Out of curiosity, what is the practical use of full N-key rollover? I can’t think of many things that require me to press more than maybe five keys at a time.
Used to have these problems when we were children and playing fighting games with my brother with one keyboard or guitar hero clones that need you to press multiple buttons at the same time, that’s the only use case I could think of. I don’t know if there’s any modern software that requires you to mash more than 2 or 3 buttons at the same time
Bit of a niche use-case, but I’d like to have it for using my laptop keyboard as a piano keyboard, for basically MIDI input (via VMPK or one of the DAWs with this feature built-in).
There’s even certain combinations of just 4 keys, which I simply cannot play…
How about a fancy IBM keyboard? The Model F from 1981 features n-key rollover. Don’t ask me why they needed it at the time though. It probably wasn’t important as the Model M from a couple of years later dropped that feature.
Nothing to do with the interface. If your keyboard can only do 4 it means that the manufacturer has cheaped out on diodes and couldn’t even be bothered to stagger the matrix enough to make you not notice.
I recall NKRO was the selling point on some of those keyboards, my old steel series mechanical will absolutely let you mash all the keys with a ps2 adapter.
USB: Many designs and revisions, none of them perfect
Nah, USB 3.2 Gen 2x2 SuperSpeed is the best! And it took me only 30 minutes of reading articles and wiki pages to get that information! althoughI’mnotsurewhatUSB4Gen3×1is,butit’sonlyx1socan’tbethatgood,right?
I know this is a shitpost, but what’s interesting is that even though USB doesn’t directly interrupt the CPU it’s still faster. USB is able to get the entire packet sent before PS2 even sends one. It’s very interesting. So if you ever see anyone unironically saying there is less latency call them out!
Are PS/2 ports still operating on hardware interrupts these days? I would expect these to be emulated as USB devices at this point, depending on whatever I/O chipset is in play.
The bit about USB asking the CPU is kinda true? My understanding is that it’s a packet protocol of sorts, so it’s really just writing post-it notes for each button press and leaves them on the CPU’s whiteboard for later.
Yeah but try pressing more than 4 keys at once on the PS2 keyboard and get back to me
That is a limitation of the keyboard not PS/2. Unlike USB which is limited to 10 simultaneous key presses, PS/2 supports full n-key rollover.
USB is not limited to 10, or 6 as is sometimes stated.
https://www.devever.net/~hl/usbnkro
Interesting I did not know that.
This, it’s why I still use the PS2 interface. Full n-key rollover is impossible for me to do without.
USB does not have that limitation.
Ah, had to dig into it. There was a long period of time during which you couldn’t find a USB NKRO keyboard. Seems that has been fixed.
Yeah, pretty much every single keyboard meant for gaming supports NKRO or at least a lot of multi key roll over
Welcome to now!
What’s n-key rollover?
You can press all keys at once and they all register.
What’s the use for that?
Out of curiosity, what is the practical use of full N-key rollover? I can’t think of many things that require me to press more than maybe five keys at a time.
Used to have these problems when we were children and playing fighting games with my brother with one keyboard or guitar hero clones that need you to press multiple buttons at the same time, that’s the only use case I could think of. I don’t know if there’s any modern software that requires you to mash more than 2 or 3 buttons at the same time
Bit of a niche use-case, but I’d like to have it for using my laptop keyboard as a piano keyboard, for basically MIDI input (via VMPK or one of the DAWs with this feature built-in).
There’s even certain combinations of just 4 keys, which I simply cannot play…
If you type really fast, you’ll find it.
Well I never had a fancy gaming keyboard back in the PS2 days lol
How about a fancy IBM keyboard? The Model F from 1981 features n-key rollover. Don’t ask me why they needed it at the time though. It probably wasn’t important as the Model M from a couple of years later dropped that feature.
Dude just switch to vim already
Is CS available in vim yet?
Idk but Doom runs pretty well
Dude, just switch to Webstorm already
Nothing to do with the interface. If your keyboard can only do 4 it means that the manufacturer has cheaped out on diodes and couldn’t even be bothered to stagger the matrix enough to make you not notice.
I think you’re confusing USB and PS/2. USB has (or used to have?) a limit on the number of keys you could press, whereas PS/2 supports n-key rollover.
USB supports NKRO as well as the default 6KRO.
Historically it didn’t support it though, whereas PS/2 always did.
Historically computers only supported punch cards, it feels weird to only focus on past capabilities. https://www.devever.net/~hl/usbnkro
I mean… the post is about PS/2, which is a past capability too.
The site you linked to just shows a blank page for me in Firefox. Works in Chrome though.
Works fine for me in Firefox for Android. Weird. Everyday I remind myself how happy I am that I’m not a frontend dev lol.
Huh yeah, it works on my phone but not on my PC. Not sure why.
Preposterous, I’ve used emacs on a ps2 keyboard without issues.
I recall NKRO was the selling point on some of those keyboards, my old steel series mechanical will absolutely let you mash all the keys with a ps2 adapter.
Ok, but why would you ever? Genuinely curios.
Video games
Never had issues with it, but fair. Different strokes.
Try playing a rhythm game on a most PS2 keyboards 😟
Also with certain button combinations it was less than 4. You could only hold 2 arrow keys down at a time.
Nah, USB 3.2 Gen 2x2 SuperSpeed is the best! And it took me only 30 minutes of reading articles and wiki pages to get that information! although I’m not sure what USB4 Gen 3×1 is, but it’s only x1 so can’t be that good, right?
It’s the initialisation mode of USB 40Gbps, luckily not something users will have to deal with
I know this is a shitpost, but what’s interesting is that even though USB doesn’t directly interrupt the CPU it’s still faster. USB is able to get the entire packet sent before PS2 even sends one. It’s very interesting. So if you ever see anyone unironically saying there is less latency call them out!
Are PS/2 ports still operating on hardware interrupts these days? I would expect these to be emulated as USB devices at this point, depending on whatever I/O chipset is in play.
The bit about USB asking the CPU is kinda true? My understanding is that it’s a packet protocol of sorts, so it’s really just writing post-it notes for each button press and leaves them on the CPU’s whiteboard for later.
Yes, it’s true the the USB protocol has to “wait” but it gets the message sent so much faster that it doesn’t matter. Still interesting stuff though!
Love it