The NEAT chipset (the acronym standing for "New Enhanced AT") is a 4 chip

VLSI Very large-scale integration (VLSI) is the process of creating an integrated circuit (IC) by combining millions or billions of MOS transistors onto a single chip. VLSI began in the 1970s when MOS integrated circuit (Metal Oxide Semiconductor) ...

implementation (including the 82C206 IPC) of the control logic used in the

IBM PC compatible IBM PC compatible computers are similar to the original IBM Personal Computer, IBM PC, IBM Personal Computer XT, XT, and IBM Personal Computer/AT, AT, all from computer giant IBM, that are able to use the same software and expansion cards. Such ...

PC/AT The IBM Personal Computer/AT (model 5170, abbreviated as IBM AT or PC/AT) was released in 1984 as the fourth model in the IBM Personal Computer line, following the IBM PC/XT and its IBM Portable PC variant. It was designed around the Intel 802 ...

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 Chips and Technologies (C&T), founded in Milpitas, California in December 1984 by Gordon A. Campbell and Dado Banatao, was an early fabless semiconductor company. Its first product, announced September 1985, was a four chip EGA chipset that ...

History

The NEAT chipset descended from the first chipset that C&T had developed for IBM XT-compatible systems, which is based around the 82C100 "XT controller" chip. 82C100 incorporates the functionality of what had been, until its invention, discrete

TTL TTL may refer to: Photography * Through-the-lens metering, a camera feature * Zenit TTL, an SLR film camera named for its TTL metering capability Technology * Time to live, a computer data lifespan-limiting mechanism * Transistor–transistor lo ...

chips on the XT's

mainboard A motherboard (also called mainboard, main circuit board, mb, mboard, backplane board, base board, system board, logic board (only in Apple computers) or mobo) is the main printed circuit board (PCB) in general-purpose computers and other expan ...

, namely: * 8284 clock generator * 8288

bus A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for cha ...

controller * 8254

Programmable Interval Timer In CPU, computing and in embedded systems, a programmable interval timer (PIT) is a Counter (digital), counter that generates an output signal when it reaches a programmed count. The output signal may trigger an interrupt. Common features PITs may ...

8255 The Intel 8255 (or i8255) Programmable Peripheral Interface (PPI) chip was developed and manufactured by Intel in the first half of the 1970s for the Intel 8080 microprocessor. The 8255 provides 24 parallel input/output lines with a variety of p ...

parallel I/O interface * 8259 Programmable Interrupt Controller * 8237 DMA controller *

Programmable Peripheral

Interface Interface or interfacing may refer to: Academic journals * ''Interface'' (journal), by the Electrochemical Society * '' Interface, Journal of Applied Linguistics'', now merged with ''ITL International Journal of Applied Linguistics'' * '' Int ...

(PPI) *DRAM/SRAM controller *XT

Keyboard Keyboard may refer to: Text input * Keyboard, part of a typewriter * Computer keyboard ** Keyboard layout, the software control of computer keyboards and their mapping ** Keyboard technology, computer keyboard hardware and firmware Music * Musi ...

controller 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

's mainboard, namely: * 82284 clock generator * 82288

controller * 8254

*two 8259 Programmable Interrupt Controllers *two 8237 DMA controllers *74LS612 Memory Mapper chip * MC146818

NVRAM Non-volatile random-access memory (NVRAM) is random-access memory that retains data without applied power. This is in contrast to dynamic random-access memory (DRAM) and static random-access memory (SRAM), which both maintain data only for as lon ...

/ RTC chip NEAT CS8221's predecessor, called CS8220, requires five chips ( buffers and

memory controller The memory controller is a digital circuit that manages the flow of data going to and from the computer's main memory. A memory controller can be a separate chip or integrated into another chip, such as being placed on the same die or as an int ...

s) for a virtually complete motherboard, while NEAT requires four, and added support for separate ISA bus clocks. 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.82C235 Single Chip AT (SCAT)
Datasheet

Other manufacturers

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 Pentium is a brand used for a series of x86 architecture-compatible microprocessors produced by Intel. The original Pentium processor from which the brand took its name was first released on March 22, 1993. After that, the Pentium II and P ...

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.

References

{{reflist IBM PC compatibles Chipsets