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NEAT chipset

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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

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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

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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

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  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