DOS Days

Texas Instruments

Texas Instruments, often abbreviated simply to "TI" were a huge multinational organisation with influence across almost all technologies. Specifically in the early PC market, they were an authorised fabricator of microprocessors, and also produced integrated chipsets for XT-, 286- and 386-compatibles. At the time, they rivalled VLSI, Chips & Technologies, Headland and Suntac in the early PC chipset market.

TACT80101 Chipset

The TACT80101 was a single-chip chipset for XT motherboards. A clone of this chipset was also produced by UMC with part number UM82C088AF.

It is known to have been used on the following motherboards:

Datasheet (of the UMC clone which is pin-compatible)

TACT82000 Chipset


The TACT82000 was a 3-chip chipset for 80286 and 80386DX motherboards. It was released in December 1988. The three chips were as follows:

TACT82301 - System Unit
TACT82302 - Memory Control Unit
TACT82303 - Peripheral Control Unit

The TACT82000 chipset may also have been rebranded by ACT (Advanced Computer Technology) as the A27C001.

An article from Computer Business Review stated "Texas Instruments is now ready with its three-chip set for building MS-DOS micros, compiled in 1.2 micron CMOS from the Texas ASIC library: the set comprises the TACT82301 system unit, the TACT82303 memory control unit, and the TACT82303 peripheral control unit enabling manufacture an AT-alike motherboard to be designed with just 17 chips; products based around the set can run at up to 16MHz, and a PS/2 Model 30 version will be available soon, with chip sets to clone the Micro Channel Model 50, 60 and 80 machines to be announced shortly."

**UPDATE 15th August 2026** - Steve Wolf got in touch to let me know more about the TACT82000. It's not just a 286 chipset - it was also used on several 386DX motherboards. This is rather unique, as it means the chipset can handle both 16-bit and 32-bit CPUs. It was much more common for late 286 chipsets to be compatible only with the 16-bit 386SX [such as TI's own later single-chip TACT82411] due to their external architecture being so similar.

Steve's 286-12 PC is a Packard-Bell Axcel 1. The ROM BIOS displays 'Phoenix 80286 ROM BIOS PLUS Version 3.10 03D' during the POST, and other sources suggest the KS-11 model number on the board means it's a Samsung part, also sold in the Samsung / SEC DeskMaster 286/12 - here are some pics he provided of his machine and motherboard:


Clockwise from top-left: the Packard-Bell Axcel 1 system, motherboard, riser card, and close-up of memory banks

This chipset is known to have been used on the following systems and motherboards:

  • Olivetti PCS 286 system
  • Laser 286/3 system
  • NCR PC916 motherboard - a 286 motherboard on a card that plugs into a backplane.
  • Kentech Electronics KT-0286 v3 motherboard - runs an 80286 at 12 or 16 MHz, has DRAMs and SIPP sockets for memory expansion.
  • Packard-Bell 286X PWB-2149 (Force1 / Axcel1+) 286 motherboard - runs an 80286 at 12.5 or 16 MHz, has only SIMM sockets for memory and a single 16-bit expansion slot (or it's fitted with a riser card to expand this to more slots).
  • Informtech IT386 motherboard - a 386DX motherboard with 32 KB L2 cache (controlled with an Intel 82385 cache controller IC) and up to 16 MB of RAM in 30-pin SIMMs.
  • Delta 067-4.1-1289 386 motherboard - a 386DX motherboard with 32 KB L2 cache (controlled with an Intel 82385 cache controller IC) and up to 16 MB of RAM in 30-pin SIMMs.
  • Samsung (SEC) DeskMaster 286/12.

TACT82411 "Snake" Chipset


The TACT82411 is a single-chip AT controller. Designed for up to 33 MHz, it came in either a 3-chip chipset for SX systems or a 4-chip chipset for DX systems. The chipset comprises the TACT83442 Memory Control Unit (MCU), TACT83443 AT Bus Interface Unit (ATU), and TACT83441 Data Path Unit (DPU). It supported both the Weitek 3167 and Intel 80387 math coprocessors.

It can be seen on some Olivetti PCs. An 82S411 was also produced, codenamed "Snake+".

Datasheet (Technology Preview)

TACT83000 "Tiger" Chipset


The TACT83000 was a 386SX and 386DX chipset for systems up to 33 MHz, consisting of the following chips:

For 80386SX (3 chips):

TACT83441 - Data Path Unit (DPU)
TACT83442 - Memory Control Unit (MCU)
TACT83443 - AT Bus Interface Unit (ATU)

For 80386DX, a second DPU chip was needed as each DPU supported a 16-bit data path (the 80386DX had a 32-bit data path width).

Datasheet

 

TACT84500 Chipset


The TACT84500 was a 486 chipset introduced in 1991. It supported the EISA bus.

 

 

This page was last updated on 15th August 2026.