HP 27201A, the world’s first speech synthesizer by a major computer company

smbakeryt has written an article on reverse-engineering the protocol used by the HP 27201A: The HP 27201A is a TMS5220 based speech synthesizer released in 1983. According to the HP museum, it’s the first synthesizer designed by a major computer computer. Yes, the TI99/4A’s speech synthesizer uses the same IC and is at least contemporary […]

Reverse-engineering a low-power LED flasher chip

Ken writes, “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 pump that lets you power a 2-volt LED from a 1.5-volt battery. This […]

Reverse-engineering the classic MK4116 16-kilobit DRAM chip

Ken has written an article on 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, and Xerox Alto as […]

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

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’ve been studying the 8008’s silicon die under the […]

Reverse-engineering the first FPGA chip, the XC2064

Ken has written an article on reverse engineering the first FPGA chip, the XC2064: The FPGA was invented by Ross Freeman1 who co-founded Xilinx2 in 1984 and introduced the first FPGA, the XC2064. 3 This FPGA is much simpler than modern FPGAs—it contains just 64 logic blocks, compared to thousands or millions in modern FPGAs—but […]

Reverse-engineering and comparing two Game Boy audio amplifier chips

Reverse-engineering and comparing two game boy audio amplifier chips @ righto.com The Nintendo Game Boy contains an audio amplifier chip for sound through a speaker or headphones. In this post, I reverse-engineer this chip and compare it with the later Game Boy Color chip (reverse-engineered earlier). Unexpectedly the Game Boy Color uses an entirely different […]

Extracting ROM constants from the 8087 math coprocessor’s die

Ken posted an article taking a closer look at Intel 8087 chip: Intel introduced the 8087 chip in 1980 to improve floating-point performance on the 8086 and 8088 processors, and it was used with the original IBM PC. Since early microprocessors operated only on integers, arithmetic with floating-point numbers was slow and transcendental operations such […]

Tiny transformer inside: Decapping an isolated power transfer chip

Ken Shirriff writes: I saw an ad for a tiny chip1 that provides 5 volts2 of isolated power: You feed 5 volts in one side, and get 5 volts out the other side. What makes this remarkable is that the two sides can have up to 5000 volts between them. This chip contains a DC-DC […]

Deconstructing Sega’s System 16 security – part 2

Sega’s FD1089 security module reverse engineering part 2: The FD1089 module variants from Hitachi / SEGA were fabricated in a plastic case, on the back of the module a epoxy layer is visible together with two rows of pins arranged as DIP64. This arrangement mimics a standard 68000 CPU as intended by SEGA. The sample […]

A circuit board from the Saturn V rocket, reverse-engineered and explained

Ken Shirriff writes, “In the Apollo Moon missions, the Saturn V rocket was guided by an advanced onboard computer system built by IBM. This system was built from hybrid modules, similar to integrated circuits but containing individual components. I reverse-engineered a circuit board from this system and determined its function: Inside the computer’s I/O unit, […]

Repairing a vintage 40-kilovolt xenon lamp igniter

Ken Shirriff writes: What do xenon lamps and the invention of radio have in common? The box below is a 1960s German high voltage unit that CuriousMarc obtained as part of an auction. After some research, we determined that it is an Osram1 igniter2, which generates a 40-kilovolt pulse3 to ignite a xenon arc lamp. […]

Inside a Titan missile guidance computer

Ken Shirriff has written an excellent in-depth look at a Titan missile guidance computer: 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 nuclear missile towards its target or send a Titan IIIC rocket into the proper orbit. The […]

Looking inside a vintage Soviet TTL logic integrated circuit

Ken Shirriff examines a 1980s chip used in a Soyuz space clock: The clock is built from TTL integrated circuits, a type of digital logic that was popular in the 1970s through the 1990s because it was reliable, inexpensive, and easy to use. (If you’ve done hobbyist digital electronics, you probably know the 7400-series of […]

Inside the digital clock from a Soyuz spacecraft

Ken Shirriff has written an article on reverse engineering a “Onboard space clock” from a Soyuz mission: We recently obtained a clock that flew on a Soyuz space mission.1 The clock, manufactured in 1984, contains over 100 integrated circuits on ten circuit boards. Why is the clock so complicated? In this blog post, I examine […]

Op amp on the Moon: Reverse-engineering a hybrid op amp module

Ken Shirriff has written an article on reverse engineering a hybrid op amp module: I recently obtained a mysterious electronic component in a metal can, flatter and slightly larger than a typical integrated circuit.1 After opening it up and reverse engineering the circuit, I determined that this was an op amp built for NASA in […]

Two bits per transistor: high-density ROM in Intel’s 8087 floating point chip

Ken Shirriff has a great write-up about the multi-level ROM in Intel’s 8087 floating point chip: The 8087 chip provided fast floating point arithmetic for the original IBM PC and became part of the x86 architecture used today. One unusual feature of the 8087 is it contained a multi-level ROM (Read-Only Memory) that stored two […]

Sega System 16 security reverse engineering

Reverse engineering of Sega’s System 16 Hitachi FD1089 cpu security module by Eduardo Cruz: I’m glad to announce the successful reverse engineering of Sega’s System 16 cpu security modules. This development will enable collectors worldwide preserving hardware unmodified, and stop the general discarding of Hitachi FD modules. The project is right now involving external testers so […]

A journey into Capcom’s CPS2 silicon – part 3

Eduardo Cruz published the third and last post in the Capcom CPS2 reverse engineering series we covered previously: For many years, finding how and where did Capcom hid away its security implementation has been a pending critical task for the arcade community. CPS2 systems running out of battery were rendered useless forcing collectors worldwide to […]

Inside the 76477 space invaders sound effect chip: Digital logic implemented with I2L

Ken Shirriff has written an excellent in-depth look at the 76477 sound effects chip: The 76477 Complex Sound Generation chip (1978) provided sound effects for Space Invaders1 and many other video games. It was also a popular hobbyist chip, easy to experiment with and available at Radio Shack. I reverse-engineered the chip from die photos […]

A journey into Capcom’s CPS2 silicon – Part 2

Here’s an informative part 2 of the Capcom CPS2 reverse engineering series by Eduardo Cruz: Capcom’s Play System 2, also known as CPS2, was a new arcade platform introduced in 1993 and a firm call on bootlegging. Featuring similar but improved specs to its predecessor CPS1, the system introduced a new security architecture that gave Capcom for […]