DOS Days

Cirrus Logic CL-GD5402

The CL-GD5402 was an ISA Super VGA chipset, also branded as AcuMOS VGA2, or AVGA2. The chip was a mild upgrade on the AcuMOS AVGA1, with AVGA2 able to support up to 512 KB of video memory and running at 65 MHz over the AVGA1's 256 KB of memory and 42 MHz.

Released August 1991
Bus ISA 16-bit
Chipset Cirrus Logic CL-GD5402 / AcuMOS AVGA2
Standards MDA, Hercules, CGA, EGA, VGA
Memory 256 KB or 512 KB DRAM (70, 80 or 100ns)
RAMDAC (Internal)
Part # -
See Also CL-GD5401

Like the AVGA1, the AVGA2 was sold on the basis of low price rather than high performance, but despite this, the AVGA2 turned out decent performance. The higher memory capacity meant the chipset could support all the AVGA1's video modes in addition to 640 x 480 in 256 colours, 800 x 600 in 256 colours and 1024 x 768 in 16 colours (non-interlaced).

Some AVGA2 cards came with 256 KB of video memory, which filled two of the four DRAM sockets, so you could upgrade at a later date to the full 512 KB.

Some AVGA2-equipped cards have a non-volatile memory chip which is used to store monitor timing selections - use the AECU utility to set these. If your card does not have an NVRAM chip, use ACU to set the monitor timings and use AVGA2CFG to recall them instead.

Commodore used the CL-GD5402 in their 386SX-25 computers. It was also used on the following cards:

  • RT-3201 (Realtek?)

Some of these cards are 16-bit ISA but still work in an XT's 8-bit ISA slot in "compatibility" mode, due to the chipset's ability to auto-sense the bus width and its support for 8- and 16-bit BIOS ROMs:



The chipset itself came in these revisions: B.
Known BIOS versions include: 1.2, 1.32



In 1991 cards using this budget chipset would have competed with the ATI VGA Charger or other cheap cards from Trident or Paradise. If you had more money you would opt for a Tseng Labs ET4000-based card such as the Diamond SpeedSTAR VGA, Everex Viewpoint VRAM, Orchid ProDesigner II, STB Powergraph ERGO-VGA, Trident Impact III, or Video Seven VRAM II.


In the Media

Setting it Up

There is no known setup configuration for cards that have a CL-GD5402 / AVGA2 chipset.


Operation Manual

Get in touch if you can provide this missing item!

AVGA2 Drivers & Utilities Disk
Version 1.1, 27 Jan 1992

Contains utilities to set monitor timings and current video/text mode, DOS drivers for AutoCAD release 9, 10, 11, AutoShade 2.0 & 3D Studio, Microsoft Word 5.0, Microsoft Windows 3.0 (16- and 256-colours), Ventura Publisher version 2.0 or GEM version 3.x, Lotus 1-2-3 version 2.x and 3.0, Lotus Symphony 2.0 Word Perfect, versions 4.2 and earlier, 5.0 & 5.1, WordStar version 3.3 and WordStar Professional 4.0, Framework II and III, Microsoft OS/2 v1.2 and Presentation Manager, ColoRIX from RIX SoftWorks, GenericCAD, and ORCAD.

AVGA2 Datasheet
August 1991

The AcuMOS AVGA2 datasheet

Version ?, 7 Jan 1992

Quadtel VGA ROM BIOS for AVGA2 cards


More Pictures

RT-3201 card with CL-GD5402 chipset