Suntac were a Japanese motherboard chipset manufacturer for PC compatibles during the 80286 era. They were direct rivals of the likes of Chips & Technologies, VLSI, Texas Instruments and Headland Technology in the early PC chipset market.




The SUNTAC-62 chipset was designed for use with 80286 motherboards up to 12 MHz.

The chipset consisted of the following:

  • ST62BC001-B - System Controller
  • ST62BC002-B - High Address Bus Controller/Decoder
  • ST62BC003-B - Low Address Bus Decoder
  • ST62BC004-B - Data Bus Controller
  • ST62BC005-B - DMA Page Address Register
  • ST62BC006-B - Peripheral Interface Controller

The System Controller handles clock generation (PROCCLK, SYSCLK and DMACLK), DRAM timing and wait states for I/O operations. The High Address Bus Controller manages 8 address lines, RAS/CAS generation for DRAMs. The Low Address Bus Controller handles the lower 8 address lines. It also handles the clock generation for video circuitry. The Data Bus Controller manages the system and memory buses. The DMA Page Address Register manages the EMS control register, DMA pages and address logic, decodes I/O addresses, handles Non-Maskable Interrupts and provides support for the 80287 math co-processor. Finally, the PIC provides support for serial and parallel ports, keyboard decoding, and more.

This chipset is known to be used with AWARD or Phoenix BIOS.

A number of 80286 motherboards used the ST62 chipset: