The

Tseng Labs Tseng Laboratories, Inc. (also known as Tseng Labs or TLI) was a maker of graphics chips and controllers for IBM PC compatibles, based in Newtown, Pennsylvania, and founded by Jack Hsiao Nan Tseng. Founded in 1983, Tseng Labs' first product ...

''ET4000'' was a line of

SVGA Super VGA (SVGA) is a broad term that covers a wide range of computer display standards that extended IBM's VGA specification. When used as shorthand for a resolution, as VGA and XGA often are, SVGA refers to a resolution of 800×600. History I ...

graphics controller chips during the early 1990s, commonly found in many

386 __NOTOC__ Year 386 ( CCCLXXXVI) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Honorius and Euodius (or, less frequently, year 11 ...

/ 486 and compatible systems, with some models, notably the ''ET4000/W32'' and later chips, offering graphics acceleration. Offering above average host interface throughput coupled with a moderate price, Tseng Labs' ''ET4000'' chipset family were well regarded for their performance, and were integrated into many companies' lineups, notably with

Hercules Hercules (, ) is the Roman equivalent of the Greek divine hero Heracles, son of Jupiter and the mortal Alcmena. In classical mythology, Hercules is famous for his strength and for his numerous far-ranging adventures. The Romans adapted the ...

' ''Dynamite'' series, the

Diamond Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic. Another solid form of carbon known as graphite is the chemically stable form of carbon at room temperature and pressure, ...

''Stealth 32'' and several ''Speedstar'' cards, and on many generic boards.

Models

ET4000AX

The ''ET4000AX'' was a major advancement over Tseng Labs' earlier ''ET3000'' SVGA chipset, featuring a new 16-bit host interface controller with deep FIFO buffering and caching capabilities, and an enhanced, variable-width memory interface with support for up to 1MB of memory with a ~16-bit

VRAM Video random access memory (VRAM) is dedicated computer memory used to store the pixels and other graphics data as a framebuffer to be rendered on a computer monitor. This is often different technology than other computer memory, to facilitate b ...

or ~32-bit DRAM memory data bus width. The FIFO buffers and cache functions had the effect of greatly improving host interface throughput, and therefore offering substantially improved redraw performance compared to the ''ET3000'' and most of its contemporaries. The interface controller also offered support for IBM's MCA bus, in addition to an 8 or 16-bit ISA bus. The ''ET4000AX'' could also support the emerging

VESA Local Bus The VESA Local Bus (usually abbreviated to VL-Bus or VLB) is a short-lived expansion bus introduced during the i486 generation of x86 IBM-compatible personal computers. Created by VESA (Video Electronics Standards Association), the VESA Local Bus ...

standard with some additional external logic, albeit with a 16-bit host bus width. Neither the ''ET4000AX'' or its succeeding family members offered an integrated

RAMDAC A random-access memory digital-to-analog converter (RAMDAC) is a combination of three fast digital-to-analog converters (DACs) with a small static random-access memory (SRAM) used in computer graphics display controllers or video cards to store th ...

, which hampered the line's cost/performance competitiveness later on.

ET4000/W32

Hardware acceleration via dedicated

BitBLT Bit blit (also written BITBLT, BIT BLT, BitBLT, Bit BLT, Bit Blt etc., which stands for ''bit block transfer'') is a data operation commonly used in computer graphics in which several bitmaps are combined into one using a ''Truth_table#Binary_opera ...

hardware and a hardware cursor sprite was introduced in the ''ET4000/W32''. The ''W32'' offered improved local bus support along with further increased host interface performance, but by the time PCI Windows accelerators became commonplace, high host throughput was no longer a distinguishing feature. Nevertheless, as a mid-priced Windows accelerator, the ''W32'' benchmarked favorably against competing mid-range S3 and ATI chips. Configured with 32-bit asynchronous EDO/FPM (70 ns) DRAM, the ''W32'' could sustain a transfer speed of {{cite web, title=Hattix.co.uk: Computer Hardware Museum , url=http://www.hattix.co.uk/hardware/index.php?page=video.html , date=2008, accessdate=2013-06-22, publisher=hattix.co.uk

ET4000/W32i

The /W32i revision featured an interleaved 32-bit memory bus (with 2MB+ of memory) to improve memory throughput. It supports a maximum of 4 MB of video memory, though most boards featuring the chip typically offer a maximum expansion of 2MB or less.

ET4000/W32p

The ''W32p'' model offered support for the PCI bus, although earlier revisions of this chip (prior to Revision D) had some design problems that caused sub-optimal or problematic operation when used in PCI implementations, although VLB implementations were unaffected.

References

Graphics processing units Graphics chips