- A bug fix in the 8086 microprocessor, revealed in the die’s silicon (righto.com)
The 8086 microprocessor was a groundbreaking processor introduced by Intel in 1978. It led to the x86 architecture that still dominates desktop and server computing. While reverse-engineering the 8086 from die photos, a particular circuit caught my eye because its physical layout on the die didn’t match the surrounding circuitry. This circuit turns out to implement special functionality for a couple of instructions, subtlely changing the way they interacted with interrupts. Some web searching revealed that this behavior was changed by Intel in 1978 to fix a problem with early versions of the 8086 chip. By studying the die, we can get an idea of how Intel dealt with bugs in the 8086 microprocessor.
- Gottfried Wilhelm Leibniz (Wikipedia)
Gottfried Wilhelm Leibniz (1 July 1646 [O.S. 21 June] – 14 November 1716) was a German polymath active as a mathematician, philosopher, scientist and diplomat who invented calculus in addition to many other branches of mathematics and statistics. Leibniz has been called the “last universal genius” due to his knowledge and skills in different fields and because such people became less common during the Industrial Revolution and spread of specialized labor after his lifetime. He is a prominent figure in both the history of philosophy and the history of mathematics. He wrote works on philosophy, theology, ethics, politics, law, history, philology, games, music, and other studies. Leibniz also made major contributions to physics and technology, and anticipated notions that surfaced much later in probability theory, biology, medicine, geology, psychology, linguistics and computer science. In addition, he contributed to the field of library science by devising a cataloguing system whilst working at the Herzog August Library in Wolfenbüttel, Germany, that would have served as a guide for many of Europe’s largest libraries. Leibniz’s contributions to a wide range of subjects were scattered in various learned journals, in tens of thousands of letters and in unpublished manuscripts. He wrote in several languages, primarily in Latin, French and German.