The Entex Adventure Vision

Adventure Vision with its four games stored. Photo courtesy of handheldmuseum.com

Background/History:
The early 1980s was a time for experimentation with video game concepts. The market was new and exciting, and no one really knew what the field's future held. The bulk of the video game industry was in the arcades, but home video game consoles - then led by the Atari 2600 - were a rapidly growing and popular segment as well.
The idea of a system that could be played on the go was an appealing one from the beginning. Systems such as Nintendo's Game and Watch series and Coleco's handheld games were primitive - often playing only one game, with very rudimentary graphics and sound. Attempts to make a proper handheld console with changeable games were stonewalled by the technology simply not being "ready" at an economical price. (The Milton Bradley Microvision tried and failed, but that's for another post)
The self-contained console was a "middle ground" between a traditional console and a handheld. While the self-contained console has considerable weight and size, it has its own electrical outlet and screen, so it doesn't require a television. The Adventure Vision was one of the machines in this small field. The Adventure Vision could be operated as a (very bulky) handheld on batteries or plugged into an AC adapter. It was released in late 1982.

What Makes It Obscure?
Few were sold, and the fragile and unreliable nature of the system means that even fewer survive. Despite being marketed as a "portable" system, if you dropped the system while carrying it would probably be broken. The system has four slots in the top which could store four games; this was ironic, as only four games were ever released, including the pack in game, Defender.  The four games were accurate ports of popular arcade games of the time, but the library ranks among the smallest ever released for a game system. At $80, the system was basically a poor man's Vectrex. The Vectrex, while still considered a commercial failure, was far more successful despite its $200 price tag.
The system had sound that was good enough, but poor graphics. The graphics only displayed in red, and had a resolution of only 150x40 pixels. The system featured a line of 40 vertical LEDs and a spinning mirror inside the system to simulate the 150 horizontal pixels. The graphics had a severe "wobble" to them due to the spinning mirror.

Other Aspects of the System
The system used an Intel 8048 processor running at 733 kilohertz and a National Semiconductor COP411L sound coprocessor running at 52.6 kilohertz.
The controls were a 4 direction joystick and 4 buttons, duplicated on either side of the joystick, for left or right handed players.

The Good, the Bad, and the Ugly
Good: It's a highly prized collector's item, control setup, games are faithful arcade translations.
Bad: Game library of only 4 games, poor graphics and sound.
Ugly: Durability. This system NEEDS to be babied.