Hidden in plain sight. 80s developers often went beyond what was generally accepted as a system's limit. They were true pioneers, pushing systems way beyond their initial hardware restrictions. Geoff Crammond is probably best known for his stroke of genius when designing the Formula One Grand Prix games. However, his talent was visible much earlier when his game Revs (1985) was released. The most remarkable thing about it was how it hid code in the sky and used extreme memory-packing tricks on a 32KB 8-bit machine. Because of the BBC Micro’s memory limits, Crammond stored part of the actual game code inside the screen memory area. Normally this would show up as garbage pixels. Instead, he used timer-based palette tricks so those “garbage code pixels” were forced to blue. They disappeared into the sky and became invisible during play.This is the famous “code in the sky” technique. Revs is widely regarded as a landmark of 8-bit programming efficiency and a key ancestor of modern sim racing.