The Pentium die has a lot of initials from the designers,...

The Pentium die has a lot of initials from the designers, in various shapes and sizes. These photos show a subset of the initials. Intel removed the initials from the next revision (80502).
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A closeup of the die showing dozens of initials between two bond wires.

Initials of various sizes next to some circuitry. The initials are arranged vertically. Some are either a pair of initials or four letters, it's unclear. E.g. ZBGK. There is a three-letter initial: YBM

Initials formed by vias. The vias between two metal layers are arranged to make letters as a grid of dots.

Small and large initials arranged vertically and horizontally.

Like 5 August at 18:47 | Open on oldbytes.space

4 comments

Ken Shirriff

I made this diagram to show the different functional blocks on the Pentium P5 die.
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The Pentium die with functional blocks labeled. The code cache and data cache are large blocks on the left. The integer datapath (the superscalar integer execution unit) is a vertical rectangle in the middle. The floating point unit is a vertical rectangle next to it. Instruction fetch and instruction decode are at the top, with branch prediction logic nearby along with the microcode ROM.

5 August at 18:50 | Open on oldbytes.space

Tommy Thorn

@kenshirriff The Bus Interface Logic block seems shockingly large, half the area of either cache. What's going on?

5 August at 18:59 | Open on chaos.social

Ken Shirriff

@tommythorn In comparison, on the 8086, the Bus Interface Unit is roughly half the chip. The Bus Interface is doing a lot: performing prefetches, handling memory and I/O bus cycles, handling interrupts, bus hold, bus locking, cache operations, and so forth.

5 August at 19:05 | Open on oldbytes.space

Ryan Finnie

@kenshirriff TIL Zaphod Beeblebrox was a chip designer. Explains why he went on to put his initials onto his own brain.

5 August at 18:56 | Open on fosstodon.org

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