Ken Shirriff on Nostr: Here's a closeup of the adder and associated circuitry. The 8-bit adder is marked in ...

Here's a closeup of the adder and associated circuitry. The 8-bit adder is marked in red. The circuitry below helps test the chip; the Pentium includes a lot of circuitry just for testing. In this photo, I removed all 3 metal layers, showing the polysilicon and doped silicon forming transistors. 2/n