Intel 80486DX

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The Intel 80486DX is a microprocessor made by Intel x86 family of processors. It is the successor to the Intel 80386 processor line.

Image:Intel 80486DX-33.jpg

Differences between the 80386 and 80486DX include:

  • Data/Instruction Cache- An 8192-byte (8 kB) SRAM built into the processor core, designed to store the most commonly used instructions. The 386 supported an off-chip cache, but this was much slower.
  • Pipelining- This allows the processor to handle a LocateFetchExecute each clock cycle. The pipeline is offset meaning the execute step required information from the previous two clock cycles. A locate would be to feed the next fetch, the fetch would be to feed the next execute. The 386 needs to do each step separately.
  • Virtual Memory Handler- Hardwired programming to handle swapping memory to hard drive.
  • Integrated FPU- Added accelerated high end math functions.

The 486 had a 32 bit data bus. This requires either four matched 30 pin simms or one 72 pin simm.

The 486 has a 32 bit address bus limiting it to a 4 GB of ram.

The Early 486 machines often used VESA Local Bus for video cards and hard drives. The bus speed matches the motherboard frequency.

See also: Intel 80486


List of Intel microprocessors | List of Intel CPU slots, sockets

Intel processors

4004 | 4040 | 8008 | 8080 | 8085 | 8086 | 8088 | iAPX 432 | 80186 | 80188 | 80286 | 80386 | 80486 | i860 | i960 | Pentium | Pentium Pro | Pentium II | Celeron | Pentium III | XScale | Pentium 4 | Pentium M | Pentium D | Pentium Extreme Edition | Xeon | Core | Itanium | Itanium 2   (italics indicate non-x86 processors)

eo:486DX fr:Intel 80486DX