Flicker

Flicker is a one-of-a-kind solid-state engineering prototype built by Bally, converting an electro-mechanical 1975 Bally 'Flicker' (serial #1074) into a test bed for what became known as the "Bally Brain" — a small microprocessor board, based on the Intel 4004 (the world's first single-chip microprocessor), that plugged into the backbox motherboard. It was designed by engineer Jeff Frederiksen of Dave Nutting Associates, with artwork by Dick White.

Unlike the EM version, hitting the A-B-C-D targets in sequence on this prototype awards extra bonus points in addition to lighting the double bonus, adding a layer of strategy to the show-business-themed game.

As the only unit ever built, this prototype's significance goes well beyond its own gameplay: it laid the technical groundwork for solid-state pinball, directly informing later machines such as Mirco Games' 1975 'Spirit of 76.' The original Bally Brain card was lost at some point before 1998, when the prototype was rediscovered and its historical importance recognized; the card was later recreated in 2011 and reinstalled in the machine.