The evolution of the On/Off power switch symbol (2008) (opens in new tab)

> No, the one-inside-a-circle symbol does not indicate a toggle between off and on, as this article "surmises".

According to https://en.wikipedia.org/wiki/Power_symbol#Standards, "one inside a circle", IEC 60417-5010, is a fully-on/fully-off toggle. The "one breaking a circle" symbol, IEC 60417-5009, is a fully-on/standby toggle.

Interesting. I remember when that symbol was first getting used, but I don't remember anyone ever explaining that until you just did now. To me, it always meant "on/off" (counting "standby" as "off"). I thought it was just an artistic way of taking the "1" and "0" that was often used on power toggle switches and combining them into a single symbol for a single pushbutton (the "1" is inside the stylized "0").

Exactly, there's even standards[0] for this.

[0] https://en.wikipedia.org/wiki/Power_symbol#Standards

Indeed, and even in 2008 when this article was written Wikipedia had this explanation

> IEC 5009, the standby symbol (line partially within a broken circle), indicates a sleep mode or low power state. The switch does not fully disconnect the device from its power supply.

https://en.wikipedia.org/w/index.php?title=Power_symbol&oldi...

I think it’s mostly true for modern usage. Powering off a laptop doesn’t fully disconnect power, because the power button is not a true switch but just signals to some power management hardware which is ALWAYS on as long as there is battery charge or plug power — it catches the signal from the “power” button and executes a true power switches to start the computer boot cycle.

I agree that I/O has always been confusing and non-intuitive. O stands for "On"? For "Off"? I means eyes-shut? O means eyes open?

The new symbols aren't any better but the UX of "push this button to turn on or off" combined with obvious lights/etc when something is on has mostly made the semantic meaning of the symbols obsolete to 99% of consumers.

That confused me as well, I never made the connection to 0 and 1 until someone told me

I always assumed it was an abstract representation of a rotary switch like:

https://images.app.goo.gl/MQ81XWMZP2dgqkjN7

Also, a perfect circle would almost never strike me as a zero.

Then there's standard walls switch in Europe, which works whichever way the electrician happened to wire it. And then, existence of "stair switches"[0] means you can't ever rely on directionality being consistent.

Now, let's talk about water faucets and which side is hot, and which one is cold...

--

[0] - Don't know what the formal way for these are; I'm thinking of two switches hooked up in a XOR pattern to the same light - i.e. light turns on when the switches are in opposite positions, and off if they're in the same position.

(US here) -- I remember to install light switches so that the up position is "on" because of a faulty light switch I had decades ago -- the spring holding the position was broken so that, over time, gravity would eventually make it fall to the lower position.

Having the lower position be "off" seems like a good failsafe for that sort of thing. I don't know if that's why the convention, but it is the mechanism that I use to remember what the convention is.

I have actually seen the diamond "start" symbol [0] on ONE consumer-ish appliance! It was an office coffee machine at my old job, big green membrane IEC start button.

These symbols are ubiquitous on industrial kit (and in your car, surprisingly enough), it's kind of a shame they are barely used at all else where. There's a pretty wide vocabulary of symbols.

[0] https://www.iso.org/obp/ui#iec:grs:60417:5104

Oh, printers, inexhaustible source of fun.

My approach for over a decade now has been, before any "manual duplex" printing, to start by marking the top page in the tray with a little arrow pointing upwards, drawn with pencil or pen, in the bottom right corner of the page. I'd then print one page (and/or print a test page), and check the position of the arrow, to learn how the particular printer behaves.

To date, I've probably seen every possible orientation of the arrow on the output. Some printers do insane things to paper.

Likewise the indication (if any) on a sheet-fed scanner tray that tells you whether to put the paper in face up or face down.

I've taken to just writing instructions to myself on that type of thing with a sharpie, using actual text, and/or an actual diagram. It works well with the usual beige plastic. If it's black, I usually put it on a small piece of paper and tape it somewhere it won't interfere with the operation.

Not everything has to be an icon. IMO, bad icons are far worse than no icons.

>"insert the side that already has writing face up, and the side that is blank face down"

More odd that it would be on a printer, but for a scanner, it is telling you that it will scan the side that is face up. For a printer, I'd be willing to be that icon is telling you that it is going to print on the face-up side.

I think it's pretty clear, the fold indicates what should be the top side of the page, and the lines indicate it wants printed side up.

That sort of makes sense if you interpret it as circle/line and not 0/1. A circle for an open vent and a line for a closed vent.

That's still dumb though. Why not use the universal bacon/no bacon icons?

Yeah. I kind of associated I as a continuous line and O a loop which never works (something like infinite loop).

But not he says it conveys 1 and 0... so simple... true or false. That would have been easier on my brains :)

Well I mastered the practice a while ago.

But here you are: cast them to booleans. 1/0 -> true/false