipset:
Slots: 7 x ISA (1 x 8-bit, 6 x 16-bit), 3 x VLB.
Memory:
BIOS:
Known Revisions:

 

AB-AN4

Year: 1993
Type: Socket 2
Form Factor: Baby AT (260mm x 220mm)
Chipset: SiS 461/407
Slots: 6 x ISA (16-bit), 3 x VLB
Memory: 8 x 30-pin SIMM, 2 x 72-pin SIMM (max. 64 MB)
BIOS:
BIOS Strings:
40-01CI-001247-00101111-080893-SIS461-H
Known Board Revisions: 0.2

The AN4 supports Intel 80486 SX, DX, and DX2 CPUs from 25 MHz up to 66 MHz, and Pentium OverDrive. Maximum FSB speed is 66 MHz.

L2 cache sizes are 128 KB, 256KB and 512 KB.

AB-AR5

Year: 1996
Type: Socket 7
Form Factor:
Chipset: Intel 430VX Triton II
Slots: 4 x ISA (16-bit), 4 x PCI.
Memory: 4 x 72-pin SIMM (2 banks), 2 x 168-pin DIMM, 128 MB max.
BIOS: Award 4.51PG

Supports Intel Pentium P54C and P55C (MMX) CPUs, as well as AMD K5 and Cyrix 6x86. The board uses "Soft Menu", allowing all configurations to be done via the BIOS (no DIP switches or jumpers).

CPU Speeds supported from 75 - 200 MHz (Pentium), 75 - 100 MHz (AMD), and 6th gen Cyrix 6x86 (P120+, P133+, P150+, P166+, and P200+).

User Manual


AB-AX5

Year: 1997
Type: Socket 7
Form Factor: ATX
Chipset: Intel 430TX
Slots: 3 x ISA (16-bit), 4 x PCI
Memory: 4 x 72-pin SIMM (2 banks), 3 x DIMM.
BIOS: Award
Known Revisions: 2.2.

Comes with 512KB L2 cache onboard. Bus frequencies from 50 to 83 MHz. CPU core voltage support is 3.2V, 2.9V, 2.8V, 2.7V and 2.5V.

From Tom's Hardware review:
"At 83 MHz, this board is one of the fastest, at normal bus speeds it is better than average. This board features ’Soft Menu ’, it’s an extension to the Award BIOS 4.51PG, which allows to set the CPU and bus frequencies in the system BIOS. This seems to be made for playing with the different possibilities. Let run your favorite application or OS with 75 or in some cases 83 MHz system bus speed, and write your recordable CDs at safe 66 MHz. Without opening your case, isn’t it great ? As in the prior socket 7 review already mentioned, this board has some difficulties with certain types of SDRAM, e.g. the older Corsair modules won’t work properly. If you are looking for an ATX board to run at the highest possible external clock speed, think about the AX5."

 

AB-BH6

Year: 1998
Type: Slot 1
Form Factor: ATX
Chipset: Intel 440BX (Seattle)
Slots: 2 x ISA (16-bit), 5 x PCI, 1 x AGP 2x
Memory: 3 x 168-pin DIMM supporting SDRAMs of PC-66 or PC-100. It supports parity and ECC RAM.
BIOS: Award Modular BIOS v4.51PG
Known Revisions: 1.02

Suitable for Pentium II (Klamath and Deschutes), Pentium III (Katmai and Coppermine*), and Celeron (Covington, Mendocino, and Coppermine*)

*Coppermines over 700 MHz only from with BH6 v1.1 or v1.2.

The BH6 supports front side bus speeds from 66, 75, 83, 100, 103, 112, 124 and 133 MHz. It supports CPU clock multipliers of 2.0x through to 5.5x, and CPU voltage ranges from 1.30V up to 3.2V in 0.1V or 0.05V increments.

 

It's a jumperless setup, thankfully, due to Abit's SoftMenu II.

 

 

AB-BX6

Year: Spring 1998
Type: Slot 1
Form Factor: ATX
Chipset: Intel 440BX (Seattle)
Slots: 3 x ISA (16-bit), 4 x PCI, 1 x AGP 2x
Memory: 4 x 168-pin DIMM supporting SDRAMs of PC-66 or PC-100.
BIOS: Award Modular BIOS v4.51PG

The BX6 was ABit's successor to the LX6, which had problems with many PCI and ISA cards, plus a serious keyboard problem. Unlike most other boards out around this time, this one doesn't come with the SBLink header.

If you have issues with ISA network cards on this motherboard, make sure you're running the latest BIOS version as there were compatibility issues in earlier versions.

You can select FSB speed from 66 up to 133 MHz under the 'CPU SoftMenu' BIOS (ABit actually call this SoftMenu II) option. Under here you can also choose the CPU core voltage. All in all, it's a good board for overclockers, despite the lack of any RAM timing options in the BIOS.

 

AB-IT5H

Year: 1997
Type: Socket 7
Form Factor: AT
Chipset: Intel 430HX
Slots: 4 x ISA (16-bit), 4 x PCI
Memory: 4 x 72-pin SIMMs, 2 x 168-pin SIMMs (both support EDO and FP DRAM). Also has 512 KB built-in SRAM. Maximum memory supported is 512 MB.
Known Revisions: 1.5, 2.0

Supports Pentium and Pentium MMX, AMD K5 and K6, Cyrix 6x86, 6x86MX PR150-PR200 processors. Core voltage support for 3.2V, 2.9V, 2.8V and 2.7V. The board has two TAG RAMs to support a cacheable area of up to 512 MB.

FSB speeds range from 50 MHz up to 83 MHz.

Does not support the AMD K6-2+ or K6-III+ due to the lack of a low enough voltage selection. This of all boards months ago was the first running perfectly even at 83 MHz bus speed. By the way, the memory timings were all switched to 'maximum warp' without errors. This means quite good performance under Windows 95; Windows NT is a bit slower, also the usage of a 6x86MX CPU. But its performance is comparable to some boards with the 430TX chipset! The latest revision 2.0 now has switching regulators; if you should own a IT5H, don't think about upgrading to a TX chipset board, you probably won't get much more performance, especially in case you're using over 64 MB RAM.

 

AB-PH5

Year: 1995?
Type: Socket 7
Form Factor: AT
Chipset: SiS 5511/5512
Slots: 3 x ISA (16-bit), 4 x PCI
Memory: 4 x 72-pin SIMMs
BIOS: Award
BIOS Dates: 12/08/95
Known Board Revisions: 1.1, 1.3

Supports Cyrix 6x86 CPUs. Must have Sync L2 set, and Linear Burst mode. Supports up to 128 MB of RAM. Cache sizes available are 256 KB and 512 KB.

Click here for more configuration info for this motherboard.

 

AB-PN5

Year: 1996
Type: Socket 7
Form Factor: AT
BIOS: Award
BIOS Dates: 04/17/96
Known Board Revisions: 1.2

Supports Cyrix 6x86 CPUs from P120+ up to P166+.

 

 

AB-PR5

Year: 1995?
Type: Socket 7
Form Factor: AT
Chipset: Intel 430VX
Known Revisions: v1.1
BIOS: Award
BIOS Dates: 04/30/96

Supports Cyrix 6x86 P120+ to P166+ CPUs on BIOS dated 04/30/96, but require the 10A voltage regulator.

 

 

AB-PT5

Year: 1995?
Type: Socket 7
Form Factor: AT
Power Connector: AT
Chipset: Intel 430FX
Known Revisions: v1.0, v2.11
BIOS: Microid Research MR BIOS v3.46
BIOS Dates: 02/02/96

Supports Cyrix 6x86 P133+ and P166+ CPUs on BIOS dated 02/02/96, but require the 10A voltage regulator.

 

 

AB-PX5

Year: 1997
Type: Socket 7
Form Factor: Baby AT
Power Connector(s): AT
Chipset: Intel 430TX
Slots: ISA (4), PCI (4)
Memory: 2 x SIMM, 2 x DIMM.
BIOS: Award
Known Revisions: 1.14c.

Comes with 512KB L2 cache onboard. Bus frequencies from 50 to 83 MHz. CPU core voltage support is 3.2V, 2.9V, 2.8V and 2.5V.

From Tom's Hardware review:
"This board seems to support 75 and 83 MHz bus clock, but I had some trouble with it, even with our latest revision 1.14c. This expressed in hangups and protection errors under Windows 95 as well as blue screens under Windows NT. Particularly the old Corsair memory didn’t want to work properly over 66 MHz. In spite of these problems, performance is not bad at all and the overall results at 66 MHz are satisfactory. Except with the 6x86MX, the board is slower under Windows NT. Maybe a new BIOS can bring the estimated stability at 83 MHz bus."

 

AB-SM5

Year: ?
Type: Socket 7
Form Factor: ATX
Chipset: Intel 430VX
Slots: ISA (4 x 16-bit), PCI (3)
Memory: 4 x 72-pin SIMM (2 banks), 2 x 168-pin DIMM.
BIOS: Award 4.51PG
Known Revisions: 1.01

AB-TX5

Year: 1997
Type: Socket 7
Form Factor: AT
Power Connector(s): AT and ATX
Chipset: Intel 430TX
Slots: ISA (3), PCI (4)
Memory: 4 x SIMM, 2 x DIMM.
BIOS: Award
Known Revisions: 1.0.

Bus frequencies: 50 - 83 MHz.
Core voltages: 3.2V, 2.9V, 2.8V, 2.7V and 2.5V.

From Tom's Hardware review:
"ABit's newest TX chipset board, the AB-TX5, seems to inherit the crown of the AT boards most suited for overclockers and speed fans: It's fast, faster and the fastest. Featuring 'Soft Menu', it's very easy to adjust CPU clock ratio. External frequencies are supported up to 83 MHz, very stable by the way. Even the Pentium 233 MMX ran fine at 291 MHz and 3.2 Volts! It's good to see that the performance of the AB-PX5 was improved much more as well. This is my personal favorite TX board by the way. A new board must first be reliable and stable for me under all circumstances. And if it's fast, too, I got my candidate. ABit's TX5 board fits exactly my personal expectations. Please don't forget that there are more fine boards as well; before you make your choice, go ahead and read some other reviews as well. Maybe you will find some fact or feature you will regard even more important than I do."