DOS Days

Cirrus Logic CL-GD5401

The CL-GD5401 was an ISA Super VGA chipset, also branded as AcuMOS VGA, or AVGA1. The chip first appeared prior to the AcuMOS acquisition by Cirrus Logic in 1992. It's not 100% clear, but the design of the chipset was likely done by AcuMOS (who called it AVGA1) and CL entered into an agreement to resell it under the CL branding before they bought the company. This would explain why some had the Cirrus Logic branding while others had AcuMOS AVGA1 branding.

	Released	1991
	Bus	ISA 16-bit
	Chipset	Cirrus Logic CL-GD5401 / AcuMOS AVGA1
	Standards	MDA, Hercules, CGA, EGA, VGA
	Memory	256 KB DRAM (70 or 80ns)
	RAMDAC	(Internal)
	Part #	-
	FCC IDs
	Cards
	See Also	CL-GD5402

The CL-GD5401 was the first fully-integrated VGA chip to market, with a built-in RAMDAC and clock generators, meaning the the only external chips required to build a graphics cards were video memory and a VGA BIOS.

The chipset's core clock ran at 42 MHz, with memory running at either 37.5 MHz (if 80ns DRAMs are used) or 44.7 MHz (if 70ns DRAMs are used).

They were sold on the basis of low price rather than high performance, but despite this the CL-GD5401/AVGA is a decent performer for an ISA graphics chipset.

Found on the following cards:

EIZO VA30
Everex Systems Viewpoint Standard (EV-628)
Boca Research (FCC ID: EUD-5U9-BRI4390)
KT-AVGA1-V2
United Solutions AVGA1 (FCC ID: JGV31000)
Cornerstone ImageAccel PC161i
FCC ID: IWLVGAADAPTER1V1
FCC ID: JA8223G/V1
FCC ID: JA8223G/V2
FCC ID JAX8223A/V1 (see images below)

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:

Revisions

The chipset itself came in these revisions: B.

Competition

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.