Science Fair Project Encyclopedia
Intel 80486DX
The Intel 80486DX is a microprocessor made by Intel x86 family of processors. It is the successor to the Intel 80386 processor line.
Differences between the 80386 and 80486DX include:
- Data/Instruction Cache- An 8192-byte (8k) 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 4 matched 30 pin simms or 1 72 pin simm
The 486 has a 32 bit address bus limiting it to a 4gb of ram.
The Early 486 machines often used VL bus for video cards and hard drives The bus speed matches the motherboard frequency.
See also: Intel 80486
03-10-2013 05:06:04
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details


