Here's a closeup picture of the unknown make/model ROM switcher. It has a beeper on it so when you hold down the "Three Finger Salute" keys long enough, it beeps to let you know that it has switched ROMs. The black wire attaches with a clip to a pin on the 68000 CPU. Ribbon cable goes to the actual ROM socket on the A500 motherboard. The upper left of the board has a molded connector that leads to a single pole, double throw switch (mounted to the back of the computer) to select which ROM to use on power-up.