Notes:
P23 - Intel 486SX
P23S - Intel 486SX SL enhanced
P23N - Intel 487SX Math Coprocessor
ODP - Intel 486 OverDrive (P23T)
ODP-S - Intel 486 OverDrive SL enhanced (P23T)
ODPR - Intel 486 OverDrive Replacement (P4T)
ODPR-S - Intel 486 OverDrive Replacement SL enhanced (P4T)
P4 - Intel 486DX
P4S - Intel 486DX SL enhanced
P24 - Intel 486DX2
P24S - Intel 486DX2 SL enhanced
P24C - Intel 486DX4 SL enhanced low voltage
P24D - Intel 486DX2 write-back enhanced SL enhanced
     &EW
          &E: SL enhanced
           W: write-back enhanced

IBM 486DX - 5v SMM
IBM 486DXV - low voltage SMM
IBM 486DX2 - 5v SMM
IBM 486DX2V - low voltage SMM
IBM 486DX4W - low voltage write-back enhanced SMM
IBM 5x86C - low voltage write-back enhanced SMM

AMD 486DX2 - low voltage (no SMM)
AMD 486DX2W - low voltage write-back enhanced SMM
AMD 486DX4 - low voltage (no SMM)
AMD 486DX4W - low voltage write-back enhanced SMM
AMD 5x86 - low voltage write-back enhanced SMM
     SV8B:
          S: SMM; N: standard
          V: low power; _: standard
          8: 8Kbyte L1 cache
          B: write-back cache; T: write-through cache

SGS 486DX - 5v SMM
SGS 486DX2 - 5v SMM
SGS 486DX2V - low voltage SMM
SGS 5x86 - low voltage write-back enhanced SMM

Cyrix 5x86 - low voltage write-back enhanced SMM

W - Write-Back enhanced
V - Low voltage
Many of the IBM, Cyrix, and Texas Instruments 486 chips share similar pinouts.
The UMC U5D and U5S are clones of the Intel 486DX and 486SX, and share the same pinouts.

Created by: Chris Hare
See http://www.pchardwarelinks.com/486pin.htm for pin layout and descriptions.
Last edited: March 2, 2001