Jump to content

NEAT chipset

From Wikipedia, the free encyclopedia
(Redirected from New Enhanced AT)
Motherboard with NEAT chipset for the Intel 80286

The NEAT chipset (the acronym standing for "New Enhanced AT") is a 4 chip VLSI implementation (including the 82C206 IPC) of the control logic used in the IBM PC compatible PC/AT computers. It consists of the 82C211 CPU/Bus controller, 82C212 Page/Interleave and EMS Memory controller, 82C215 Data/Address buffer, and 82C206 Integrated Peripherals Controller (IPC). NEAT, official designation CS8221, was developed by Chips and Technologies.[1]

History

[edit]

The NEAT chipset descended from the first chipset that C&T had developed for IBM XT-compatible systems, which is based around the 82C100[2] "XT controller" chip. 82C100 incorporates the functionality of what had been, until its invention, discrete TTL chips on the XT's mainboard, namely:[3]

IBM PC compatibility is provided by C&T's 82C206 Integrated Peripheral Controller (IPC), introduced by C&T in 1986. This chip, like its predecessor the 82C100, provides equivalent functionality to the TTL chips on the PC/AT's mainboard, namely:[1]

NEAT CS8221's predecessor, called CS8220, requires five chips[4] (buffers and memory controllers) for a virtually complete motherboard, while NEAT requires four, and added support for separate ISA bus clocks.[5] The eventual successor to the NEAT chipset, 82C235 Single Chip AT (SCAT), amalgamates all of the chips of the NEAT chipset into a single chip.[6]

Other manufacturers

[edit]

Other manufacturers produced equivalent chips. OPTi, for example, produced a two-chip "AT controller" chipset comprising the OPTi 82C206 and 82C495XLC, which is found in many early 80486 and Pentium AT-compatible machines. The OPTi 82C206 is pin and function compatible with C&T's 82C206. The 82C495XLC incorporates the additional memory controller and shadow RAM support.[3]

References

[edit]
  1. ^ a b Scott Mueller (2003). Upgrading and Repairing PCs. Que Publishing. pp. 230. ISBN 9780789729743.
  2. ^ 82C100 PS/2 Model 30 and Super XT" Compatible Chip, Datasheet
  3. ^ a b Michael H. Tooley (2005). PC Based Instrumentation and Control. Elsevier. p. 32. ISBN 9780750647168.
  4. ^ CS8220 PC/AT compatible CHIPSet, Datasheet
  5. ^ Chips and Technologies Short Form Catalog 1989
  6. ^ 82C235 Single Chip AT (SCAT), Datasheet