Shady Characters

This is the most recent in a series of one hundred five posts on Miscellany. Start at PART 1 or view ALL POSTS in the series.

Having dispatched punctuation and book news, we’re on to pocket calculators! Incredibly, half a century or more after their appearance, there is still news to be had on the subject.

In the introduction to Empire of the Sum, I mention that like some other animals, ravens and other corvids are known to be able to count. Not only that, but they understand the concept of zero, which is something that humans struggled with for quite some time.1 Now, though, a study in Science shows that not only can crows count, they can count out loud. In the words of the paper’s authors,

crows can flexibly produce variable numbers of one to four vocalizations in response to arbitrary cues associated with numerical values.

That is, trained crows could caw a number of times that corresponded to a visual symbol representing the same number. Astonishing, no? Our own ability to count led ultimately to writing, math, electronics and calculators. We should check in with our corvid neighbours in a few million years to see how their own evolutionary story is coming along.2,3

The first pocket electronic calculators relied on microchips designed especially for them — chips that could add, subtract, multiply and divide decimal numbers, but little else. That changed with Busicom’s exceptionally beige 141-PF,4 a desktop calculator that arrived on the Japanese market in 1971, and which was, for the first time, powered by a programmable CPU. That chip was Intel’s 4004, and it kickstarted a revolution in computing that shows no signs of running out of steam.

Outwardly, the 141-PF was, and I cannot emphasise this enough, a very boring calculator. Rather than use an electronic display, it printed its calculations onto a reel of paper tape, a feature beloved of accountants, but that was the extent of its novelty. Its plastic casing was redolent of cash registers and mundanity.

Yet the 141-PF opened the door for programmable CPUs to be used in more exotic calculators. American readers of a certain age will remember the TI-81 graphing calculators they encountered in high school math class, and which benefited from a CPU called the Zilog Z80.5 The Z80 had been designed by Federico Faggin, one of the 4004’s creators, and it was a roaring success: Z80 chips went on to be used not only in calculators, but also games consoles, home computers (such as the Radio Shack TRS-80 and the Sinclair ZX Spectrum), and a host of other electronic devices.6,7

The Z80 was so successful that it stayed in production for almost half a century; only now, forty-eight years after its development, is manufacturing being wound up.7 In recent years, Z80s were often put to use in “embedded” systems — that is, as general-purpose chips to drive special-purpose devices such as MP3 players, home appliances and aircraft electronics — but this less glamorous occupation should not distract us from the Z80’s staggering longevity. This is a CPU from the dawn of modern computing; a dinosaur that managed to escape extinction. It stayed in production longer than the Ford Model T or the Boeing 707, two other pioneers fêted in their spheres, and, indeed, longer than any of the calculators and computers that it powered.

There isn’t necessarily a pithy anecdote or lesson to be learned here. But if I take away anything from the Z80’s long and productive life, it’s that we live at a time where it is possible to view a sliver of silicon overlaid with microscopically fine circuitry as a commodity — a nugget of logic and memory and wiring ready to be dropped into this gadget and that one without worrying too much about the mechanical and scientific advancements that let us fabricate it in the first place. We are living in a time of wonders, in other words, but it is easy to forget it.

Neatly (?) bookending this post, towards the end of Empire of the Sum I write about what happened to the calculator after its time in the sun. The answer, broadly, is computers. Computers happened, and software happened, and spreadsheets happened. Yet the calculator did not die.

If you pick up your smartphone, you’re very likely to find a calculator app at your fingertips.* The same goes for Windows PCs and Apple’s Macs — in fact, a calculator application of one sort or another has been present on most computers since 1970 or before, when Unix’s dc, or “desktop calculator” program was written for the PDP-11 minicomputer.8

Even so, there is at least one notable calculation desert in today’s computing landscape: at the time of writing, Apple’s popular iPad line of tablet computers lacks a built-in calculator app. Happily, however, this is soon to be remedied. According to the MacRumors website, Apple will incorporate a calculator app in the next big update to its iPadOS operating system, due around September this year.

Is the calculator dead? No, not by a long shot. And if you happen to own an iPad, it is even undergoing something of a resurrection.

1.

Kirschhock, Maximilian E., Helen M. Ditz, and Andreas Nieder. “Behavioral and Neuronal Representation of Numerosity Zero in the Crow”. Journal of Neuroscience 41, no. 22 (June 2, 2021): 4889-4896. https://doi.org/10.1523/JNEUROSCI.0090-21.2021.

 ↢

2.

Starr, Michelle. “Crows Can Actually Count Out Loud, Amazing New Study Shows”. ScienceAlert.

 ↢

3.

Liao, Diana A., Katharina F. Brecht, Lena Veit, and Andreas Nieder. “Crows ‘count’ the Number of Self-Generated Vocalizations”. Science 384, no. 6698 (May 24, 2024): 874-877. https://doi.org/10.1126/science.adl0984.

 ↢

4.

IPSJ Computer Museum. “Busicom 141-PF”. Accessed October 8, 2021.

 ↢

5.

Woerner, Joerg. “Texas Instruments TI-81”. Datamath Calculator Museum.

 ↢

6.

“Chip Hall of Fame: Zilog Z80 Microprocessor”. IEEE Spectrum, June 2017.

 ↢

7.

Maruccia, Alfonso. “The legendary Zilog Z80 CPU is being discontinued after nearly 50 years”. TechSpot.

 ↢

8.

Ritchie, D. M. “The UNIX System: The Evolution of the UNIX Time‐sharing System”. AT&T Bell Laboratories Technical Journal 63, no. 8 (1984). https://doi.org/10.1002/j.1538-7305.1984.tb00054.x.

 ↢

*

You may not own a pocket calculator, in other words, but it is a fair bet that you have one in your pocket anyway. ↢