Sometimes it's easier to identify an IC with a microscope. While sorting a box of old ICs, CuriousMarc came across some Harris ICs labeled "F1-10-5", a mysterious part number that didn't show up in any databooks. Since unidentifiable ICs are useless, he gave me one to analyze. Conveniently, it was in a ceramic package, so I could open it up with a quick tap from a chisel. Under the microscope, the

I hope you're not tired of the 8087, because I have another article about Intel's floating-point chip. 1 In 1980, Intel introduced the 8087, making floating-point operations much faster in the IBM PC and other systems. In this article, I look at the algorithm behind the chip's tangent instruction. One popular approach for trigonometric functions is an algorithm called CORDIC. Another approach is a

In the 1970s, floating-point arithmetic was a mess. Computer manufacturers had a dozen incompatible arithmetic standards. Moreover, floating-point systems were designed around hardware simplicity rather than mathematical rigor, leading to problems with numerical stability. This changed when Intel introduced the 8087 floating-point coprocessor chip in 1980, designed to be as accurate as possible, e

Spacelab was a reusable laboratory that could be carried in the Space Shuttle's cargo bay, providing lab space for astronauts and experiments. 1 Because Spacelab was a European project, it used a French-built minicomputer, the Mitra 125 MS, 2 rather than the Shuttle's main computers, IBM-built AP-101 systems. For storage, the Spacelab computer contained 128 kilobytes of RAM. Rather than silicon me

In 1948, IBM introduced the 604 Electronic Calculating Punch. This machine was a programmable calculator, about the size of a double refrigerator. It was not quite a computer, but was programmed by plugging wires into a plugboard. This machine read numbers from a punch card, performed up to 60 calculations on these numbers, and then recorded the results by punching holes in the card. 1 It processe

The Space Shuttle's five 1 general-purpose computers played a critical role in each flight: controlling the engines, monitoring thousands of sensors, displaying data to the astronauts, and navigating the Shuttle. Each computer consisted of two 60-pound aluminum-alloy boxes: the box on the right is the CPU, a 32-bit processor that executed 420,000 instructions per second. These computers were desig

In 1980, Intel released the Intel 8087 floating-point coprocessor, a chip that could make math up to 100 times faster. As well as arithmetic and square roots, the 8087 computed transcendental functions including tangent, exponentiation, and logarithms. But it all depended on a 69-bit adder: "The arithmetic heart of the floating-point execution unit is centered about a nanomachine comprised of the

1948 was an interesting time for computing. For decades, businesses had used punch card equipment that added and sorted electromechanically. Now these electromechanical relays and counting wheels were being used to build room-filling general-purpose computers such as Harvard Mark I (1944) and IBM's SSEC (1948). But slow electromechanical mechanisms were already becoming obsolete. World War II had

In 1980, Intel introduced the 8087 floating-point chip, a co-processor that made floating-point operations up to 100 times faster. This chip was highly influential, and today most processors use the floating-point standard introduced by the 8087. The 8087 uses complicated algorithms to accurately compute functions such as square roots, tangents, and exponentials. These algorithms are implemented i

Spacelab was a reusable laboratory that could be carried in the cargo bay of the Space Shuttle, providing lab space for astronauts and experiments. Spacelab was controlled by a French-built minicomputer, called the Mitra 125 MS . Unlike modern computers, this computer didn't contain a microprocessor chip. Instead, its 16-bit processor was constructed from several boards of chips. In this article,

Before GPS, how did aircraft navigate? One important technique was celestial navigation: navigating from the positions of the stars, planets, or the sun. While celestial navigation is accurate, cannot be jammed, and doesn't require any broadcast infrastructure, it is a difficult and time-consuming process to perform manually. In the early 1960s, an automated system was developed for the B-52 bombe

The morning of April 12, 1981, 20 years to the day after Yuri Gagarin became the first person in space, the Space Shuttle thundered into the Florida sky. Commander Young and Pilot Crippen were at the controls as the Shuttle ascended on its first flight. But the launch, like much of the flight, was really under the control of four computers in the avionics bays one deck below the crew. A fifth comp

In the 1980s, if you wanted your IBM PC to run faster, you could buy the Intel 8087 floating-point coprocessor chip. With this chip, CAD software, spreadsheets, flight simulators, and other programs were much speedier. The 8087 chip could add, subtract, multiply, and divide, of course, but it could also compute transcendental functions such as tangent and logarithms, as well as provide constants s

In 1978, Intel introduced the 8086 processor, a revolutionary chip that led to the modern x86 architecture. Unlike modern 64-bit processors, however, the 8086 is a 16-bit chip. Its arithmetic/logic unit (ALU) operates on 16-bit values, performing arithmetic operations such as addition and subtraction, as well as logic operations including bitwise AND, OR, and XOR. The 8086's ALU is a complicated p

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 uses complicated algorithms to compute trigonometric, logarithmic, and exponential functions. These

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 simulators. The 8087 was so effective that today's computers still use a floating-point system based

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 schedule. To meet the schedule, the 386 team started using a technique called standard cell logic. Instead

The New York Times recently introduced a new daily puzzle called Pips . You place a set of dominoes on a grid, satisfying various conditions. For instance, in the puzzle below, the pips (dots) in the purple squares must sum to 8, there must be fewer than 5 pips in the red square, and the pips in the three green squares must be equal. (It doesn't take much thought to solve this "easy" puzzle, but t

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 555 timer. This chip has hundreds of applications in everything from a sound generator to a windshield

I was reading the latest issue of the journal Science , and a paper mentioned the compound Cr 2 Gr 2 Te 6 . 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. First, shouldn't the peer reviewers and proofreaders at a top journal catch this error? But m