The Microvision was the very first handheld game console that used interchangeable cartridges. It was released by the Milton Bradley Company in November 1979. The Microvision was designed by Jay Smith, the engineer who would later design the Vectrex gaming console. The Microvision's combination of portability and a cartridge-based system led to moderate success, with Smith Engineering grossing $8 million in the first year of the system's release. The handheld also appeared in the movie Friday the 13th Part 2. However, very few cartridges, a small screen, and a lack of support from established home video game companies led to its demise in 1981.

The first Microvision cartridges were made with both Intel 8021 and Texas Instruments TMS1100 processors. Due to purchasing issues, Milton Bradley switched to using TMS1100 processors exclusively. The TMS1100 was a more primitive device, but offered more memory and lower power consumption than the 8021. First-revision Microvisions needed two batteries due to the 8021's higher power consumption, but later units (designed for the TMS1100) only had one active battery holder. Even though the battery compartment was designed to allow the two 9-volt batteries to be inserted with proper polarity of positive and negative terminals, when a battery was forcefully improperly oriented, while the other battery was properly oriented, the two batteries would be shorted and they would overheat. The solution was to remove terminals for one of the batteries to prevent this hazard. Due to the high cost of changing production molds, Milton Bradley did not eliminate the second battery compartment, but instead removed its terminals and called it the spare battery holder.

Milton Bradley (November 8, 1836 – May 30, 1911), an American game pioneer, was credited by many with launching the board game industry in North America with Milton Bradley Company.

A native of Vienna, Maine, Bradley grew up in a working-class household in Lowell, Massachusetts. After completing high school he found work as a draftsman before enrolling at the Lawrence Scientific School in Cambridge, Massachusetts. In 1856, he secured employment at the Watson Company in Springfield, Massachusetts. After the company was shuttered during the recession of 1858, he entered business for himself as a mechanical draftsman and patent agent. Later, Bradley pursued lithography and in 1860, he set up the first color lithography shop in Springfield, Massachusetts. Eventually, Bradley moved forward with an idea he had for a board game which he called The Checkered Game of Life, an early version of what later became The Game of Life.

In 2004, he was posthumously inducted into the National Toy Hall of Fame along with George Ditomassi of Milton Bradley Company. Through the 20th century the company he founded in 1860, Milton Bradley Company dominated the production of American games, with titles like Candyland, Operation, and Battleship. The company is now a subsidiary of Pawtucket, Rhode Island-based Hasbro.