Missile Command

Boots straight to Missile Command attract mode -- the demo defends its six cities against a rain of ballistic missiles. The trackball is mapped to the on-screen D-pad (and the arrow keys) to sweep the crosshair; the three missile bases fire with Z (left), X (centre) and C (right). Insert a coin with 5 (or the Coin button) and start with 1. Click the screen first so it captures the keyboard. Open the debugger to single-step the 6502, read and write registers and memory, watch the bitmap frame buffer, and set breakpoints and write watchpoints.