
PCS used the joystick and keyboard to allow the user to drag and drop playfield elements and even tweak graphics items pixel by pixel. It was inspired by the ultra-influencial work of the Xerox PARC, according to Budge in various interviews. He also revealed that he's a "terrible pinball player" - but is still proud of PCS, because he feels it's a solid piece of programming. Certainly he took the Apple II far beyond what anyone at the time ever believed it could do.
A brief chronology of home computer pinball simulations:
Raster Blaster, Bill Budge, 1981 (based on the pinball table Firepower) The first pinball simulation for computers.
Midnight Magic, David Snider, 1982 (based on Black Knight)
Night Mission, subLOGIC, 1982
PCS in the GameSpy Hall of Fame (many screenshots)
Episode of The Computer Chronicles featuring Budge (13 minutes in)
More info at pcpinball.com