The Odyssey 100 dedicated console was released in 1975. It uses a multi-chip discrete component design, which makes it much simpler than all later dedicated consoles Magnavox would eventually release. Magnavox already had a single-chip design in mind that year, but wanted to have a product they could release immediately if Texas Instruments, the supplier of their single video game chips, was unable to deliver in a timely manner.
The Odyssey 100 was designed around four Texas Instruments chips. It has two games (Tennis and Hockey); the tennis game was the inspiration for Pong. Neither game had on-screen scoring and the system used a crude buzzer for sound. The Odyssey 100 is powered by either six "C" batteries or a 9 volt AC adapter. Each player had three knobs for horizontal movement, vertical movement and ball trajectory adjustment ("English").
Source: Wikipedia, "Magnavox Odyssey Series", available under the CC-BY-SA License.