Let me just check my... WRIST COMPUTER! THAT SHOOTS LASERS!

Douglas Adams had the joke about the phase of an immature civilization's development in which it believes that digital watches are a clever idea. Digital watches are still fairly popular (mostly at the cheap end of the market), and I never had quite the antipathy to them that Adams did; but in that connection, it occurs to me that I've personally witnessed the end of the era in which humanity's nerd vanguard collectively believed that the logical place for any arbitrarily advanced item of personal tech was on one's wrist. For a time in the Eighties I actually wore what you might call a primitive wrist PDA, a Seiko watch that could store a few text messages (you entered them using an incredibly painful browse-the-alphabet-menu interface). And those Casio calculator watches were all over. I never saw one of these, though.

You actually can buy a wrist TV if you go looking for one, but only a high-octane variety of dork would actually wear one (hmm, they seem to be marketing it to obsessive sports fans). As Nathan Shumate observed, the wristphone was a non-starter, even though the necessary technology now exists and it was a perennial dream of futurists.

What are wrist-mounted devices actually good for? Displays that require no interaction, and convey little enough information that you can read them in a tiny format from some distance. That basically means a clock, with possible minor augmentations. I think the space has been pretty much explored.

Speaking of old calculators

I remember seeing this on the Web a while back and being amazed: The Friden EC-130 and its successor the EC-132, four-function RPN desk calculators from 1964-65. They cost about $2000 in 1965 dollars.

While they're primitive and hulking by modern standards, and apparently broke all the time because of a manufacturing problem, they're also beautiful, something you'd expect to see Dave Bowman using to override HAL. The interior was all discrete components, and the stack was displayed on a four-line green vector CRT.

More beautiful oldtech

If I recall correctly, plorkwort managed to obtain a Curta rotary calculator a while back. If you are not so lucky, you can use this Curta simulator (Flash 6 required). There is also a 3D version, but it's frustratingly tricky to manipulate. There is a manual online but since you can't damage the virtual Curta, it's interesting to try to puzzle out for yourself how to do multiplication and division of multi-digit numbers.

Apparently Curt Herzstark designed this astounding machine while he was a prisoner at Buchenwald—the camp commander wanted to give one to Hitler as a victory present. But Herzstark was liberated and the first Curtas were built after the war. Hand-cranked rotary calculators that use a similar principle go back to the 19th century (and have antecedents in the 17th), but one that you can hold in your hand is something else again.