The Apple I's built-in computer terminal circuitry was distinctive. All one needed was a keyboard and a television set. Competing machines such as the Altair 8800 generally were programmed with front-mounted toggle switches and used indicator lights (red LEDs, most commonly) for output, and had to be extended with separate hardware to allow connection to a computer terminal or a teletypewriter machine. This made the Apple I an innovative machine for its day. In April 1977, the price was dropped to $475. It continued to be sold through August 1977, despite the introduction of the Apple II in April 1977, which began shipping in June of that year. In October 1977, the Apple I was officially discontinued and removed from Apple's price list. As Wozniak was the only person who could answer most customer support questions about the computer, the company offered Apple I owners discounts and trade-ins for Apple IIs to persuade them to return their computers. These recovered boards were then destroyed by Apple, contributing to their rarity today.