Comment on Calculatable
dQw4w9WgXcQ@lemm.ee 2 weeks agoI discovered that hitting something like C, CE and 0 simultaneously for some reason worked as an instant power off for my school calculator. Do calculators have such hidden off-buttons? Because I have discovered other calculators with other combinations.
petrol_sniff_king@lemmy.blahaj.zone 2 weeks ago
There’s actually a neat reason for this! The way that simple keys work, like those in a calculator, is by connecting a circuit and letting a small amount of voltage through. This is usually fine because the keypad is broken up into different rollover zones, which is how multi-key input works. But if you find and press keys that are all in the same zone, their voltages add up and can actually overwhelm the little cpu in there. Really old calculators were really easy to break because designers never thought users would need to press keys like division, multiplication, subtract, add, square and square root all at once, which as you can imagine, caused a massive power spike.
Now, is any of this true? I have no idea dude, you’re calculator was probably fucking haunted or something. I’d have taken that thing to a seance with a ouija board immediately.
T156@lemmy.world 2 weeks ago
Not really, since keys work by shorting the circuit. That’s why pressing multiple keys at once on your keyboard doesn’t cause it to blow up. It would just assume the button with the shortest circuit was pressed, and ignore the rest.
It might cause weird things to happen with a mechanical or electromechanical calculator, since there were physical mechanisms engaged and disnegaged for each function, and might break/jam those, but not an electronic, and especially not a transistorised one.
It’s more likely that hitting them all confused the CPU, or dropped the voltage down enough that it reset, just in case something strange happened, or to try and fix any bug that might have caused it to register all the buttons being pressed.
dQw4w9WgXcQ@lemm.ee 2 weeks ago
I love that you bring a great technical and insightful answer and then just leave with that my calculator is probably posessed.
petrol_sniff_king@lemmy.blahaj.zone 2 weeks ago
I do try.
Not very hard, but still.
bstix@feddit.dk 2 weeks ago
I think this is actually still an issue. On PCs the space bar + up + left arrow keys conflicts on some keyboards. Try it: open Notepad, press two arrow keys and then space. Most of them works but if you hold up and left, it will not make a space.
This is annoying in racing games, when you want to accelerate, turn left and use the hand brake at the same time.
petrol_sniff_king@lemmy.blahaj.zone 2 weeks ago
I don’t know the specifics, but there is such a thing as keyboard rollover. MOST KEYBOARDS—whoa, sorry. Most keyboards support up to 6 keys at once, but it might be that they’re still divided into sections with lower rollover numbers, such as the arrow keys and space. Some “gaming” keyboards support up to 25 though, so your best bet if this bothers you is just upgrading to a spiffier typer.