PS/2 vs USB

What is best for keyboards?
What is best for mices?

PS/2 has far less latency

USB

SPI is the best

polling is way too fast for you to notice USB's weakness to PS/2. PS/2 is also more prone to failure at the plug

I'm actually working on trademarking a new type of IO interface for a keyboard that has one pin per key, and supports unicode keyboards as I'm hoping that one day charmap will be obsolete and keyboards will have all those keys on them one day

...

> PCIe 4.0 x16 keyboard riser card


great idea

Generally USB because of hotswapping. For keyboards also USB because you may as well have backlighting.
For mice PS/2 is fine but if they're wireless you need USB.
If interrupt had a modern interface maybe it would stand a chance outside of generic peripherals that don't get unplugged.

inb4 different plugs for 80%, 60% and other memeboards

old coworkers used to hotswap ps/2 like a bunch of fucking kike retards. "no user its alright to do that"

Chad PS/2.

>mices

Mousii

well with USB you have the USB controller kindly asking the CPU to process your input.

With PS2 the controller fucking takes over the whole CPU and make it process your input, because your're the fucking owner of the computer and he's the one who must bend to your will, and not the other way around

mouses

PS/2 because it leaves a free USB port.
USB is bad enough as it is, cramming all the ports on your PC is asking for trouble.

different pinouts, same plug
The idea is reasonably good, could make creating a makeshift keyboard easier/cheaper, possibly interchangeable cables from keyboard to pc so you buy the cable separate, ultimately making the keyboard slightly cheaper due to less parts.

but we moved to smaller and easier to use pieces, your shit may have been better back in the day, but wouldn't fly now.

mice and keyboards don't get unplugged outside of hardware failure.

backlighting is fucking retarded to boot, with the keyboards I have used, backlighting was never an issue because having the setting low enough to not be a problem also meant that a monitor would illuminate the keyboard better than the keys do, and if the keyboard was that bright, it's distracting.

keyboard
ps/2

for mice, you likely are not going to find a working mouse, or a good mouse that demands ps/2, most likely you will have one that can run ps/2 but will default to usb.

personally greatly prefer ps/2 but recognize it has its place with keyboards not mice.

ps2 is best for keyboards because it is low latency. admittedly it's difficult to get a ps2 keyboard with n key rollover but there are mods that can be done.
usb is current the best for mice because ps2 has a max polling rate of 125 hz without overclocking. this causes spinouts in fps.
personally i think an rs232 mouse would be superior to ps2 and usb because the port is interrupt based and 115200 baud = 11520/8 = 1440hz
i used an rs232 ball mouse for years and it had excellent driver support.

...

PS/2 is objectively better for both.

ps/2 has

blocking ghosting rollover bouncing etc, look it up

mice is fine usb i think

However, PS/2 ports continue to be included on many computer motherboards, and are favoured by some users, for various reasons including:

They cause fewer problems when KVM switching with non-Wintel systems.[citation needed]
PS/2 ports may also be favored for security reasons in a corporate environment as they allow USB ports to be totally disabled, preventing the connection of any USB removable disks and malicious USB devices.[5]
High-end keyboards that provide full n-key rollover typically do so via a PS/2 interface as, though USB HID keyboards support full rollover, some operating systems do not promote USB HID boot keyboards, which can report only a maximum of six pressed keys (excluding modifiers) at a time.[6] This hinders fast typists, as well as users who depend on unusual hotkeys to be recognized by special software (for example, for system development purposes) or seek to use alternative input methods like Braille or chorded input.
The PS/2 interface also has much lower latencies for keyboards due to the interrupt-driven manner PS/2 keyboards communicate with the computer by default compared to the polled nature of USB keyboards where the USB controller hardware polls USB keyboards, which can be important in some real-time applications or gaming.[citation needed]

USB keyboards return status updates by default every half second in order to allow typematic (the function that causes keys to repeat when they are held long enough) to work[7] compared to PS/2 keyboards which do not return any status reports unless their status changes or are polled or a key is held long enough for typematic to activate, which causes the keyboard to send the scan codes for the keys affected by typematic to be repeatedly sent until the keys are released.
The PS/2 interface saves power due to its interrupt-driven nature compared to USB which requires periodic polling, so it is a popular interface for laptops' internal keyboards and pointing devices.

USB mice have lower latencies than PS/2 mice because standard USB mice are polled at a default rate of 125 hertz while standard PS/2 mice send interrupts at a default rate of 100 hertz when they have data to send to the computer.[8][9] Also, USB mice do not cause the USB controller to interrupt the system when they have no status change to report according to the USB HID specification's default profile for mice.[7] Both PS/2 and USB allow the sample rate to be overridden, with PS/2 supporting a sampling rate of up to 200 hertz[1] and USB supporting a polling rate up to 1 kilohertz[8] as long as the mouse runs at full-speed USB speeds or higher.

Fuck you I2C masterrace

always keep a PS/2 keyboard around.
If you ever have to jump into the bios after a complete wipe there's a good chance your bios won't even detect the USB device.
Whether or not you use PS/2 afterwards is personal preference.

> possibly interchangeable cables from keyboard to pc so you buy the cable separate,
Why would that be specific to his retarded connector? You can do that today

PS/2

because a cable with a 100~ letter pinout would be expensive, but a potentially 1 time purchase.

the upfront cost may be large, the the long term would be low.

PS2 is better hardware wise but USB does have better polling rate. Serial will always have best input connector

can modern usb keyboards and mice be connected to ps2 with adapters?

Depends on the model

what happens if an incompatible model is connected that way?

But Linus told me random PS2 unplugs are bad too!

It doesn't work

>everything I don't like is gay

>USB does have better polling rate
PS/2 doesn't have a fucking polling rate. It interrupts the CPU with its inputs.

Kek

Wouldn't PS/2 be the best option for Desktop systems? I mean you probably wouldn't be unplugging your keyboard much, if at all, so it makes sense, right?
Am I retarted?

I agree. But we need a new port which wouldn't get disabled by removing a device from it, yet still use interrupts as a means of communication with CPU.

>a new port which wouldn't get disabled by removing a device from it, yet still use interrupts as a means of communication with CPU.
Yeah that would be ideal, but for the time being, like I said, for desktops where you're not going to be unplugging the keeb much anyway, PS/2 sounds like a good deal.

why did usb keyboards even become a thing?

Keyboards suck when hooked over USB, HID limits them to 6 keys plus modifiers pressed at once, keyboards that let you press more will pretend to be multiple devices to avoid this limit. Some keyboards have NKRO only over PS/2.
When it comes to mice, though, USB is the way to go, as PS/2 is limited to around 100Hz, which is below even your cheapo 125Hz mouse.
Oh, and there's the whole hot-swapping thing, which you can't do with PS/2 ports.
>tfw no laptops with PS/2 ports

usually you can unplug and plug back and it will just work. must be some shitty implementation if it does not work.

isnt that a problem that could be fixed by changing the hid implementation code?

One-Wire masterrace.

But Macs use SPI and they are gay.

why would you ever want to press over 6 keys at same time? i cant think of any legit use for that.

You have 10 fingers on hand and 10 more on feet. So keyboard must be able to proceed 10+ keystrokes at time

I have an old ps/2 dell quietkey from the 90s, so I still use it to this day. it's pretty good

I use a usb mouse though since I haven't see a ps/2 mouse in a very long time

I use a lot of keys while gaming. w+d or a when circle strafing then space as well for jumping. add in ptt for voip, change weapons and it all adds up.

Multiple people can press keys on the same keyboard as well, not to mention that you can press multiple keys with a single finger.
There's also keyboard jamming, which can get in your way even when you don't press many keys.

IT convenience, it's user friendly and less likely to get damaged

so in other words, PS/2 is better, but USB is retard-proof.

>PS/2 has far less latency
>ps2 is best for keyboards because it is low latency.

keyboard latency barely matter whatsoever in comparison to mouse latency.
there is already ~15ms debounce latency in every keyboard that very few people even realize exists.

>mices

I use PS2 for my keyboard (IBM MODEL M from 1996) but it is because my keyboard is PS2. I wouldn't use it otherwise.

but i can just use USB-C on many of my keyboards already with interchangable cords that don't cost an arm and a leg

It was poor wording but his point is that USB has less latency, PS/2 may use interrupts over polling but USB keyboards are polled faster than a PS/2 keyboard is capable of sending interrupts.

fake news

yeah but in games you usually have one hand on the mouse, leaving you with only 5 fingers on on your keyboard.

In general it doesn't really matter. I usually use USB because my keyboard is USB. I have some PS/2 keyboards and in actual use, there's no practical difference.
Even at a polling rate of 250hz, you'll be introducing less than 4ms of latency.
Hotswapping keyboards is occasionally useful as well, I occasionally have to plug one into my home server when networking goes tits up for example.
USB can do more than 6kro as well by functioning as multiple devices or using some of the newer HID functionality.
Latency is basically not an issue outside of games and debounce protection in keyboards is going to introduce far more lag than USB polling will.

Not an argument

It depends on what makes it better for you, all of mine are wireless bc I don't want to deal with the cables hanging around and makes them more portable. So they need to be USB

Well yeah obviously wireless keebs would need to be USB, but I'm talking about for wired

read what he said
>I'm actually working on trademarking a new type of IO interface for a keyboard that has one pin per key, and supports unicode keyboards as I'm hoping that one day charmap will be obsolete and keyboards will have all those keys on them one day

Had a friend who played an mmo, managed to play 6 accounts at a time, and play them better then most normal people could play one, because he mapped hotkeys to pressing multiple buttons for different windows, so shift+ctrl+q+w+a+s would be a key he used for one window while hitting right shift +ctrl+[+]+' for another

watching him do this shit in real life was fucking amazing. An all around useless skill sure, but amazing nonetheless.