The TV Jack was a series of consoles released in Japan in the late 70s. The first console to be released was the Jack 1000, which entered Japans shops in 1977.
The Jack 1000 was similar to a lot of PONG systems. It had two paddle controllers attached to the system and 4 built in colour games: Hockey, Practice, Racquetball and Tennis.
Just a few months later, Bandai released the Jack 1200. The main addition to this console was the addition of two detachable controllers. The original controllers attached to the console remained allowing 4 players to play Tennis, Hockey and Racquetball.
The next release was the TV Jack 1500. The console had cored joysticks with a fire button instead of paddles. It also had 4 more games added including Soccer and Badminton.
The TV Jack 2500 was a remake of the original TV Jack 1000. It was much smaller than the original and there was 5 variations of each game (instead of just one).
The TV Jack 3000 was similar to the TV Jack 1200 in design. It had 4 paddle controllers: 2 on the system and 2 detachable. The detachable controllers were stored neatly on the console itself. It also had 10 built in games.
The TV Jack 5000 was the first in the series to use cartridges instead of built in games, however the games were not programmable (i.e. did not use ROM). The system had two joystick controllers.
The last console in the series was the TV Jack 8000. This system was also cartridge based but unlike the 5000, all cartridges were programmable (it was the first console in Japan to have ROM cartridges).
Bandai became the distributor for the Mattel Intellivision in Japan, which took the company in a different direction. Specifically, they stopped producing and marketing the TV Jack series.
Below is a good video review of the Jack 1500, which was one of the most popular consoles in the series.