Mini-PAC - Welcome to Ultimarc home page The Mini-PAC is a revolutionary combined Switch/Trackball/Spinner Interface with wiring harness. It is designed so that a complete control panel can be wired up in minutes. Ideal for OEM builders of controllers and cabinets but also suitable for the first-time builder. Harness Power![PDF] Ultimarc Mini-PAC Manual The end of the wiring harness that plugs into the Mini-PAC’s 40-pin header. Note the filled-in “key” at the pin 1 position, on the right. Shown is the “Basic” harness, as it lacks any wiring for spinners & trackballs, which would be to the left, if present.