Examining a vintage RAM chip, I find a counterfeit with an entirely different die inside

Ken Shirriff writes, “A die photo of a vintage 64-bit TTL RAM chip came up on Twitter recently, but the more I examined the photo the more puzzled I became. The chip didn’t look at all like a RAM chip or even a TTL chip, and in fact appeared partially analog. By studying the chip’s […]

A look inside the DS3231 real-time clock

Pete posted an article taking a closer look at Maxim’s DS3231 real-time clock: Fortunately, Maxim also offers the DS3231, which is advertised as an “Extremely Accurate I2C-Integrated RTC/TCXO/Crystal”. This chip has the 32kHz crystal integrated into the package itself and uses a built-in temperature sensor to periodically measure the temperature of the crystal and, by […]

Inside Intel’s first product: the 3101 RAM chip held just 64 bits

Ken Shirriff writes: Intel’s first product was not a processor, but a memory chip: the 31011 RAM chip, released in April 1969. This chip held just 64 bits of data (equivalent to 8 letters or 16 digits) and had the steep price tag of $99.50.2 The chip’s capacity was way too small to replace core […]

Reverse engineering the 76477 “Space Invaders” sound effect chip from die photos

Ken Shirriff has written an article on reverse engineering the 76477 “Space Invaders” sound effect chip: Remember the old video game Space Invaders? Some of its sound effects were provided by a chip called the 76477 Complex Sound Generation chip. While the sound effects1 produced by this 1978 chip seem primitive today, it was used […]

Inside the vintage 74181 ALU chip: how it works and why it’s so strange

Ken Shirriff writes: The 74181 ALU (arithmetic/logic unit) chip powered many of the minicomputers of the 1970s: it provided fast 4-bit arithmetic and logic functions, and could be combined to handle larger words, making it a key part of many CPUs. But if you look at the chip more closely, there are a few mysteries. […]

Analyzing the vintage 8008 processor from die photos: its unusual counters

Ken Shirriff writes: 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-engineering its internal circuits. One of the interesting things about old computers is how they implemented things in unexpected ways, and the 8008 is no exception. Compared to modern […]

Reverse-engineering the surprisingly advanced ALU of the 8008 microprocessor

Ken Shirriff has written an article on reverse engineering the ALU of the 8008 microprocessor: A computer’s arithmetic-logic unit (ALU) is the heart of the processor, performing arithmetic and logic operations on data. If you’ve studied digital logic, you’ve probably learned how to combine simple binary adder circuits to build an ALU. However, the 8008’s […]

Inside the 74181 ALU chip: die photos and reverse engineering

A detailed die photos and reverse engineering of the 74181 ALU chip by Ken Shirriff: What’s inside a TTL chip? To find out, I opened up a 74181 ALU chip, took high-resolution die photos, and reverse-engineered the chip.1 Inside I found several types of gates, implemented with interesting circuitry and unusual transistors. The 74181 was a […]

Die photos and analysis of the revolutionary 8008 microprocessor, 45 years old

Ken Shirriff has written an article detailing die photos of the vintage Intel 8008 that reveal the circuitry it used: Intel’s groundbreaking 8008 microprocessor was first produced 45 years ago.1 This chip, Intel’s first 8-bit microprocessor, is the ancestor of the x86 processor family that you may be using right now. I couldn’t find good […]

Inside a RFID race timing chip: die photos of the Monza R6

Ken Shirriff took some die photos of the Monza R6 chip  and wrote a post on his blog on how the RFID timing chip works: I recently watched a cross-country running race that used a digital timing system, so I investigated how the RFID timing chip works. Each runner wears a race bib like the […]

Reverse engineering a server CPU voltage regulator module

Andy Brown wrote an article on reverse engineering a CPU voltage regulator: A recent ebay fishing expedition yielded an interesting little part for the very reasonable sum of about five pounds. It’s a voltage regulator module from a Dell PowerEdge 6650 Xeon server. I originally bought this because I had the idea of salvaging parts […]

Reverse engineering a simple four function calculator: die decap

Electronupdate did a teardown and analysis of a cheap four function calculator: It’s such an amazingly old looking die Even with 400x magnification it would not be too hard to reverse engineer back to a schematic! This must be a very old design indeed. When one thinks of high-tech it’s always the new-new thing… however […]

Reverse engineering the popular 555 timer chip (CMOS version)

Ken Shirriff wrote an article on reverse engineering a 555 timer chip,  He writes: This article explains how the LMC555 timer chip works, from the tiny transistors and resistors on the silicon chip, to the functional units such as comparators and current mirrors that make it work. The popular 555 timer integrated circuit is said to be […]

Nevo C2 remote control – Reverse engineering, part 1

Reverse engineering of a Nevo C2 remote control from Arantius.com Most recently I’ve switched to the “Nevo C2” remotes (also known as “Xsight Color” or “ARRX15G”), which have a graphical display built in. This makes it easy for me to deal with the huge array (TiVo, HTPC, plus eleven game consoles) of devices I’ve got hooked […]

555 timer teardown: Inside the world’s most popular IC

Another great teardown article by Ken Shirriff, a look inside the 555 timer chip: Given the popularity of the 555 timer, I thought it would be interesting to find out what’s inside the 555 timer and how it works. While the 555 timer is usually sold as a black plastic IC, it is also available […]

More ARM1 processor reverse engineering: the priority encoder

In a previous post, Ken Shirriff reverse engineered the silicon in the ARM1 processor, this time he reverse-engineer the priority encoder in the ARM1 processor: In this article, I reverse-engineer the priority encoder in the ARM1 processor. By examining the chip layout provided by the Visual ARM1 project, I have determined how this circuit works […]

Counting bits in hardware: Reverse engineering the silicon in the ARM1 processor

Ken Shirriff writes: How can you count bits in hardware? In this article, I reverse-engineer the circuit used by the ARM1 processor to count the number of set bits in a 16-bit field, showing how individual transistors form multiplexers, which are combined into adders, and finally form the bit counter. The ARM1 is the ancestor […]

Reverse engineering the ARM1, ancestor of the iPhone’s processor

Another great article from Ken Shirriff, this time on reverse engineering the ARM1: Almost every smartphone uses a processor based on the ARM1 chip created in 1985. The Visual ARM1 simulator shows what happens inside the ARM1 chip as it runs; the result (below) is fascinating but mysterious.[1] In this article, I reverse engineer key […]

Reverse engineering the ESP8266 WIFI-to-Serial port adapter

Here’s a video from electronupdate on reverse engineering the ESP8266 WIFI-to-Serial port adapter: Another very interesting bit of technology. The combination of so much functionality into such a small part is a real touch-stone as to where things are heading. A quick look at the antenna design to see if I could sort down the […]