Microvision
Encyclopedia
The Microvision was the very first handheld game console that used interchangeable cartridges. It was released by the Milton Bradley Company
in November . 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 .
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.
damage, and keypad destruction.
was primitive by today's standards. Poor sealing and impurities introduced during manufacture has resulted in the condition known as screen rot. The liquid crystal spontaneously leaks and permanently darkens, resulting in a game unit that still plays but is unable to properly draw the screen. While extreme heat (such as resulting from leaving the unit in the sun) can instantly destroy the screen, there is nothing that can be done to prevent screen rot in most Microvisions.
protection and is directly connected to the copper pins which normally connect the cartridge to the Microvision unit. If the user opens the protective sliding door that covers the pins, the processor can be exposed to any electric charge the user has built up. If the user has built up a substantial charge, the discharge can jump around the door's edge or pass through the door itself (dielectric breakdown). The low-voltage integrated circuit
inside the cartridge is extremely ESD sensitive, and can be destroyed by an event of only a few dozen volts which cannot even be felt by the person, delivering a fatal shock to the game unit. This phenomenon was described in detail by John Elder Robison
(a former Milton Bradley engineer) in his book Look Me in the Eye
.
, with the switches buried under a thick layer of flexible plastic. To align the user's fingers with the hidden buttons, the cartridges had cutouts in their bottom (over the keypad). As different games required different button functions, the cutouts were covered with a thin printed piece of plastic, which identified the buttons' functions in that game. The problem with this design is that pressing on the buttons stretched the printed plastic, resulting in the thin material stretching and eventually tearing. Having fingernails exacerbated the condition. Many of the initial games were programmed to give feedback of the keypress when the key was released instead of when the key was pressed. As a result, users may press on the keypad harder because they are not being provided with any feedback that the key has been pressed. This resulted from a keypad used for prototyping being different from the production keypad; the prototyping keypad had tactile feedback upon key pressing that the production units lacked.
Milton Bradley Company
The Milton Bradley Company is an American game company established by Milton Bradley in Springfield, Massachusetts, in 1860. In 1920, it absorbed the game production of McLoughlin Brothers, formerly the largest game manufacturer in the United States, and in 1987, it purchased Selchow and Righter,...
in November . The Microvision was designed by Jay Smith
Smith Engineering
Smith Engineering/Western Technologies was a videogame company started by Jay Smith, an engineer who was previously an employee at Mattel. The company proposed and developed the Vectrex gaming system for GCE, which was subsequently purchased by Milton Bradley...
, the engineer who would later design the Vectrex
Vectrex
The Vectrex is a vector display-based video game console that was developed by Western Technologies/Smith Engineering. It was licensed and distributed first by General Consumer Electric , and then by Milton Bradley Company after their purchase of GCE...
gaming console. The Microvision's combination of portability and a cartridge-based system led to moderate success, with Smith Engineering
Smith Engineering
Smith Engineering/Western Technologies was a videogame company started by Jay Smith, an engineer who was previously an employee at Mattel. The company proposed and developed the Vectrex gaming system for GCE, which was subsequently purchased by Milton Bradley...
grossing $8 million in the first year of the system's release. The handheld also appeared in the movie Friday the 13th Part 2
Friday the 13th Part 2
Friday the 13th Part II is a 1981 slasher film directed by Steve Miner, who also directed its sequel, Friday the 13th Part III and several other popular horror films. A sequel to Friday the 13th , it is the second film in the Friday the 13th film series. It was a moderate box-office hit, opening on...
. However, very few cartridges, a small screen, and a lack of support from established home video game companies led to its demise in .
Production
The first Microvision cartridges were made with both Intel 8021 and Texas InstrumentsTexas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
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.
Problems
Microvision units and cartridges are now somewhat rare. Those that are still in existence are susceptible to three main problems: "screen rot," ESDElectrostatic discharge
Electrostatic discharge is a serious issue in solid state electronics, such as integrated circuits. Integrated circuits are made from semiconductor materials such as silicon and insulating materials such as silicon dioxide...
damage, and keypad destruction.
Screen rot
The manufacturing process used to create the Microvision's LCDLiquid crystal display
A liquid crystal display is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals . LCs do not emit light directly....
was primitive by today's standards. Poor sealing and impurities introduced during manufacture has resulted in the condition known as screen rot. The liquid crystal spontaneously leaks and permanently darkens, resulting in a game unit that still plays but is unable to properly draw the screen. While extreme heat (such as resulting from leaving the unit in the sun) can instantly destroy the screen, there is nothing that can be done to prevent screen rot in most Microvisions.
ESD damage
A major design problem involves the fact that the microprocessor (which is inside the top of each cartridge) lacks ESDElectrostatic discharge
Electrostatic discharge is a serious issue in solid state electronics, such as integrated circuits. Integrated circuits are made from semiconductor materials such as silicon and insulating materials such as silicon dioxide...
protection and is directly connected to the copper pins which normally connect the cartridge to the Microvision unit. If the user opens the protective sliding door that covers the pins, the processor can be exposed to any electric charge the user has built up. If the user has built up a substantial charge, the discharge can jump around the door's edge or pass through the door itself (dielectric breakdown). The low-voltage integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
inside the cartridge is extremely ESD sensitive, and can be destroyed by an event of only a few dozen volts which cannot even be felt by the person, delivering a fatal shock to the game unit. This phenomenon was described in detail by John Elder Robison
John Elder Robison
John Elder Robison is the author of the 2007 memoir Look Me in the Eye, detailing his life living with Asperger syndrome. He is the elder brother of memoirist Augusten Burroughs, who also wrote about his childhood in the memoir Running with Scissors.-Life:Robison was born in Athens, Georgia while...
(a former Milton Bradley engineer) in his book Look Me in the Eye
Look Me in the Eye
Look Me in the Eye: My Life with Asperger's is a New York Times bestseller by John Elder Robison, chronicling the author's life with Asperger syndrome and tough times growing up.-Story:...
.
Keypad destruction
Instead of having buttons on a separate controller, the Microvision unit had a twelve-button keypadKeypad
A keypad is a set of buttons arranged in a block or "pad" which usually bear digits, symbols and usually a complete set of alphabetical letters. If it mostly contains numbers then it can also be called a numeric keypad...
, with the switches buried under a thick layer of flexible plastic. To align the user's fingers with the hidden buttons, the cartridges had cutouts in their bottom (over the keypad). As different games required different button functions, the cutouts were covered with a thin printed piece of plastic, which identified the buttons' functions in that game. The problem with this design is that pressing on the buttons stretched the printed plastic, resulting in the thin material stretching and eventually tearing. Having fingernails exacerbated the condition. Many of the initial games were programmed to give feedback of the keypress when the key was released instead of when the key was pressed. As a result, users may press on the keypad harder because they are not being provided with any feedback that the key has been pressed. This resulted from a keypad used for prototyping being different from the production keypad; the prototyping keypad had tactile feedback upon key pressing that the production units lacked.
Technical specifications
- CPUCentral processing unitThe central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
: 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: 32 nybbles (16 8-bit bytes, integrated into CPU)
- ROM: 2K
- Cartridge ROM: 2K masked (integrated into CPU; each game's CPU was different)
- Video Display Processor: Custom (made by Hughes)
- Sound: Piezo beeper
- Input: Twelve button keypad, one paddlePaddle (game controller)A paddle is a game controller with a round wheel and one or more fire buttons, where the wheel is typically used to control movement of the player object along one axis of the video screen...
- Power requirements: One 9 volt battery (TMS1100 processors), Two 9 volt batteries (Intel 8021 processors)
Games
- 1979
- Block BusterBlock Buster (Microvision)Block Buster is a Microvision video game. It was originally packaged with the Microvision.- Gameplay :Block Buster plays like Atari's arcade game Breakout. Using the Microvision's paddle, a ball bounces around the screen while smashing bricks. When all the bricks are smashed, all the bricks come...
- Bowling
- Connect Four
- Mindbuster
- PinballPinball (Microvision)Pinball is a Microvision game. Pinball seems like a Block Buster hack because of the way the ball is hit with a paddle and not flippers....
- Star Trek: Phaser StrikeStar Trek: Phaser StrikeStar Trek: Phaser Strike is a Microvision game published by Milton Bradley in 1979, released at the same time as the film Star Trek: The Motion Picture. In the game, the player must destroy Klingon ships with phaser banks located at the bottom of the screen. The Star Trek name was later dropped...
(later just Phaser Strike) - Vegas Slots
- Block Buster
- 1980
- Baseball
- Sea Duel
- 1981
- Alien Raiders
- Cosmic Hunter
- 1982
- Barrage (Not released - no known prototypes)
- Super Blockbuster (Released only in Europe)