Tseng Labs

Tseng Labs was a graphics card and chipset manufacturer for the IBM PC and its compatibles from 1983 to December 1997. They were best-known for the Tseng Labs ET3000, Tseng Labs ET4000 and Tseng Labs ET6000 VGA-compatible graphics chips, which were highly popular between 1990 and 1995 (the era of Windows 3.x). The company's ET4000 family was noteworthy for its unusually fast host interface (ISA) throughput, despite having a conventional DRAM framebuffer.

Tseng moved from being a retail / commercial board supplier to OEM seller of their graphics chips. Ultimately, Tseng Labs' VGA controllers were found in PCs from major system and board companies including Compaq, Dell, IBM, NEC, STB Systems, Diamond Multimedia and several major Taiwanese add-in brands.

During the mid-1990s, they lost market share to S3 and ATI, partly because they were especially late in integrating a RAMDAC into their products, which damaged its competitiveness in a very crowded market. While they were attempting to develop their first 3D engine (the ET6300) and falling very short on R&D funds, they eventually chose to abandon new products and seek a buyout - they were bought by ATI Technologies in December 1997.



Launched: 1984
Bus: ISA 8-bit / Embedded.
Price: ?

Tseng Labs' ET1000 was an EGA-compatible card with 64 KB video RAM. It had both TTL output (9-pin D-SUB), and an LPT (printer) port.

ET1000 "UltraPak"

MDA,CGA and Hercules compatible. 132-column text modes. For monochrome monitors only.



CGA compatible. Adds proprietary 400 line modes and up to 8 on screen colours.


"EVA" and "EVA/480" (ET2000)

Released: Oct 1986
Initial Price: $499

An EGA-compatible card from late 1986 which used their own developed VLSI (Very Large Scale Integration) ET2000 chipset. Many video card manufacturers at the time were using Chips & Technologies' EGA chipset on their cards. This was the first card to offer an extended 480-line EGA graphics mode. Hardware accelerated windowing, panning, and zooming is also supported.

These extensions to the IBM EGA standard were considered risky or brave in 1987, in case they used registers that IBM might use later as a 'Super EGA'.

It also got the useful 132-column text modes and came bundled with drivers to support this for the most popular applications such as Lotus 1-2-3 Release 2.0, Symphony v1.1 and AutoCAD. These permitted 132 x 25, 132 x 28 and 132 x 44 line modes. Fonts could also be 6, 8, 9, 10, 12 and 16 dots wide, whereas the EGA standard could only do 8 and 9.

The EVA/480 got an additional two modes over the standard EVA card, which require an NEC Multisync (or similar) monitor:

  • 640 x 480 graphics mode
  • 80 x 60 text mode

It also came bundled with a copy of Dr. Halo II. The EVA/480 also came with the CMII module, which manages CGA and Hercules compatibility. This module was an option on the EVA.

These EVA cards are very long, requiring a full-length ISA slot.

Compared to rivals at the time from Paradise Systems (AutoSwitch), QuadRAM (QuadEGA ProSync), IDEAssociates (All Aboard) and Overboard) and Video 7 (VEGA Deluxe), the EVA and EVA/480 video BIOS routines ran much slower, though 'direct to screen' performance was the best of the pick.



Launched: 1989
Bus: ISA 16-bit
Memory: 512 KB (100ns)
RAMDAC: unknown (8-bit colour)
RAMDAC Speed: 50 MHz
VESA Standard: No
FCC ID: unknown
BIOS Dates: 08/10/90
Known BIOS Versions: v8.01

The ET3000 was a Super-VGA card with register-compatibility with VGA, EGA, CGA, MDA and Hercules standards.

In addition to standard VGA, the chipset provides the following high resolutions:

  • 640 x 480, 256 colours from a palette of 256,000.
  • 800 x 600, 16/256 colours from a palette of 256,000.
  • 1024 x 768, 16 colours from a palette of 256,000 (interlaced and non-interlaced).

It also supports a high-resolution text mode of 132 x 25/28/44 lines, which was popular for business users of Lotus 1-2-3, Lotus Symphony, WordPerfect, or to emulate the IBM 3278 and DEC VT100 terminals.

The first picture is an original ET3000AX 8-bit ISA card.

The second picture is an Optima 1024 Model 3071 Revision A, which contains the Tseng Labs ET3000AX chipset, 512 KB RAM.

The ET3000 had a high level of compatibility, and in 286s this card was a common option, with its maximum capacity of 512KB RAM it could display a maximum resolution of 1024 × 768 pixels. The card has the usual EGA digital TTL (9-pin D-SUB) and VGA analog (15-pin D-SUB) connections, as well as an "option" connector on the top.


User Manual (for the Qtec VGA1024 card, which uses ET3000)


Launched: 1989.
Bus: ISA 16-bit or VLB
Memory: 512 KB or 1 MB DRAM (70ns or 80ns)
RAMDAC: "MUSIC" 9C1710, ICS5301-1 or ICS5301-2
RAMDAC Speed: 66 MHz, 80 MHz, 110 MHz
VESA Compatibility: Yes, v1.32
Known BIOS Dates: 09/14/90, 12/21/90, 08/17/92, 09/30/93, 01/20/94
Known BIOS Versions: v8.00, v8.02

Very fast frame buffer.

The ET4000AX chipset was considered one of the fastest performing in its time, despite being "unaccelerated".The first picture below is a rare OPTi bus slot card (requires an OPTi chipset motherboard with OPTi slot(s)).

For DOS, the ET4000 cards had issues with some games including Commander Keen 4 and up.

Many ET4000AX-based cards come with the common "MUSIC" chip which is a DAC with an 8-bit colour depth. Later cards that come with an ICS5301-1 or ICS5301-2 support TrueColor (24-bit colour depth).

Tseng licensed their chipset to Gainward, STB Systems, Genoa, Diamond, EVGA, Gigabyte and more.

The ET4000 chipset is also found on:

Click here for the datasheet, or here for the Data Book from 1990.

More Images



Launched: 1993
Bus:VL Bus and PCI
Memory: 1 MB DRAM (70ns)
RAMDAC: Winbond W82C490-80
RAMDAC Speed: 80 MHz
Known BIOS Dates: 01/07/93
Known BIOS Versions: v8.00

Similar to ET4000AX, but with 32-bit windows graphics acceleration.

The W32 was Tseng's first VESA Local Bus-based card, though it was later released in PCI form also.

Found on the following:

  • MachSpeed VGA GUI 2400S

More Images


Launched: -
Bus: ISA or VESA Local Bus
Chipset: Cirrus Logic CL-GD5422-75

Similar to ET4000W32, but with support for interleaved DRAM when configured with 2MB. DRAM interleaving provided roughly 85% of the throughput of a true 64-bit interface.

Found on the following:

  • MachSpeed VGA GUI 2400+
  • Hercules Dynamite Pro


Click here for the datasheet.




Similar to ET4000W32i, but with support for PCI.

Found on the following:

  • Hercules Dynamite Pro
  • STB Lightspeed
  • Diamond Stealth 32

Click here for the datasheet.



Launched: 1996
Bus: PCI
Price: ?
64-bit graphics accelleration with 2 or 4.0MB of MDRAM. Integrates RAMDAC into the graphics core. Core clocked at 135 MHz, 128-bit internal, 92 MHz memory frequency, 500 MB/s memory transfer speed.

For DOS, ET6000 cannot do "mode x" properly, so breaks compatibility with a few games like Jazz Jackrabbit.



Improves the integrated RAMDAC to address problems with blurriness at higher resolutions. Uses faster MDRAM.




Was to be Tseng's first 3D-capable chipset. Not completed before Tseng chose to sell up. No known specimens have been spotted in the wild.