PS/2 connectors were a regression on AT DIN & D sub 9-pin serial for most practical purposes. The only upside of PS/2 was a higher mouse data rate, particularl

PS/2 connectors were a regression on AT DIN & D sub 9-pin serial for most practical purposes. The only upside of PS/2 was a higher mouse data rate, particularly with high monitor refresh rates, made mouse movement smoother. You didn't get this for free in Windows though, you needed a registry tweak to tell the mouse driver to bump the sample rate. The huge downside was that PS/2 peripherals couldn't be inserted when the PC is turned on. They need to be inserted at boot time, and aren't detected if they're plugged in later. And the keyboard and mouse connectors were physically the same but not generally switchable.