Pete's Test Cart is a special test cartridge created by a hardware engineer at ATARI, INC., named Pete Gerard. This cartridge is used to test and calibrate the controllers and test all color registers. Pete's Test cartridge contains four different tests which are selected by pushing the top and bottom fire buttons: 1) Joystick calibration. 2) Pokey adjust. 3) Gray bar test for shades of grey. 4) Color Bar Test for analyzing color shades.