Nintendo once made games for other people’s systems. Like the Atari 2600.
TV ad for the Radio Shack TV Scoreboard, a 1976 pong-type game system.
“The number one video game!”
Not really an ad, but it’s all I could find for the RCA Studio II. The article text is just about readable with good eyes.
The Studio II is often called the worst game console ever released. It was supported by RCA for only a year before being withdrawn.