Repairing a vintage 40-kilovolt xenon lamp igniter

What do xenon lamps and the invention of radio have in common? The box below is a 1960s German high voltage unit that CuriousMarc obtain... | Continue reading

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@righto.com | 4 years ago

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 ... | Continue reading

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@righto.com | 4 years ago

The core memory inside a Saturn V rocket's computer

The Launch Vehicle Digital Computer (LVDC) had a key role in the Apollo Moon mission, guiding and controlling the Saturn V rocket. Like most... | Continue reading

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@righto.com | 4 years ago

The digital clock from a Soyuz spacecraft

We recently obtained a clock that flew on a Soyuz space mission. 1 The clock, manufactured in 1984, contains over 100 integrated circuits o... | Continue reading

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@righto.com | 4 years ago

Transformers Used as Read Only Memory

I recently came across a Transformer Read-Only Storage (TROS) module that stored microcode in an IBM System/360 mainframe computer. This unu... | Continue reading

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@righto.com | 4 years ago

IBM, sonic delay lines, and the history of the 80×24 display

What explains the popularity of terminals with 80×24 and 80×25 displays? A recent blog post " 80x25 " motivated me to investigate this. The ... | Continue reading

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@righto.com | 4 years ago

A Visit to the Large Scale Systems Museum

I didn't expect to find two floors filled with vintage computers in a sleepy town outside Pittsburgh. But that's the location of the Large S... | Continue reading

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@righto.com | 4 years ago

“special register groups” invaded computer dictionaries for decades

Half a century ago, the puzzling phrase "special register groups" started showing up in definitions of "CPU", and it is still there. In this... | Continue reading

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@righto.com | 4 years ago

A Visit to the Large Scale Systems Museum

I didn't expect to find two floors filled with vintage computers in a sleepy town outside Pittsburgh. But that's the location of the Large S... | Continue reading

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@righto.com | 4 years ago

Reverse-engineering precision op amps from a 1969 analog computer

We are restoring a vintage 1 computer that CuriousMarc recently obtained. Analog computers were formerly popular for fast scientific compu... | Continue reading

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@righto.com | 4 years ago

Apollo Guidance Computer switching power supply works after 50 years

We recently restored an Apollo Guidance Computer, the revolutionary computer that helped navigate to the Moon and land on its surface. 1 At... | Continue reading

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@righto.com | 4 years ago

Looking inside a 1970s PROM chip that stores data in microscopic fuses

The MMI 5300 was a memory chip from the early 1970s, storing 1024 bits in tiny fuses. 1 Unlike regular RAM chips, this was a PROM ( Progra... | Continue reading

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@righto.com | 4 years ago

Bitcoin mining on an Apollo Guidance Computer: 10.3 seconds per hash

We've been restoring an Apollo Guidance Computer 1 . Now that we have the world's only working AGC, I decided to write some code for it. Try... | Continue reading

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@righto.com | 4 years ago

Software Woven into Wire: Core Rope and the Apollo Guidance Computer

Onboard the Apollo spacecraft, the revolutionary Apollo Guidance Computer helped navigate to the Moon and land on its surface. One of the f... | Continue reading

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@righto.com | 4 years ago

A look at IBM S/360 core memory: In the 1960s, 128 kilobytes weighed 610 pounds

I recently received a vintage core memory array, part of an IBM System/360 mainframe computer. These arrays were used in a 128-kilobyte core... | Continue reading

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@righto.com | 5 years ago

Iconic consoles of the IBM System/360 mainframes, 55 years old today

The IBM System/360 was a groundbreaking family of mainframe computers announced on April 7, 1964. Designing the System/360 was an extremely... | Continue reading

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@righto.com | 5 years ago

The Apollo Guidance Computer's Core Memory

The Apollo Guidance Computer (AGC) provided guidance, navigation and control onboard the Apollo flights to the Moon. This historic computer ... | Continue reading

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@righto.com | 5 years ago

Hammer time: fixing the printer on a vintage IBM 1401 mainframe

The Computer History Museum has two operational IBM 1401 computers used for demos but one of the printers stopped working a few weeks ago.... | Continue reading

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@righto.com | 5 years ago

Reverse engineering the ARM1 processor's microinstructions

This article looks at how the ARM1 processor executes instructions. Unexpectedly, the ARM1 uses microcode, executing multiple microinstruct... | Continue reading

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@righto.com | 5 years ago

Bad relay: Fixing the card reader for a vintage IBM 1401 mainframe

As soon as we finished repairing a printer failure at the Computer History Museum , Murphy's law struck and the card reader started malfunc... | Continue reading

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@righto.com | 5 years ago

Inside the die of Intel's 8087 coprocessor chip, root of modern floating point

Looking inside the Intel 8087, an early floating point chip, I noticed an interesting feature on the die: the substrate bias generation circ... | Continue reading

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@righto.com | 5 years ago

Silicon die analysis: inside an op amp with interesting “butterfly” transistors

Some integrated circuits have very interesting dies under a microscope, like the chip below with designs that look kind of like butterflies.... | Continue reading

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@righto.com | 5 years ago