We love our retrocomputers here at Hackaday, and we’re always delighted to see someone rescue an historic artefact from the landfill. Sometimes, all it takes is replacing a broken power switch or leaky capacitor; other times you need to bring out the oscilloscope and dig deeper into internal circuitry. But the huge amount of work [Jerry Walker] put into bringing an HP 9830A back on its feet is something you don’t see very often.
If you’re not familiar with the HP 9830A, it’s a desktop computer from the early 1970s, fully built from discrete logic gates. The machine on [Jerry]’s desk turned out to be completely dead, with not even the fan spinning up. This was caused by a dodgy power switch, but replacing that switch was just the beginning: there were several bad components inside the power supply as well as a huge amount of moist dirt on the back of the motherboard. After a thorough cleaning and the replacement of several failed components, all four power rails were running within spec again.
Continue reading “The Epic Journey Of Repairing An HP 9830A Desktop Computer From The 1970s”
Restoring vintage computers is the favorite task of many hardware hackers. Retrocomputing probably makes you think of home computer brands like Commodore, Amiga, or Apple but [Erik Baigar] is deeply into collecting early military computers from the UK-based Elliott company. Earlier this year he made a detailed video that shows how he successfully brought an Elliott 920M from the 1960s back to life.
It is quite amazing that the Elliott company already managed to fit their 1960s computer into a shoebox-sized footprint. As computers had not yet settled on the common 8bit word size back then the Elliott 900 series are rather exotic 18bit or 12bit machines. The 920M was used as a guidance computer for European space rockets in the 1960s and ’70s but also for navigational purposes in fighter jets until as late as 2010.
Opening up the innards of this machine reveals some exotic quirks of early electronics manufacturing. The logic modules contain multilayer PCBs where components were welded instead of soldered onto thin sheets of mylar foil that were then potted in Araldite.
To get the computer running [Erik Baigar] first had to recreate the custom connectors using a milling machine. He then used an Arduino to simulate a paper tape reader and load programs into the machine. An interesting hack is when he makes the memory reading and writing audible by simply placing a radio next to the machine. [Erik Baigar] finishes off his demonstration of the computer by running some classic BASIC games like tic-tac-toe and a maze creator.
If you would like to code your own BASIC programs on more modern hardware you should check out this BASIC interpreter for the Raspberry Pi Pico.
Video after the break.
Continue reading “Listening To The Sounds Of An 1960s Military Computer”
Back in the early dawn of the GUI age, cathode ray tubes were the dominant display technology for the personal computer. In order to avoid burn-in of static display elements, screensavers were devised to help prevent this problem. Out of love for the software of yesteryear, [Greg Kennedy] has put together a bot that posts Windows 3.1 screensavers on Twitter.
A Perl script runs the show in this case. Screensavers are packed into “units”, which are loaded by the script. A basic Windows 3.1 environment is then configured, and loaded into a specially patched DOSBOX that allows automated demo recording in a headless environment. Once up and running, video is recorded of the desktop and subsequent triggering of the screensaver. After a couple of minutes, the recording is stopped, and FFMPEG is used to transcode the video into a Twitter-suitable format. It’s then a simple job of Tweeting the video using the standard API.
It’s a fun project that makes sharing old screensavers easy. Be sure to check out the Twitter feed @dot_scr. If you’re addicted to the vintage aesthetic, try this Apple ][ screensaver hack on your Linux boxen. Video after the break.
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If you are an enthusiast for 1950s computer hardware, you are probably out of luck when it comes to owning a machine of your own. Your best chance will be to join the staff of one of the various museums that preserve and operate these machines, at which you can indulge your passion to your heart’s content. But what if we told you that there is a 1950s computer available for pick-up at any time, to whoever is prepared to go and get it and has suitable transport? You’d be making plans straight away, wouldn’t you? The computer in question is real, but there’s a snag. It’s at the bottom of the Indian Ocean, just at the start of international waters off the coast of Kenya. The story of Kenya’s early computing and how the machine met its fate is the subject of a fascinating article from a year or two ago on owaahh.com that had us riveted from start to finish.
Like large state-owned enterprises worldwide, the Kenyan railway and power monopolies were among the first commercial customers for computing. In the final years of the British Empire, those were ordered from a company in London, International Computers & Tabulators, and it was their ICT1202 that served the railway company. The article goes into detail about the history of the company’s East African operation, the problems of running a tube-based computer in an African climate without air-conditioners, and the 1202’s demise and replacement. We’ll not spill the beans here on how the computer ended up on the seabed and how its replacement ended up being spirited away to China, for that you’ll have to read it all. It’s worth saying, the author also has a personal website in which he goes into much more detail about his experience with computers in the 1950s and ’60s.
Not had enough ancient computer tech? A couple of years ago we toured the primordial electronic computer, Colossus, and also took a look at the National Museum Of Computing that houses it.
I cannot say in words how perfect the venue for our Hackaday Munich party was. Not only was there a gigantic collection of vintage video games just around the corner, there was also a freaking warehouse full of mainframes, tubes, transistors, and some of the old retrocomputers you may have used in the 80s and 90s.
It’s called the Computeum, and without a doubt it is one of the most complete computer museums in Germany. There are fantastic computer museums in the states, but these don’t hold a candle to the pure amount of big iron and silicon found at the Computeum.
Continue reading “The Computeum, One Of The Biggest Computer Museums In Germany”