It's a standard DIN connector. The Omnikey is compatible with both XT and AT, depending on the DIP switch config. All you need is a passive DIN-PS/2 adapter and it'll work with PS/2. The PS/2 can then be put into a Belkin or Blue Cube.
EDIT: There is a manual for the keyboard available on Deskthority. For PC/AT compatibility and standard layout, all the DIP switches should be in the off (down) position.