Microvision


The Microvision is the first handheld game console that used interchangeable ROM cartridges and is therefore programmable. It was released by the Milton Bradley Company in November 1979 for a retail price of $49.99.
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 $15 million in the first year of the system's release. However, very few cartridges, a small screen, and a lack of support from established home video game companies led to its demise in 1981. According to Satoru Okada, the former head of Nintendo's R&D1 Department, the Microvision gave birth to the Game & Watch after Nintendo designed around Microvision's limitations.

Production

Unlike most later consoles, the Microvision did not contain an onboard processor. Instead, each game included its own processor contained within the removable cartridge. This meant that the console itself effectively consisted of the controls, LCD panel and LCD controller.
The processors for 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 including reprogramming the games that were originally programmed for the 8021 processor. 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 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 put most of its marketing muscle at the time behind the tabletop Vectrex system, contributing to the Microvision's mediocre performance in the market.

Problems

Microvision units and cartridges are now somewhat rare. Those that are still in existence are susceptible to three main problems: "screen rot," ESD damage, and keypad destruction.

Screen rot

The manufacturing process used to create the Microvision's LCD was primitive by modern 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 which can instantly destroy the screen can be avoided, there is nothing that can be done to prevent screen rot in most Microvision systems.

ESD damage

A major design problem on early units involves the fact that the microprocessor lacks ESD 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. 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 in his book Look Me in the Eye; Robinson described the issue as having been a significant enough issue during the 1979 holiday season that it resulted in significant panic among Milton Bradley staff and required extensive modifications to both later Microvision units and Microvision factories to better dispel stray static charges.

Keypad destruction

The Microvision unit had a twelve-button 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. 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 long 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

While the game cartridge plastic cases were beige colored in the USA, in Europe they came in a variety of different colors, and the games were numbered on the Box. The age range in Europe for the console and its games was from 8 to 80 years old or 8 to Adult.
There were titles known to have been released.
#US TitleOverseas TitlesGame Number Release DateMicroprocessor/s
1Block BusterBlock Buster
Block Buster
Block Buster
Block Buster
Casse Brique		1
1
1
1
1		TI MP3496-N1 or TI MP3450A
2BowlingBowling
Bowling
Bowling
Bowling
Bowling		2
2
2
2
2		TI MP3475NLL
3Connect FourConnect 4
4 Gewinnt
Veir Op'n Rij
Forza 4
Puissance 4		5
5
5
5
5		Signetics Intel 8021
4PinballPinball
Pinball
Flipper
Flipper
Flipper		4
4
4
4
4		TI MP3455NLL
5MindbusterN/AN/ATI MP3457NLL
6'
Shooting Star
Shooting Star
Shooting Star
Shooting Star
Shooting Star		3
3
3
3
3		TI MP3545'
7Vegas SlotsN/AN/A?
8BaseballN/AN/A?
9Sea DuelSea Duel
See-Duell
Duel
Duello Sul Mare
Bataille Navale 		6
6
6
6
6		?
10Alien RaidersSpace Blitz
Blitz
Blitz
Blitz
Blitz		7
7
7
7
7		?
11Cosmic HunterN/AN/A?
12N/ASuper Block Buster
Super Blockbuster
Super Block Buster
Super Casse Brique 		8
8
8
8		?
13Barrage''??Unreleased
?

In popular culture

The Microvision was featured in Friday the 13th Part 2.