4 ms·

> mostly gotten rid of PS/2 Strangely enough, the most recent motherboard I bought (X570-based) has a PS/2 port for the first time in years. No idea why they

> mostly gotten rid of PS/2 Strangely enough, the most recent motherboard I bought (X570-based) has a PS/2 port for the first time in years. No idea why they seem to be making a comeback, but it is kind of nice to be able to directly plug my old Model M in again.

unixhero 6y ago
There is nothing wrong with PS/2 as a HID input. It could perhaps have better "quality of life" such as reversible inputs, and strong re-pluggable support but that's it.
skocznymroczny 6y ago
PS/2 seems to be popular with higher end mechanical/gamer keyboards, supposedly offering lower latencies.
- Baeocystin 6y ago
  Interesting. I guess technically the board I bought is marketed as a gaming board, too, so that makes sense. It makes me smile a little to think we've entered the era where 'old' tech is making a comeback in niche circles due to its own merits! I remember the keyjamming detection tool my cousin and I had to use to figure out how we could both play Star Control on the same keyboard. Good times.
mypalmike 6y ago
I was just reading up about this a couple days ago. The PS/2 comeback for gaming keyboards stems from the fact that the PS/2 connector is interrupt-driven from the device, whereas USB is polled from the host. So in theory, PS/2 latency should be lower. But in practice there are numerous other factors that tend to outweigh any potential benefit: key debouncing logic time generally overwhelms the total latency, the low ~10kbps throughput limits the effective minimum latency of PS/2 bus messaging, and the fact that even if the bus is interrupt-based, keyboards use polling internally to scan the state of the key matrix. It turns out that the implementation details of the how a keyboard scans the matrix is generally a bigger factor in keyboard latency than which bus is used.

4 ms·

> mostly gotten rid of PS/2 Strangely enough, the most recent motherboard I bought (X570-based) has a PS/2 port for the first time in years. No idea why they

by Baeocystin 6y ago

unixhero 6y ago
There is nothing wrong with PS/2 as a HID input. It could perhaps have better "quality of life" such as reversible inputs, and strong re-pluggable support but that's it.
skocznymroczny 6y ago
PS/2 seems to be popular with higher end mechanical/gamer keyboards, supposedly offering lower latencies.
- Baeocystin 6y ago
  Interesting. I guess technically the board I bought is marketed as a gaming board, too, so that makes sense. It makes me smile a little to think we've entered the era where 'old' tech is making a comeback in niche circles due to its own merits! I remember the keyjamming detection tool my cousin and I had to use to figure out how we could both play Star Control on the same keyboard. Good times.
mypalmike 6y ago
I was just reading up about this a couple days ago. The PS/2 comeback for gaming keyboards stems from the fact that the PS/2 connector is interrupt-driven from the device, whereas USB is polled from the host. So in theory, PS/2 latency should be lower. But in practice there are numerous other factors that tend to outweigh any potential benefit: key debouncing logic time generally overwhelms the total latency, the low ~10kbps throughput limits the effective minimum latency of PS/2 bus messaging, and the fact that even if the bus is interrupt-based, keyboards use polling internally to scan the state of the key matrix. It turns out that the implementation details of the how a keyboard scans the matrix is generally a bigger factor in keyboard latency than which bus is used.