Hector Martin

if this is the bar USB had to compete with, yes, USB is actually better, in spite of also being incredibly poorly designed

how did those usb to ps2 adapters work?

either 1) mouse/keyboard that supports both protocols or 2) an active adapter that has an USB host/PS/2 device inside

I don't think the latter exist. Even today, USB mice/keyboards very often are still PS/2 compatible. Back in the day it would've been a hilarious waste of money to make active converters like that.

It's even the only way to get N-key rolllover on many modern keyboards, because it turns out the USB keyboard boot protocol was designed by idiots and limits you to 6 keys, while PS/2 doesn't.

(it's possible to do NKRO over USB, if you break boot protocol compat, but noobdy wants to do that; you can get both with some clever hacks, but it's nontrivial and not documented as a standard)

I've read it recently that modern keyboards finally support something other than boot protocol as Windows XP support becomes less of an issue, and so that has NKRO.