The Soviet space program used completely different controls and instruments from American spacecraft. One of the most interesting navigati... | Continue reading
How can you find out what's inside a sealed electronics module from the 1960s? In this blog post, I reverse-engineer a hybrid flip flop mo... | Continue reading
How did NASA communicate with the Apollo astronauts, hundreds of thousands of miles from Earth? The premodulation processor 1 (below) was... | Continue reading
How did NASA communicate with the Apollo astronauts, hundreds of thousands of miles from Earth? The premodulation processor 1 (below) was... | Continue reading
In this blog post, I reverse-engineer a hybrid module that was used for ground-testing of equipment from the Apollo space program. But fir... | Continue reading
During the Apollo missions to the Moon, a critical task for NASA was determining the spacecraft's position. To accomplish this, they devel... | Continue reading
Apple's first product was the Apple-1 computer, introduced exactly 46 years ago, on April 11, 1976. This early microcomputer used an unus... | Continue reading
Many circuits, such as a computer power supply or a phone charger, require a stable voltage reference, but it's harder than you might expec... | Continue reading
The recent arc3 release of Arc includes news.arc , the Arc source code for the Hacker News forum . Examining this code can give some insig... | Continue reading
The IBM 1401 team at the Computer History Museum accumulates a lot of mystery components from donations and other sources. While going thr... | Continue reading
Have you ever wondered what's inside your Macbook's charger? There's a lot more circuitry crammed into the compact power adapter than you... | Continue reading
Apple's first product was the Apple-1 computer, introduced in 1976. This early microcomputer used an unusual type of storage for its disp... | Continue reading
How hard could it be to fix a vintage solderless breadboard that doesn't quite work? The "elite 2 circuit design test system" below combin... | Continue reading
The revolutionary Polaroid SX-70 1 camera (1972) was a marvel of engineering: the world's first instant SLR camera. This iconic camera wa... | Continue reading
The Yamaha DX7 digital synthesizer (1983) was the classic synthesizer in 1980s pop music. It uses a technique called FM synthesis to produ... | Continue reading
The Yamaha DX7 digital synthesizer (1983) was the classic synthesizer in 1980s pop music. It uses a technique called FM synthesis to produ... | Continue reading
Every Bitcoin transaction is stored in the distributed database known as the Bitcoin blockchain. However, people have found ways to hack ... | Continue reading
In 1962, the Simpson's department store in Toronto used an IBM computer to help customers select Christmas gifts, based on the characteris... | Continue reading
For the holidays, I decapped a chip that plays three Christmas melodies. The UM66T melody chip from the 1980s was designed for application... | Continue reading
The Yamaha DX7 digital synthesizer (1983) was the classic synthesizer in 1980s pop music. It uses two custom digital chips to generate sou... | Continue reading
The Yamaha DX7 digital synthesizer (1983) was the classic synthesizer for 1980s pop music. It used two custom digital chips to generate so... | Continue reading
The Yamaha DX7 digital synthesizer was released in 1983 and became extremely popular, defining the sound of 1980s pop music. Because micro... | Continue reading
The Yamaha DX7 digital synthesizer was released in 1983 and became "one of the most important advances in the history of modern popular mu... | Continue reading
The vintage IBM circuit board below has a large metal block on it that caught my attention, so I investigated it in detail. It turns out t... | Continue reading
The new biography Steve Jobs contains a remarkable claim about the power supply of the Apple II and its designer Rod Holt: [1] Instead o... | Continue reading
I recently did a PC power supply teardown so I figured it would be interesting to go deeper and see what happens inside the power supply'... | Continue reading
The revolutionary Intel 8008 microprocessor is 45 years old today (March 13, 2017), so I figured it's time for a blog post on reverse-engine... | Continue reading
A computer's arithmetic-logic unit (ALU) is the heart of the processor, performing arithmetic and logic operations on data. If you've studie... | Continue reading
How did the Apollo astronauts communicate on their trip to the Moon, 240,000 miles back to Earth? They used a 32-pound amplifier, built ar... | Continue reading
In the early 1960s, General Electric developed a technology called thin-film electronics. 1 These circuits were built from thin films of ... | Continue reading
The Arduino language lets you program microcontrollers at a high level, controlling I/O pins without worry about exactly how the micro... | Continue reading
The Arduino language lets you program microcontrollers at a high level, controlling I/O pins without worry about exactly how the micro... | Continue reading
One of the under-appreciated aspects of the Apollo launches to the Moon is how much testing was required. I recently came across an item t... | Continue reading
One of the under-appreciated aspects of the Apollo launches to the Moon is how much testing was required. I recently came across an item t... | Continue reading
Have you ever wanted to take a bunch of photos of an integrated circuit die and combine them into a high-res image? The stitching software... | Continue reading
Have you ever wondered what's inside your computer's power supply? The task of a PC power supply is to convert the power from the wall (1... | Continue reading
Recently, I received a die photo of a mystery integrated circuit, the OQ100, 1 from EvilMonkeyDesignz . I analyzed the die photo and foun... | Continue reading
I recently saw an interesting die photo of an unknown chip on Twitter , so I did some analysis of it. Looking at the circuitry inside, the... | Continue reading
In 1971, semiconductor memory was still a new development so chips couldn't hold a lot of data. To double the storage capacity, IBM used... | Continue reading
I've been studying the guidance computer from a Titan II nuclear missile. This compact computer was used in the 1970s to guide a Titan II ... | Continue reading
Integrated circuits are often built from standard-cell logic, constructed from standardized building blocks such as NAND gates. Since I've... | Continue reading
How did computers implement logic gates in the 1950s? Computers were moving into the transistor age, but transistors were expensive so cir... | Continue reading
IBM used some unusual techniques in its integrated circuits, and one of the most visible is packaging them in square metal cans. I've been... | Continue reading
The photo below of a "woman wiring an early IBM computer" has appeared on Twitter a bunch of times , and it stoked my curiosity: what was ... | Continue reading
How do you boot a computer from punch cards when the computer has no operating system and no ROM? To make things worse, this computer req... | Continue reading
The quartz oscillator is an important electronic circuit, providing highly-accurate timing signals at a low cost. A quartz crystal has the... | Continue reading