Space Invaders ROM by Tomohiro Nishikado of Taito Japan
Intel 8080 simulator by Mike Chambers
Coin-up hardware simulation by Kevin Sangeelee
Play Space Invaders
Keys: 3 - Insert Coin, 1/2 Start 1 or 2 Players, Z,X,M - Left, Right, Fire
It's astonishing to think that Nishikado, in the space of about a year, not only wrote Space Invaders, one of the most famous and influential games ever written, but also designed and prototyped the hardware. This included not just an 8-bit microcomputer, but also a custom 16-bit shift peripheral, the video driver, and all the sound effects (they are each dedicated circuits). And he also designed the cabinet.
Microprocessors were a recent invention, so to even have the vision to create Space Invaders would have been an achievement, but to follow this through to market I find literally awesome. It's still a compelling game to play today.