It will allow you to connect either a PS/2 keyboard or a USB keyboard in fallback mode to the Expert using an ATMega328P and a bespoke DIN-13 to DB-13 cable.

Macs are compatible with just about any standard USB keyboard, including those made by Microsoft. Even a PS/2 keyboard can be used with a Mac as long as you have a PS/2-to-USB adapter, which can ...

Some of the Logitech ones won't work with Microsoft mice, and vice versa, even.<BR><BR>They do make generic PS/2-USB adapters (Belkin has one), but you want the other way around, and that just ...

The USB port on [Deater’s] PCB, by the way, allows you to connect some USB keyboards that fall back to PS/2 mode with an adapter. You can’t just plug any USB keyboard into it.