Ken Shirriff

Reverse engineer and computer historian who deconstructs vintage processors, power supplies, and space hardware down to the silicon. His blog posts explain how historical chips actually worked at the transistor level, with original die photography and analysis.

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Recent Articles

Microcode in Intel's 8087 floating-point chip: the scale instruction
Ken Shirriff · Tech · 8d ago
Cores in space: The core memory module from a 1980 Spacelab computer
Ken Shirriff · Tech · 21d ago
Energizing a vacuum-tube flip-flop module from a 1948 IBM system
Ken Shirriff · Tech · 1mo ago
Examining circuit boards from the Space Shuttle's I/O Processor
Ken Shirriff · Tech · 2mo ago
The adder at the heart of Intel's 8087 floating-point chip
Ken Shirriff · Tech · 3mo ago
Powering up a module from the IBM 604: an electronic calculator from 1948
Ken Shirriff · Tech · 3mo ago
Microcode inside the Intel 8087 floating-point chip: register exchange
Ken Shirriff · Tech · 3mo ago
Reverse engineering circuitry in a Spacelab computer from 1980
Ken Shirriff · Tech · 4mo ago
The electromechanical angle computer inside the B-52 bomber's star tracker
Ken Shirriff · Tech · 5mo ago
The rise and fall of IBM's 4 Pi aerospace computers: an illustrated history
Ken Shirriff · Tech · 5mo ago
Instruction decoding in the Intel 8087 floating-point chip
Ken Shirriff · Tech · 7mo ago
Notes on the Intel 8086 processor's arithmetic-logic unit
Ken Shirriff · Tech · 8mo ago
Conditions in the Intel 8087 floating-point chip's microcode
Ken Shirriff · Tech · 8mo ago
The stack circuitry of the Intel 8087 floating point chip, reverse-engineered
Ken Shirriff · Tech · 9mo ago
Unusual circuits in the Intel 386's standard cell logic
Ken Shirriff · Tech · 10mo ago
A Navajo weaving of an integrated circuit: the 555 timer
Ken Shirriff · Tech · 12mo ago
Why do people keep writing about the imaginary compound Cr2Gr2Te6?
Ken Shirriff · Tech · 13mo ago
Here be dragons: Preventing static damage, latchup, and metastability in the 386
Ken Shirriff · Tech · 13mo ago
A CT scanner reveals surprises inside the 386 processor's ceramic package
Ken Shirriff · Tech · 13mo ago
How to reverse engineer an analog chip: the TDA7000 FM radio receiver
Ken Shirriff · Tech · 13mo ago