The arcade trade swaps hard-wired logic for a microprocessor

What happened

Nishikado's original used discrete logic to put two gunfighters on screen, each aiming and firing across obstacles at the other. Midway, holding the American rights, handed the conversion to an outside engineering group that rebuilt the game around an Intel microprocessor, with a separate chip to smooth the motion. The American version looked and sounded better than the Japanese one and sold far more units. More consequential than either was the change underneath: for the first time an arcade game's behavior lived in memory rather than in wiring.

Effects on the people making these machines were immediate. Adjusting difficulty or fixing a flaw meant changing code instead of rerouting a board, one hardware design could carry several different games, and a small team could attempt something more elaborate than a ball bouncing between paddles. Within three years the same processor family was running the game that set off Japan's arcade boom. The trade-off, familiar ever since, was that games now needed programmers, and designing circuits gradually stopped being the job.

The world at the time

Microprocessors were three or four years old in 1975, expensive and mostly discussed as controllers for industrial equipment and calculators. Arcade games were built by engineers who thought in gates and counters, and each new title meant a new board. Taito and Midway had a licensing relationship that moved designs across the Pacific in both directions, a pattern that would define the arcade decade.

What it changed

Programmable boards became the norm within a few years, opening the way to sprites, scrolling, speech and elaborate scoring. The game also put human figures shooting one another on an arcade screen, and objections to that idea surfaced almost at once, sharpening a year later around a driving game that turned pedestrians into targets.