In the 1980s, if you wanted your computer to do floating-point calculations faster, you could buy the Intel 8087 floating-point coprocessor chip. Plugging it into your IBM PC would make operations up to 100 times faster, a big boost for spreadsheets and other number-crunching applications. The 8087...

   Early microprocessors were very slow when operating with floating-point numbers. But in 1980, Intel introduced the 8087 floating-point coprocessor, performing floating-point operations up to 100 times faster. This was a huge benefit for IBM PC applications such as AutoCAD, spreadsheets, and flight...

   I’ve been studying the standard cell circuitry in the Intel 386 processor recently. The 386, introduced in 1985, was Intel’s most complex processor at the time, containing 285,000 transistors. Intel’s existing design techniques couldn’t handle this complexity and the chip began to fall behind...

   pre background: #f4f4f4; border: 1px solid #ddd; border-left: 3px solid #a03; border-radius: 2px; color: #666; display: block; font-family: monospace; line-height: 1.3; margin-bottom: 1.6em; max-width: 60em; overflow: auto; padding: 1em 1.5em; page-break-inside: avoid; white-space: pre-wrap; word...

   The noted Diné (Navajo) weaver Marilou Schultz recently completed an intricate weaving composed of thick white lines on a black background, punctuated with reddish-orange diamonds. Although this striking rug may appear abstract, it shows the internal circuitry of a tiny silicon chip known as the...

   I was reading the latest issue of the journal Science, and a paper mentioned the compound Cr2Gr2Te6. For a moment, I thought my knowledge of the periodic table was slipping, since I couldn’t remember the element Gr. It turns out that Gr was supposed to be Ge, germanium, but that raises two issues....

   I’ve been reverse-engineering the Intel 386 processor (from 1985), and I’ve come across some interesting circuits for the chip’s input output (I O) pins. Since these pins communicate with the outside world, they face special dangers: static electricity and latchup can destroy the chip, while...

   Intel released the 386 processor in 1985, the first 32-bit chip in the x86 line. This chip was packaged in a ceramic square with 132 gold-plated pins protruding from the underside, fitting into a socket on the motherboard. While this package may seem boring, a lot more is going on inside it than...

   Have you ever wanted to reverse engineer an analog chip from a die photo? Wanted to understand what’s inside the black box of an integrated circuit? In this article, I explain my reverse engineering process, using the Philips TDA7000 FM radio receiver chip as an example. This chip was the first FM...

   Back in 2021, a collector friend of ours was visiting a dusty warehouse in search of Apollo-era communications equipment. A box with NASA-style lights caught his eye-the AGC Confirm light suggested a connection with the Apollo Guidance Computer. Disappointingly, the box was just an empty chassis...

   During the Apollo flights to the Moon, the astronauts observed the spacecraft’s orientation on a special instrument called the FDAI (Flight Director Attitude Indicator). This instrument showed the spacecraft’s attitude-its orientation-by rotating a ball. This ball was nicknamed the 8-ball because...

   In 1985, Intel introduced the groundbreaking 386 processor, the first 32-bit processor in the x86 architecture. To improve performance, the 386 has a 16-byte instruction prefetch queue. The purpose of the prefetch queue is to fetch instructions from memory before they are needed, so the processor...

   The groundbreaking Intel 386 processor (1985) was the first 32-bit processor in the x86 architecture. Like most processors, the 386 contains numerous registers; registers are a key part of a processor because they provide storage that is much faster than main memory. The register set of the 386...

   code font-size: 100%; font-family: courier, fixed; mult3 In 1977, Commodore released the PET computer, a quirky home computer that combined the processor, a tiny keyboard, a cassette drive for storage, and a trapezoidal screen in a metal unit. The Commodore PET, the Apple II, and Radio Shack’s TRS...

   Most people think of machine instructions as the fundamental steps that a computer performs. However, many processors have another layer of software underneath: microcode. With microcode, instead of building the processor’s control circuitry from complex logic gates, the control logic is...

   In the early 1960s, Douglas Engelbart started investigating how computers could augment human intelligence: If, in your office, you as an intellectual worker were supplied with a computer display backed up by a computer that was alive for you all day and was instantly responsive to every action you...

   This article is available in German at Heise Online. In 1993, Intel released the high-performance Pentium processor, the start of the long-running Pentium line. I’ve been examining the Pentium’s circuitry in detail and I came across a circuit to multiply by three, a complex circuit with thousands...

   What is the origin of the word mainframe , referring to a large, complex computer? Most sources agree that the term is related to the frames that held early computers, but the details are vague.1 It turns out that the history is more interesting and complicated than you’d expect. Based on my...

   Intel released the powerful Pentium processor in 1993, establishing a long-running brand of processors. Earlier, I wrote about the ROM in the Pentium’s floating point unit that holds constants such as π. In this post, I’ll look at some interesting circuits associated with this ROM. In particular...

   Addition is harder than you’d expect, at least for a computer. Computers use multiple types of adder circuits with different tradeoffs of size versus speed. In this article, I reverse-engineer an 8-bit adder in the Pentium’s floating point unit. This adder turns out to be a carry-lookahead adder,...

   The cargo cult metaphor is commonly used by programmers. This metaphor was popularized by Richard Feynman’s cargo cult science talk with a vivid description of South Seas cargo cults. However, this metaphor has three major problems. First, the pop-culture depiction of cargo cults is inaccurate and...

   Intel released the powerful Pentium processor in 1993, establishing a long-running brand of high-performance processors.1 The Pentium includes a floating-point unit that can rapidly compute functions such as sines, cosines, logarithms, and exponentials. But how does the Pentium compute these...

   In 1993, Intel released the high-performance Pentium processor, the start of the long-running Pentium line. The Pentium had many improvements over the previous processor, the Intel 486, including a faster floating-point division algorithm. A year later, Professor Nicely, a number theory professor,...

   I was studying the silicon die of the Pentium processor and noticed some puzzling structures where signal lines were connected to the silicon substrate for no apparent reason. Two examples are in the photo below, where the metal wiring (orange) connects to small square regions of doped silicon ...

   Forbes recently published the Forbes 400 List for 2024, listing the 400 richest people in the United States. This inspired me to make a histogram to show the distribution of wealth in the United States. It turns out that if you put Elon Musk on the graph, almost the entire US population is crammed...