Microvision
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| Manufacturer | Milton Bradley Company |
|---|---|
| Type | Handheld game console |
| Generation | Second generation |
| Release date | November 1979 |
| Discontinued | 1981 |
| Media | Microvision ROM cartridges |
| CPU | Intel 8021/TI TMS1100 (on cartridge) clocked at 100 kHz |
| Memory | 32 nibbles (16 bytes) RAM, 2K ROM |
| Display | 16 × 16 resolution |
| Power | 1× 9V battery (TMS1100 processors), 2× 9V battery (Intel 8021 processors) |
The Microvision is 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 $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 R&D1 Department stated that the Microvision gave birth to Nintendo Game & Watch after Nintendo designed around Microvision's limitations.
The processors for the first Microvision cartridges were made with both Intel 8021 (cross licensed by Signetics) 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 (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.
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.
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 (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.
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