Ken Shirriff on Nostr: The chip I photographed is the i486 SX, which is the version of the 486 without a ...

The chip I photographed is the i486 SX, which is the version of the 486 without a floating point unit. But you can see from the photo that it has a floating point unit on the die. It's unclear if Intel deliberately disabled the floating point unit to segment the market between the low-end SX and the high-end DX, or if chips with an FPU fault were sold as the SX.