https://en.wikipedia.org/wiki/Bendix_G-15 is the computer that has been restored.

What kinds of programs were available for this machine? I’m really curious what kind of complexity was it capable of running.

It's been said on previous YT videos - the system probally ran civil engineering calculations for building bridges and roads. They may have even been for work in Maryland (the state) where the Bendix 'lives' - at the System Source Museum outside of Baltimore MD. It's down in Texas to get fixed by Usagi.

I'm curious about the economics of this machine.

Wikipedia says it could be rented for $1485/mo, and the average salary in 1956 was $3600 or $300/mo, so it would have to replace 5 people (engineers must have earned more), if you don't count the extra cost of software, power, and maintenance.

I remember from a book on Richard Feynman that a classroom full of bright students was about as fast as the computer the Manhattan Project got, except, of course, the computer didn't get tired.

Not really a computer though - they didn't exist in the USA at the time. If I remember correctly it was a series of IBM calculating devices chained together.

His excitement is infectious. It's hard to not feel giddy at seeing it finally run after all that hard work!

I can't wait to see the kinds of programs we can run on a machine like that, along with discussions about tricks when writing programs for serial memory computers :D

He's been plugging away at this machine for a year and a half - the excitement is well-earned!

At System Source, we have a large collection of software (hard copy, mag tape, paper of software for the Bendix. Many of the manuals have been scanned by our wonderful volunteers https://rbk.delosent.com/g15doc.html

Is anyone immature enough to giggle when they hear the name of the computer?

I’ve been to the System Source Museum many times and it’s well worth the visit if you are in the area. The G15 is a fascinating system, small and compact compared to the huge mainframe-sized contemporaries of the era.

On the topic, the oldest original running computer[1] can be found in the UK in the National Museum of Computing based in Bletchley Park (where Alan Turing and many others worked breaking German cryptography). The museum requires a separate ticket from the "main" Bletchley Park museum. It's around 1h trip from London Euston. Well worth a visit! Among other items, they have a working "Bombe" replica

[1]https://en.m.wikipedia.org/wiki/Harwell_computer

When I visited a couple of years ago, it was quietly clicking away, computing prime numbers.

Not sure if it's still the case, but when I visited, they handed you a button to single-step through the program. You actually get to operate it, at some level.

The oldest running computer anywhere is apparently in one of the Voyager probes. Source: a video about troubleshooting one of them that was posted on HN a while ago.

They were only launched in 1977. I can guarantee you there are 100's of computers that are older than 1977 that are still in active use.

Vastly more than hundreds. For instance I have an HP-65 (https://en.wikipedia.org/wiki/HP-65), a programmable pocket calculator from 1974. It's collectable, but not rare. It is built with similar objectives: low power numerical applications. Of course it has substantially less memory, buit then it was substantially cheaper!

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