Intel released the powerful Pentium processor in , 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 pi;. 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 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...

   Intel released the powerful Pentium processor in , establishing a long running brand of high performance processors. 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 , 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 , 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 List for , listing the 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...

   We recently received an attitude indicator for the F fighter plane, an instrument that uses a rotating ball to show the aircraft’s orientation and direction. In a normal aircraft, the artificial horizon shows the orientation in two axes pitch and roll , but the F indicator uses a rotating ball...

   Ferroelectric memory FRAM is an interesting storage technique that stores bits in a special ferroelectric material. Ferroelectric memory is nonvolatile like flash memory, able to hold its data for decades. But, unlike flash, ferroelectric memory can write data rapidly. Moreover, FRAM is much...

   Hurrying through the National Gallery of Art five minutes before closing, I passed a Navajo weaving with a complex abstract pattern. Suddenly, I realized the pattern was strangely familiar, so I stopped and looked closely. The design turned out to be an image of Intel’s Pentium chip, the start of...

   The Minuteman missile was introduced in as a key part of America’s nuclear deterrent. The Minuteman III missile is currently the only US land based intercontinental ballistic missile ICBM , with missiles ready for launch, spread across five central states. The missile contains a...

   The Space Shuttle contained a bulky printer so the astronauts could receive procedures, mission plans, weather reports, crew activity plans, and other documents. Needed for the first Shuttle launch in , this printer was designed in just months, built around an Army communications terminal....

   In this article, I look inside a chip in the IBM Control Unit. But before I discuss the chip, I need to give some background on mainframes. I didn’t completely analyze the chip, so don’t expect a nice narrative or solid conclusions. Die photo of the Motorola IBM SC chip. Click this...

   Intel released the powerful Pentium processor in , a chip to separate the really power hungry folks from ordinary mortals. The original Pentium was followed by the Pentium Pro, the Pentium II, and others, spawning a long running brand of high performance processors, Intel’s flagship line...

   To use the Montreal subway the Métro , you tap a paper ticket against the turnstile and it opens. The ticket works through a system called NFC, but what’s happening internally How does the ticket work without a battery How does it communicate with the turnstile And how can it be so cheap that...

   I recently obtained an aerospace computer from the early s, apparently part of a navigation system. Aerospace computers are an interesting but mostly neglected area of computer hardware, so I’m always delighted to examine one up close. In an era when most computers were large mainframes,...

   In , Intel introduced the microprocessor, a variant of the bit processor. IBM’s decision to use the processor in the IBM PC was a critical point in computer history, leading to the success of the x architecture. The designers of the IBM PC selected the for...

   When I look inside a chip from the popular series, I know what to expect: a fairly simple die, implemented in a straightforward, cost effective way. However, when I looked inside a military grade chip built by Integrated Device Technology IDT I found a very unexpected layout: over ...

   In , Intel introduced the microprocessor, a variant of the bit processor. IBM’s decision to use the processor in the IBM PC was a critical point in computer history, leading to the dominance of the x architecture that continues to the present. One way that the ...

   What would you say is the first microcomputer The Apple I from The Altair from Perhaps the lesser known Micral N or Q How about the Arma Micro Computer from way back in . The Arma Micro Computer was a compact pound transistorized computer, designed for...

   The Bendix Central Air Data Computer CADC is an electromechanical analog computer that uses gears and cams for its mathematics. It was a key part of military planes such as the F and the F fighters, computing airspeed, Mach number, and other air data . The rotating gears are powered by...

   MathJax tex: inlineMath: ’ ’, ’ ’ , ’ ’, ’ ’ , svg: fontCache: ’global’ , chtml: displayAlign: ’left’ ; MathJax.Hub.Config HTML CSS : scale: ; .MathJax font size: em important In the s, many fighter planes used the ...

   The processor was Intel’s most complex processor at the time, with , transistors. Intel had scheduled person years to design the processor, but it was falling behind schedule. The design team decided to automate chunks of the layout, developing automatic place and route ...

   I recently came across an interesting die photo of a Soviet chip, probably designed in the s. This article provides an introductory guide to reverse engineering CMOS circuits, using this chip as an example. Although the chip looks like a tangle of lines at first, its large features and simple...

   MathJax tex: inlineMath: ’ ’, ’ ’ , ’ ’, ’ ’ , svg: fontCache: ’global’ , chtml: displayAlign: ’left’ ; MathJax.Hub.Config HTML CSS : scale: ; .MathJax font size: em important The Bendix Central Air Data Computer CADC ...