Technology / 

03 Jan 2022

The Fifty Year Computer

In “The computer built to last 50 years”, Lionel Dricot (aka ploum) makes a compelling case for a new type of personal computing device, one designed to last decades and “do timeless activities and do them well”. Altough I have some nits to pick regarding the specifics of how a machine like this might be built and what it might include, the concept itself is a great starting point for discussion.

Rather than looking only at the next incremental improvement in hardware and software, the question of building a computer that will still be useful in five decades forces us to think backwards from high-level, “timeless” use cases that address fundamental human problems. What do people use computers for? Communication, primarily. But also accessing reference information. Writing documents. Reading books and periodicals.

None of these tasks are especially computationally intensive, at least by modern standards. (Sure, there was a time not that long ago, when justifying variable-width text or automatically using ligatures and hinting was considered a reasonably hard problem. Progress moves, but slowly.) The most complex number-crunching a purely text-based machine like this would need to perform would likely be cryptographic calculations: support for modern crypto is a must, in order to interact with modern networks and speak protocols like TLS.

At the risk of a bit of a derail, this is basically the limiting factor on whether a computer is still useful today. If it can run OpenSSL, GnuTLS, or another modern crypto library, you can probably hook it up to the Internet and do networked stuff with it. If it can’t, you can’t – and you’re generally limited to using it in offline roles, or sticking it behind some more modern system and using it as a thin client, which is clever but also cheating.

This results, incidentally, in a sort of floor separating the still-potentially-useful hardware – that which is capable of running modern software – from the true “retro” antiques, which cannot and probably never will. (From what I can tell, the oldest production computer that is still supported by Linux is likely the IBM S/390, released 1990. So if you happen to own one of those, you’re already three-fifths of the way to a 50-year computer!)

Provided there are no game-changing revelations in cryptography in the near future, I expect this dividing line to be largely stable. (Sudden developments in quantum computing could, in the worst case, make anything non-quantum-capable into insecure antiques overnight.) I think we should be able to build a 50-year computer with hardware available on the market today, if it were designed well.

Of course, that “if” is pulling a lot of weight. But that’s the fun of the challenge.