DOS Days

Cirrus Logic CL-GD5422 / CL-GD5424 / CL-GD5425

The CL-GD5422 was a Super VGA chipset released in 1992. It came in three variants: CL-GD5422 for the 16-bit ISA bus and CL-GD5424 and CL-GD5425 for the VESA Local Bus. The advantage of these over the 5420/5421 was its 32-bit memory bus.

Released 1992
Bus ISA 16-bit (5422) or VESA Local Bus (5424 or 5425)
Chipset Cirrus Logic CL-GD5422, CL-GD5424 or CL-GD5425
Standards MDA, Hercules, CGA, EGA, VGA
Memory 256 KB, 512 KB or 1 MB FPM DRAM (70, 80 or 100ns)
RAMDAC (Internal)
Part # -
See Also CL-GD5420 / CL-GD5421, CL-GD5426

The core clock on the 5422/4/5 ran at 80 MHz with memory clocking in at 50 MHz. The chipset offered no GUI acceleration features found in the more advanced CL-GD542x cards from the CL-GD5426 and up. The maximum resolution supported by the chipset was 1024 x 768 (interlaced or non-interlaced) in 256 colours.

The CL-GD5422/4/5 were an enhanced version of the CL-GD5420, with a 32-bit memory bus and 15/16/24-bit RAMDAC, so supported True Color (16.7 million colours).

They all supported hardware acceleration for both 8-bit and 16-bit color depths. At the time of launch, they were one of the lowest-priced SVGA controllers to support both.

A VESA Local Bus version of the 5422 is called the CL-GD5424 - it was Cirrus Logic's first VLB card. There is at least one anomaly I've noticed - the Ahead AVGA-A3 card listed below is a 16-bit ISA card that uses the CL-GD5424. The 5424 provides a VESA local bus width but is fully backward-compatible to run on the 16-bit ISA bus too, so if parts were in short supply, CL may have offered up 5424s in place of 5422s. Can anyone clarify?

The CL-GD5425 was the same as the CL-GD5424 but also got a TV out connector. This was able to scale a full VGA display (640 x 480) into a TV viewing area while maintaining a correct aspect ratio. Memory frequency was increased to 60 MHz to supplement this additional functionality.

Found on:

  • Gainward VGA-GWV27 (FCC ID: ICUVGA-GWV27) - max. resolution 1024x768
  • Sigma Designs WinStorm
  • STB Systems Evolution VGA
  • Aamazing Designs Aamazing VGA 1000
  • Ahead AVGA3-22-1M (FCC ID: 17TGD5422DM2 / I7TGD5422DM2)
  • Pine Technology PT-521/3 (FCC ID: J6QGD5422DM2)
  • Pine Technology PT-524/8G (FCC ID: J6Q4LVLDM7)
  • RT3204
  • Unknown brand (FCC ID: GC8LA524)
  • Puretek Industrial PT-2036 (FCC ID: HT52-PT-2036)

The CL-GD5424 was also the integrated VGA chipset used on AST Bravo 486 computers.

Here is a summary of the Cirrus Logic CL-GD542x range so you can compare each chipset's differences from one another:

  5420 5421 5422 5424 5425 5426 5428 5429
GUI Acceleration - -         Enhanced BitBLT MM I/O
Max. Video Memory 1 MB 1 MB 1 MB 1 MB 1 MB 2 MB 2 MB 2 MB
Memory Bus Width 16-bit 16-bit 32-bit 32-bit 32-bit 32-bit 32-bit 32-bit
Core Clock Frequency 75 MHz 75 MHz 80 MHz 80 MHz 80 MHz 80 MHz 80 MHz 86 MHz
Memory Clock Frequency 50 MHz 50 MHz 50 MHz 50 MHz 60 MHz 50 MHz 50 MHz 60 MHz
Max. Resolution at 256 Colours 1024 x 768 (NI) 1024 x 768 (NI) 1024 x 768 (NI) 1024 x 768 (NI) 1024 x 768 (NI) 1280 x 1024 1280 x 1024 1280 x 1024



The chipset itself came in these revisions: C.



In direct competition with the CL-GD5422 and 5424/5425 were the Tseng Labs ET4000


In the Media

There is nothing available in the media on this chipset.

Setting it Up

There is no known setup configuration for cards that have a CL-GD5422 / CL-GD5424 / CL-GD5425 chipset.


Operation Manual

Get in touch if you can provide this missing item!

CL-GD5422 Drivers
(From 5422 Evaluation Board)

Courtesy of Andy Welburn of AndysArcade

CL-GD542x Databook
Version 7, May 1995

Provides technical information on the entire range of CL-GD542x graphics chipsets.

(From 5422 Evaluation Board)

Odd and Even BIOS ROM chip dumps, courtesy of Andy Welburn of AndysArcade


More Pictures

Images of a CL-GD5422 Evaluation Board, courtesy of Andy Welburn of AndysArcade

Ahead AVGA3-22-1M with an FCC ID of 17TGD5422DM2 or I7TGD5422DM2

Pine Technology PT-521 / PT-523 with an FCC ID of J6QGD5422DM2

PureTech Industrial PT-2036 VLB card with an FCC ID of HT52-PT-2036

An unknown brand of card with an FCC ID of GC8LA524