The 1kB Challenge

Microprocessors didn't always have Gigabytes of memory, and Microcontrollers didn't always have hundreds of kB of flash. The Hackaday 1kB challenge is a contest where entrants must create a device which uses 1kB or less of executable program code. The contest is open to any microcontroller or microprocessor architecture. Anything from Arduino board with AtMega328's to ARM and beyond. External hardware such as leds, switches, and 74 series logic chips are allowed and encouraged - but the machine code must be less than 1kB.