Recently in CONTINUITY

Monday, April 19, 2021

NASA Ingenuity Mars Helicopter Update

Posted at 20:57 Permalink

HP 9825 Repair Part 4: The Processor Reads and Executes ROM Code

Further probing with the logic analyser, correcting its interpretation of bus signals, board swapping with a working machine, and another mysterious release of magic smoke gets closer to the source of the problem(s).

Posted at 13:01 Permalink

Sunday, April 18, 2021

The High Frontier Documentary Now Available to Stream

The High Frontier, a documentary about the life and work of Gerard K. O'Neill and his vision of the human future in space, is now available on popular streaming services such as iTunes and Google Play. Here is my review of Prof. O'Neill's 1976 book, The High Frontier.

Posted at 20:06 Permalink

The 1831 City Bank of New York Robbery

At the time, the vault of the bank was protected only by two warded locks: one on the front door of the bank and one on the vault. There was no night watchman. The locks were defeated by copied keys. The amount stolen was around US$52 million in today's funny money. Here is more about the heist.

Posted at 13:29 Permalink

Saturday, April 17, 2021

Chain Making Machine

Posted at 10:56 Permalink

Friday, April 16, 2021

HP 9825 Repair Part 3: Logic Analyser and a 43 Year Old Patent to the Rescue

After going about as far as possible with an oscilloscope (although back in the day we went way deeper into the woods with just a ’scope), it's time to hook up a logic analyser and see what the CPU and memory are doing. Aiding in the process is U.S. Patent 4,075,679 [PDF], granted in February, 1978 and assigned to Hewlett-Packard, whose 606 pages contain, inter alia, a complete commented source code listing of the ROM and extensive logic, circuit, and timing diagrams. How deep was the damage to this vintage machine when its power supply went all berserker?

Posted at 13:42 Permalink

The Story of NASA's Space Tracking Ships

In the early days of missile testing and spaceflight, tracking ships allowed covering gaps where satellites in low Earth orbit were out of range of ground-based tracking and control stations. As satellite communication constellations such as NASA's TDRS (Tracking and Data Relay Satellite) matured, the need for such ships diminished and now most have been retired.

Many of NASA's early tracking ships were converted from World War II Liberty ships, many built at the Marinship yards in Sausalito, California. Years later, I named my computer hardware company, Marinchip Systems, after this enterprise and, a few years after that, Autodesk, Inc. had its headquarters at 2320 Marinship Way in Sausalito, on the site of the former shipyard.

Posted at 09:58 Permalink

Thursday, April 15, 2021

Rocket Lab’s CEO Peter Beck on Neutron, Electron Recovery, and Rocket Lab’s Future

Posted at 14:52 Permalink

Wednesday, April 14, 2021

Blockchain as Global, Un-censorable, and Indestructible Library

The book(-let: it's just 104 pages) is Blockchain (Library Futures Series, Book 3).

In 1998, I proposed the “Data Immortality Foundation” to provide for perpetual storage and access to documents and data despite the vicissitudes of time, technology, and coercive governments. Perhaps blockchain technology (not Bitcoin, which would be hideously inefficient for the purpose and prohibitively expensive, but a purpose-built system based upon its fundamental technologies) could provide for a distributed, peer-to-peer, permanent, unalterable, and impossible-to-censor repository for documents and data of all kinds (images, video, sound recordings, raw data from scientific experiments, etc.). Once you have immutable addresses and documents, you can then build a layer on top of it with versioning, citation, and compensation for authors and publishers, and finally realise the dream of Project Xanadu without any central organisation or choke-point where censorship could be applied.

Such a system would, incidentally, make abusive copyrights impotent and obsolete.

Posted at 13:28 Permalink

American Reporters in the Battle of Berlin

Posted at 11:07 Permalink

Tuesday, April 13, 2021

Jet Powered Trains—What Could Possibly Go Wrong?

Posted at 11:28 Permalink

(Badly) Colouring the Past: Colourisation AIs vs. Reality

Here is the complete thread, with additional examples.

Posted at 09:40 Permalink

Monday, April 12, 2021

Sixty Years Ago Today—Yuri Gararin is First to Orbit the Earth

The film First Orbit, released in 2011 to commemorate the fiftieth anniversary of the flight of Vostok 1, re-creates the mission with images from the International Space Station following Gagarin's flight path, with original mission audio and subtitles.

Here is a short film about the making of First Orbit.

Posted at 11:21 Permalink

Sunday, April 11, 2021

HP 9825 Repair Part 2: Is Our Rare 16-Bit Processor Fried?

In Part 1, the catastrophic failure of the power supply was analysed and repaired, but that didn't fix the computer, indicating damage elsewhere as a result. Now the investigation digs deeper into the circuitry, checking the clock generation and memory access signals from the processor. There's excellent background about Hewlett-Packard's pioneering 16-bit processor built from multiple chips on a hybrid substrate.

Posted at 13:59 Permalink

Saturday, April 10, 2021

The Unbeatable Game from the 1960s: Dr NIM

A plastic and marbles mechanical computer that plays Nim.

Posted at 14:12 Permalink

Friday, April 9, 2021

Cold Spot, Planet Nine, and the Axis of Evil: Uncovering the Secrets of the Cosmic Microwave Background

Posted at 14:57 Permalink

Comrades—Save the Mycelium!

Posted at 12:53 Permalink

Thursday, April 8, 2021

“Census Sixty”—The Univac 1105 at the U.S. Census Bureau

This cheesy propaganda film about the 1960 U.S. census has some nice footage (around nine minutes in) of the UNIVAC 1105 vacuum tube computer used in that census and the FOSDIC microfilm scanner which replaced punching Hollerith cards from the data collected by census takers. The Census Bureau, which was a pioneer in punched card tabulation of data, was later one of the first to replace cards with optical document scanning.

Posted at 12:08 Permalink

Wednesday, April 7, 2021

IBM System/360: Announced 57 Years Ago Today

Posted at 18:27 Permalink

Hewlett-Packard 9825T Repair Part 1: Power Supply

In January, 2021, Curious Marc's 1970s vintage Hewlett-Packard 9825 laboratory computer blew up when a single transistor in the power supply failed with a dead short from emitter to collector which placed 13 volts on the +5 power supply rail. This caused one integrated circuit on one of the boards to literally explode, with less apparent damage elsewhere the way to bet. The diagnosis and repair adventure begins with fixing the power supply.

Posted at 14:41 Permalink