In MacBook keyboard woes, a weird echo of the TRS-80 circa 1978

With technology, whaat goess arounnd comess arouund.

In MacBook keyboard woes, a weird echo of the TRS-80 circa 1978
[Photo: Dave Jones/Wikimedia Commons]

Wall Street Journal personal technology columnist Joanna Stern’s MacBook Air is driving her bonkers. Though only four months old, its keyboard is repeating characters as she types–or failing to register them at all. Other MacBook owners report similar misbehavior, which has been going on for awhile and inspired a class-action lawsuit.


The errors Stern and others have encountered stem from an Apple keyboard design that debuted in the thin and light 2015 MacBook and has since spread, in modified form, across the company’s entire portable line. In a statement, Apple acknowledged the defect and apologized for it, while saying that the number of users impacted is small.

Stern calls the fact that MacBooks have trouble properly registering input “a bizarrely 21st-century problem.” But as I read her column, it dawned on me that it’s pretty much the same hardware failure that I encountered as a junior high school student in 1978, when my father brought home a TRS-80 microcomputer from Radio Shack (which, honoring the company’s later rebranding, I will grudgingly refer to as “RadioShack” for the remainder of this article).

Early TRS-80s had a tendency to register multiple key presses when you’d tapped a key only once, resulting in repeated characters. We users called this behavior “keybounce” at the time, and it made our computing lives miserable for awhile–though there was a happy ending which I’ll get to in a bit.

Character flaws

Just to evocatively convey her frustration with her MacBook Air, Stern published her WSJ story with repeated and skipped characters (and the ability to undo the errors by flipping switches embedded in the text). Here she is on why some MacBook keyboards repeat (or skip) characters, with extra Es for your reading pleasure:

Most likeely culprits? Dust and deebris. But you don’t havee to so much as eeat a Saltinee oveer your keeyboard to eexpeerieencee thee issuees…Applee’s butteerfly meechanism, likee a reeal butteerfly, has two deelicatee wings that allow thee keeyboard to bee neearly a millimeeteer shorteer. But someetimees wheen dust geets in–eeveen someething as small as a grain of sand–it jams up, says Kylee Wieens, chieef eexeecutivee of iFixit, which teears down eeleectronics to eevaluatee how eeasy theey aree to reepair.

Stern’s explanation of why MacBook input goes awry echoes RadioShack’s own explanation of the TRS-80’s keyboard flaw, which it cheerfully detailed in a small front-page item in the November 1978 issue of its newsletter for TRS-80 owners, admitting that the problem was widespread and even using its catchy nickname:


Many of you have experienced what we call “Keybounce”–multiple letters from one keystroke. In almost every case it is traceable to contaminated key contacts. It can be dust, dirt, cigarette smoke, or almost any kind of residue. Usually, this doesn’t occur except in Level II computers, and after some use.

Over at, an excellent article by Matthew Reed explains how TRS-80 mavens dealt with the curse of keybounce:

The recommended approach was to either use a paper clip bent into a “J” shape or a plastic comb to pry up an individual keycap. (Using a screwdriver wasn’t recommended because the metal of the screwdriver could create nicks in the plastic of the keycaps.) Once a keycap was removed, the metal prongs in the key switch were visible and could be carefully cleaned.

Techniques for cleaning the prongs were varied. Using compressed air was a common approach. Some people used alcohol or even a rubber eraser. Radio Shack recommended applying their Color TV Tuner Cleaner (catalog number 64-2320) to a cotton swab and using it to gently clean the prongs. Other people, including Dennis Báthory-Kitsz, felt that using tuner cleaner was a bad idea as it ran the risk of turning any remaining dirt into a “dusty mudpile.”

With Apple’s MacBook keyboard, one of the issues seems to be that the butterfly mechanisms are fragile beasts: If you pry off the keycap to clean their innards, you risk damaging them. Which is why I have blown the occasional puff of compressed air into the M key on my own MacBook Air–the only one which occasionally sticks–but have otherwise avoided invasive surgery. (Apple’s own instructions for cleaning MacBook keyboards involve canned air but no keycap removal.)

Back in 1978, we TRS-80 aficionados found keybounce maddening. But as PC pioneers, maybe we also considered dealing with it to be a badge of honor. In the February 1980 issue of 80 Micromputing, the aforementioned Báthory-Kitsz used the same gag that Stern perfected 39 years later:

Eeven critics will admit the wworld’s first popular microcomputer wwas designed successfully–its hardware has bbeen reliable and its software vversatile. Other than a few areas RRadio Shack chose to igonore, or disagreements about physical or electronic aesthetics, the TRS-80 has few outright flaws. By now you have gguessed month’s topic…that ffamiliar kkeybounce.

Báthory-Kitsz was introducing a utility he’d written that fixed keybounce by detecting if a keypress was registered twice in such quick succession that it was likely a bounce rather than willful input. At a litle over 100 bytes, his program was short enough that he included it in his column so readers could type it in themselves. RadioShack issued a similar piece of software of its own, KBFIX. It later built debouncing into the TRS-80’s ROM and then switched to a better keyboard that wasn’t susceptible to bouncing. Problem solved.

Flash forward four decades. As Stern notes, Apple has already revised its original butterfly-switch keyboard by adding membranes designed to keep detritus from messing with the mechanisms. But the fix hasn’t entirely eliminated missed and repeated characters.


Meanwhile, a Mac user named Xinhong Sam Liu has written a piece of software called Unshaky. Like Báthory-Kitsz’s utility and RadioShack’s KBFIX, it monitors input and aims to ignore multiple keyboard presses that appear to be due to misbehaving switches. Stern says it’s worked well for her, which suggests that Apple should implement something similar as part of MacOS.

But even if most MacBook purchasers never encounter keyboard hell in the first place–and no matter how little Apple enjoys admitting that the defect exists at all–the harm to the company’s reputation is real. If Apple takes the matter seriously, it ought to be able to give us a keyboard that can’t be felled by a speck of dust–unless you think that RadioShack was capable of feats in the 1970s that Apple cannot achieve in 2019.

About the author

Harry McCracken is the technology editor for Fast Company, based in San Francisco. In past lives, he was editor at large for Time magazine, founder and editor of Technologizer, and editor of PC World.