The Microvision, also known as the Milton Bradley Microvision or MB Microvision, was the first handheld game console that used interchangeable cartridges. This feature allowed the console to be reprogrammed with different games. It was released by the Milton Bradley Company in November 1979 for a retail price of $49.99, which is equivalent to $221.00 in 2025.

The Microvision was designed by Jay Smith, an engineer who later created the Vectrex video game console. The console’s portability and use of cartridges contributed to some success, with Smith Engineering earning $15 million in its first year of release. However, its limited number of games, small screen size, and lack of support from major home video game companies led to its discontinuation in 1981. Satoru Okada, the former head of Nintendo’s R&D1 Department, stated that the Microvision inspired the development of the Game Boy, which followed the Game & Watch series, after Nintendo addressed the Microvision’s limitations.

Production

The Microvision console did not have a built-in computer chip (CPU) like most later consoles. Instead, each game cartridge included its own processor. This meant the console itself only had the controls, an LCD screen, and the device that controlled the screen.

The first Microvision game cartridges used processors made by Intel (called the 8021) and Texas Instruments (called the TMS1100). Because of problems buying the Intel chips, the company changed to using only the TMS1100 processors. This required reprogramming games that had originally been made for the Intel processor. The TMS1100 was simpler but had more memory and used less power than the Intel processor. Early Microvision models needed two batteries because the Intel processor used more power. Later models, designed for the TMS1100, only needed one battery.

The battery compartment was designed to hold two 9-volt batteries with correct positive and negative connections. However, if one battery was inserted incorrectly while the other was correct, the batteries could short and overheat. To fix this, the company removed the electrical connections for one battery to prevent overheating. Because changing the production molds was too expensive, the second battery compartment was kept but labeled as a "spare battery holder" instead of being removed entirely.

Problems

Microvision units and cartridges are now quite rare. Those that remain often face three main issues: screen rot, ESD damage, and keypad destruction.

The manufacturing process used to create the Microvision's LCD was not as advanced as today's methods. Poor sealing and impurities during production caused a problem called screen rot. The liquid crystal inside the screen leaks and permanently darkens, making the game unit still playable but unable to display images properly. While extreme heat can quickly damage the screen, screen rot cannot be prevented in most Microvision systems.

An important design flaw in early units is the lack of ESD protection on the microprocessor inside each cartridge. The microprocessor is directly connected to copper pins that link the cartridge to the Microvision unit. If a user opens the protective sliding door covering the pins, the processor may be exposed to electric charges the user has built up. If the charge is strong enough, it can pass through the door or around its edges, damaging the low-voltage circuit inside the cartridge. This damage can occur from a small electric shock that the user cannot feel. John Elder Robison, a former Milton Bradley engineer, described this issue in his book Look Me in the Eye. He noted that up to 60% of units were returned as defective during the 1979 holiday season, causing concern at Milton Bradley and leading to changes in later units and factory practices to reduce static electricity.

The Microvision unit had a twelve-button keypad with switches covered by a thick layer of flexible plastic. Cartridges had cutouts on their bottom to align with the keypad. Thin printed plastic pieces were placed over the cutouts to label the buttons for different games. However, pressing the buttons stretched the printed plastic, causing it to tear over time. Long fingernails made this problem worse. Many early games provided feedback only when a key was released, not when it was pressed. This led users to press harder, as they did not feel the key being pressed. The issue arose because the keypad used during testing had tactile feedback (a physical feeling when pressed), but the final production keypads did not include this feature.

Technical specifications

• CPU: Intel 8021 / TI TMS1100 (on cartridge)
• Screen type and resolution: 16 × 16 pixel LCD
• Register width: 4 bit (TMS1100), 8 bit (8021)
• Processor speed: 100 kHz
• RAM (integrated into CPU): 64 bytes
• ROM: 2K (TMS1100), 1K (8021)
• Cartridge ROM: 2K (TMS1100), 1K (8021) masked (integrated into CPU; each game's CPU was different)
• Video Display Processor: LCD Custom Driver (made by Hughes)
• Sound: Piezo beeper
• Input: Twelve button keypad, one paddle
• Power requirements: One or two 9 volt batteries on earlier Microvision consoles, one 9 volt battery on later Microvision consoles
• Power Dissipation: 110 mW (TMS1100), 1 W (8021)

Games

In the United States, game cartridge plastic cases were beige in color. However, in Europe, these cases came in many different colors, and the games had numbers printed on their boxes. The console and its games in Europe were suitable for people aged 8 to 80 years old or 8 years old to adults. A total of 12 game titles were released.