Content for Reverse Engineering

Reverse-engineering the standard-cell logic inside a vintage IBM chip

“Integrated circuits are often built from standard-cell logic, constructed from standardized building blocks such as NAND gates. Since I’ve been looking at a chip that uses standard-cell logic, I figured it was a good opportunity to examine standard-cell logic …

Teardown of a quartz crystal oscillator and the tiny IC inside

“The quartz oscillator is an important electronic circuit, providing highly-accurate timing signals at a low cost. A quartz crystal has the special property of piezoelectricity, changing its electrical properties as it vibrates. Since a crystal can be cut to vibrate …

Reverse-engineering a low-power LED flasher chip

“How do you make an LED blink? A vintage way is the LM3909, a chip from 1975 that can flash an LED for a year from a single flashlight battery. This chip has some surprising features, such as a charge …

Reverse-engineering an early calculator chip with four-phase logic

“In 1969, high-density MOS integrated circuits were still new and logic circuits were constructed in a variety of ways. One technique was “four-phase logic”, which provided ten times the speed and density of standard logic gates while using 1/10 …

Reverse-engineering the clock chip in the first MOS calculator

“In 1969, Sharp introduced the first calculator built from high-density MOS chips, the QT-8D, followed by the handheld Sharp EL-8, the world’s smallest calculator at the time.1 These calculators were high-end products, selling for $345 (about …

Reverse engineering RAM storage in early Texas Instruments calculator chips

“Texas Instruments introduced the first commercial single-chip computer in 1974, combining the CPU, RAM, ROM, and I/O into one chip. This family of 4-bit processors was called the TMS1000.1 A 4-bit processor now seems very limited, but it …

Reverse-engineering the classic MK4116 16-kilobit DRAM chip

“Back in the late 1970s, the most popular memory chip was Mostek’s MK4116, holding a whopping (for the time) 16 kilobits. It provided storage for computers such as the Apple II, TRS-80, ZX Spectrum, Commodore PET, IBM PC …

Reverse-engineering the carry-lookahead circuit in the Intel 8008 processor

“The 8008 was Intel’s first 8-bit microprocessor, introduced in 1972. While primitive by today’s standards, the 8008 is historically important because it essentially started the microprocessor revolution and is the ancestor of the modern x86 processor family. I …

Inside the stacked RAM modules used in the Apple III

“In 1978, a memory chip stored just 16 kilobits of data. To make a 32-kilobit memory chip, Mostek came up with the idea of putting two 16K chips onto a carrier the size of a standard integrated circuit, creating the …

Learning to Decapsulate Integrated Circuits using Acid Deposition

“I’ve been looking to try my hand at IC decapsulation for years, and finally got the time to do it. The process took plenty of trial and error, so this post will document most of my failures and successes …