Evergreen REV TO 486 (286)

An uncommon upgrade chip for the 286! It upgrades a 286 to an IBM 486SLC2 that can run at 40, 50 or 66MHz with 16k L1-cache. In my case I think it'll run at 40MHz (it's clock doubled) since the FPU is rated at 20MHz. I have no documentation to verify, however.

Basically IBM upgraded their 386SLC 8KB L1 chip with 16KB L1-cache and the i486 instruction set to make a 486-class CPU on a 16-bit bus. Evergreen fitted that CPU on this little PCB along with a Cyrix FasMath FPU to create a beefy upgrade for your old system.