The Successors: Evolution of Monochrome Handhelds after the Game Boy

When the Nintendo Game Boy was released in April/July, 1989 (Japan/North America), there was nothing like it on the market.  The Game Boy was the first programmable handheld system with sufficient capabilities to play games that were similar to the home consoles of its day.  The Game Boy was intended to be an inexpensive device, so it used a monochrome reflective green screen rather than a difficult-to-manufacture and power hungry backlit color screen like its main competitors, the Atari Lynx, Sega Game Gear, NEC Turbo Express and later the Sega Nomad.  Although the Game Boy definitively ruled over the color competing systems, dominating the market until its successor, the Game Boy Color, was released in October/November of 1998, that does not mean it was the only monochrome handheld game console on the market.  Early in its lifetime it had competitors from Taiwan which tried to take away some of its market with little success.  Later, more established companies tried to get on the monochrome bandwagon, only to find that lightning does not necessarily strike twice.  Recently, as retro style gameplay experiences have found a market in the age of the Nintendo Switch, we have seen at least one or two companies try their hand at a monochrome handheld.  In this article we will trace the evolution of the consoles that tried to compete with the Game Boy or invoke its success.

As I indicated above, the time period of the handheld competition can be roughly divided into three periods.  The first period, 1990-1994, saw the release of four consoles from Taiwan which used cartridges and superficially resembled the Game Boy both form and function.  The second period, 1995-1999, saw releases of consoles from more well-known companies in the US and Japan and were mostly technologically superior to the Game Boy.  The third period from 2000 onward saw monochrome systems as a novelty and tried to use their limited capabilities to sell consoles.

Before we begin with its competitors, let us briefly give an overview of the Game Boy.  The Game Boy used an Intel 8080/Zilog Z80 hybrid CPU designed by Sharp running at 1.048576MHz (Clock/4).  It has 8KiB of CPU RAM and 8KiB of Video RAM.  The audio and video hardware were designed by Nintendo and drew heavily on Nintendo's past experiences with the hardware it designed for the NES.  The screen had a resolution of 160x144 pixels, could display four shades of yellow-green, and the video hardware supported per-pixel X and Y axis scrolling, a window area for a non-scrolling status bar and video interrupts.  Its sound hardware consisted of two rectangle wave channel, a noise generation channel and a short-sample waveform playback channel (4 channels total) with stereo panning.  Most importantly, the graphics supported up to 40 8x8 pixel hardware sprites (or 20 8x16 pixels) on the screen with 10 sprites visible per line.

Physically, the Game Boy had the 2.6" diagonal monochrome "pea-soup green" screen, a single speaker, a D-pad with Start, Select, A and B buttons, a power switch, adjustment wheels for screen contrast and speaker/headphone volume, a Link Port for multiplayer functionality, a cartridge slot, a headphone jack, a DC power jack and a compartment for four AA batteries.  As the Game Boy was supported for most of its successor's lifespan by way of hybrid cartridges, Game Boy-compatible cartridges can range from 32KiB to 4MiB in size and many contained battery-backed RAM.  A memory bank controller must be used in all cartridges larger than 32KiB because the CPU can only address 32KiB of ROM at a time, a common limitation of 8-bit hardware consoles.

The First Period : The Taiwanese Efforts

Gamate, courtesy of arcadeartwork.org

Now let us turn to its monochrome competitors.  The first known competitor is the Gamate, developed by Bit Corp. and released in 1990.  Bit Corp. had already developed clones of the Atari 2600, ColecoVision and the Famicom, so it was well-versed in hardware design.  When Bit Corp. went bankrupt, UMC seemed to have taken over game development.  66 games have been confirmed for the system, 61 have no-intro dumps.

Kung Fu Fighter - Gamate

The Gamate used a 160x150 pixel screen, so it is slightly taller than the Game Boy's 160x144 screen.  Its audio capabilities were handled by a clone of the AY-3-8910 chip, so it could produce three channels of square wave or noise.  Its CPU uses the 6502 instruction set and runs at 2.2165MHz (Clock/2).  The system has 16KiB of Video RAM but only 1KiB of CPU RAM.  It has the same kind of button/port/dials as the Game Boy.  The Gamate's key weakness is that it had no support for hardware sprites, so games tend to run slowly and flickery.  Game range from 32KiB to 512KiB in size.  Its BIOS is 4KiB and the games have some weak copy protection built into them.  

SuperVision (all photos credit Wikipedia unless otherwise stated)

The second competitor is the SuperVision, designed by Watara and released in 1992.  This console comes in two form factors, one that has a uniform plastic body like the Game Boy and the other with an adjustable screen angle with a flexible hinged area between the screen and the game controls.  It was known as the QuickShot SuperVision in many parts of the world but was also known by other names such the SV-100 depending on the region in which it was released.  There were 68 single game and three multi game cartridges released for the system according to no-intro.  It was the most relatively successful console which originated from Taiwan, having a TV show in the UK called Bad Influence which used the handheld and it was cheaper than the Game Boy.

Journey to the West - SuperVision

The SuperVision used a 160x160 screen and a 65C02 CPU running at approximately 4MHz.  It has 8KiB of CPU RAM and 8KiB of Video RAM.  Audio hardware is very similar to the Game Boy's, it has two rectangle waves, a noise generator and a waveform sample playback channel.  Like the Gamate, while it can scroll the screen horizontally and vertically on a per-line basis, the Supervision has no sprite system, so it relies on the CPU to brute force the graphics.  Games were either 32KiB or 64KiB, with one using 512KiB.  It was not always enough to prevent slowdown and flicker as shown in games like Journey to the West.

Mega Duck

1993 saw the release of the Mega Duck, a.k.a. the Cougar Boy, designed by Welback/Timlex.  The Mega Duck is a Game Boy clone, it contains the same hardware as a Game Boy and shares the exact same capabilities.  It is not compatible with Game Boy software because its cartridge slot uses 36 pins to the Game Boy's 32 pins and the Mega Duck rearranged the memory and registers to break compatibility with Game Boy games, presumably to fend off claims of patent infringement.  

Snake Roy - Mega Duck

Almost all of the games on the 37 known cartridges were developed by Sachen/Commin, and almost all of them were re-released on the Game Boy in Sachen's unlicensed 4-in-1 cartridges.  Mega Duck games ranged from 32KiB to 128KiB in size.

Impel Game Master, courtesy of lostmediawiki.org

In terms of weirdness, the Hartung Game Master, also released under several names such as the Systema 2000, takes the prize for this period.  The release date of this console is not known with any real specificity.  Uniquely for this time period, it was released by a German company rather than a Taiwanese company.  It used a 61x64 display capable of only displaying 2 shades of monochrome, which really makes for blocky graphics.  Its audio was similarly crude, sounding like a PC speaker.  All this is driven by an NEC uPD78C11 microcontroller running at 6MHz, which only contains 256 bytes of RAM and a 4KiB BIOS.  There is no Link Port equivalent on this console, unlike the Gamate and SuperVision.  Cheaply built, it only had a library of 18 game cartridges.  Of the 11 whose dumps I have, they range in size from 8KiB to 32KiB.

Pin Ball - Game Master

All first period monochrome handhelds share a common feature, obscurity.  While they all made it to the west, they stood no chance of having any meaningful success against the Nintendo juggernaut and the color alternatives.  While they could compete on price, they could not compete on the quantity or quality of games or the marketing and distribution behind the systems that played those games.  Three out of the four had a crippling flaw compared to the Game Boy without offering significant advantages.  The brute force CPU method of graphics began here, but would continue onwards.  

The Second Period : The Big Boys Come to Play

game.com

For the next period, we start with Tiger Electronics, which released the game.com on September 12, 1997.  The game.com was so named to cash in on its connection to the internet, which was still something of a novelty at the time.  The system came with Solitaire built in and had 20 cartridges released for the system.  The cartridge booted to a menu with six icons: cartridge, phone book, calendar, calculator, high score and solitaire.  It thus functioned not unlike a PDA.  It had a touch screen and with an internet cartridge and dial up modem, could support a text-based Internet experience.  The internet was accessed via the Internet Cartridge and game high scores could be uploaded via the Web Link cartridge.  The Internet required connection to a hardware 14.4K modem, which tethered the experience and was not popular in the days before Wi-Fi.  

Resident Evil 2 - game.com

The system was designed around a Sharp SM8521 running at 10MHz.  The Sharp chip contained its own graphics and sound hardware.  The screen resolution was 200x160 at 4 shades of gray.  The audio was decent with two channels of short-sample (4-bit x 32 samples) wavetable synthesis, a noise generator and an 8-bit PWM digitized channel.  The video hardware did not provide sprites, so games tended to be choppy, flickery, slow affairs.  Cartridges can be hot-swapped, something rather unique for the time.  Games range from 256KiB to 2MiB.

The system has many unusual features for an 8-bit system.  It has a holder for the touchpad stylus.  The touch screen aspect was not pixel based but area based, with a grid of 12 x 10 distinct areas.  It has four face buttons, A-D, and buttons for Menu, Sound and Pause.  The console has a backup CR2032 battery for the date/time settings, two cartridge ports and a reset button tucked away.  The two cartridge port was originally intended to allow a game to access the internet via the other cartridge but no game supported this feature.  The game.com Pocket Pro was a slim-line version of the game.com that only used two AA batteries, ditched the 2nd cartridge port and the Sound button but did provide a toggle button for front lighting the screen, which is almost (Game Boy Light sported a backlight) unique for monochrome handhelds.  

Neo Geo Pocket

SNK, maker of the Neo Geo Arcade System, sought to compete with the aging Game Boy by releasing a "Game Boy killer", the Neo Geo Pocket.  The Neo Geo Pocket was unfortunately the victim of timing.  The Neo Geo Pocket was released in Japan on October 28, 1998.  The tragic bit is that Nintendo's Game Boy Color had already been released one week before on October 21, making the monochrome SNK system obsolete on launch day.  As a result, only 10 games were released for the system and the system was not released in North America.  SNK did a really quick about face and released a backwards-compatible color version of the console five months later on March 16, 1999.  The color console, the Neo Geo Pocket Color, supported 83 games   Owners of the monochrome console were not left completely in the cold, as 49 of those 83 NGPC games had compatibility with the monochrome systems with color graphics being displayed in monochrome shades.  In total, 59 cartridges can be run on the monochrome system.

Baseball Stars Pro - Neo Geo Pocket

NEC really sought to compete with the Game Boy and presented specifications which did not try to cut every corner possible to make a device which could technically play games.  The Neo Geo Pocket utilized the Toshiba TLCS-900H CPU, a 16/32-bit hybrid CPU running at 6.144MHz.  It's screen used a 160x152 resolution and supported 20 shades of gray.  It had a Z80 CPU running at 3.072MHz intended as an audio coprocessor and utilized the 4-channel SN76489 sound source.  There was 12KiB of RAM for the main CPU, 4KiB shared with the coprocessor, 4KiB for tilemaps and 8KiB for character RAM.  It supported a sprite engine of up to 64 sprites per screen and two background layers which could scroll independently.  Game size ranged from 512KiB to 2MiB.  

The console ran on two AA batteries and also used a CR2032 for keeping the date/time and keeping backup memory.  There is a 64KiB BIOS which shows the date and time, provide horoscopes based on one's date of birth and can change the language of a game if the game supports multiple languages. Even without a cartridge inserted you could still do something with the NGP.  Physically the Neo Geo Pocket only offered a single Option button.  It did not use a traditional D-pad but a clicky digital thumbstick designed for fighting games.  

WonderSwan

The Bandai Wonderswan, released on March 4, 1999 by Bandai, has a legitimate claim of being the "true Game Boy successor", having been designed by Gunpei Yokoi, who designed the Game Boy.  Of course, while Bandai knew their system was much more powerful than the Game Boy, like the Neo Geo Pocket it was obsolete the moment of its release.  Nonetheless Bandai stuck with their monochrome system for much longer than SNK did with its, not releasing the WonderSwan Color until December 9, 2000.  Bandai and its third parties released 109 monochrome games and 18 backwards compatible color games, bringing the total supported cartridges on the monochrome system to 127.  The WonderSwan therefore comes the closest of all monochrome cartridge systems to matching the size of the Game Boy's library.  Unfortunately, none of the WonderSwans were ever released outside of Japan.

Gunpey - Wonderswan

Physically, the WonderSwan is among the most unique of these devices.  The system has the equivalent of two D-pads as well as A and B buttons.  Combined with a widescreen resolution of 224x144 with 8 shades of color, this allowed the WonderSwan to play vertically oriented games not unlike the Atari Lynx. It only has a Start button and instead of a volume wheel for the speaker, it has a Sound button with three selectable audio levels, quiet, loud and off.  The WonderSwan is powered off one AA battery, something of a marvel for its time.  The battery holder and electrical contacts are molded into the plastic cover, so you will need a replacement if yours does not come with one.  The WonderSwan used the NEC V30 16-bit CPU running at 3.072MHz with 16KiB of RAM shared between the CPU and the video hardware.  It supports two independent background layers and up to 128 sprites per frame and 32 sprites per line.  It supports 4-channels of short-sample (4-bit x 32 samples) wavetable synthesis.  Games came from 512KiB to 4MiB.

The WonderSwan had an accessory called the WonderWave which could communicate via IR with the Sony PocketStation.  The WonderGate permitted access to the Internet e-mail and browsing as well as being supported by some games for downloadable content via certain mobile phones.  There is no headphone jack, headphones are supported via the "extension port", this console's version of a link port with an adapter.  There is no DC adapter port, the battery is the only way to power this system.

Both SNK and Bandai had real third-party support and were able to produce many playable games for their systems whereas Tiger just had licenses but terrible hardware unworthy of those licenses.  Sega,  Capcom, Data East and Namco each had a monochrome-compatible game for the NGP, but most of the NGP's monochrome gaming came from SNK.  Bandai was more successful, attracting Data East, Jaleco, Koei, Konami, Sammy, Squaresoft, Sunsoft and Taito to its platform.  All these publishers except for Sega and Squaresoft published on Nintendo's handheld platforms, but both would be publishing for the GBA by 2001.

Nintendo's Other Monochrome Portables

During the Game Boy's lifetime, Nintendo released two other monochrome "portable" consoles, in a way competing with itself.  The first was the Virtual Boy, released on July 15, 1995 and which was technically a portable console in that it could be powered by six AA batteries.  However, the headset was large and bulky and sat on a stand.  The controller was a separate wired device, so its portability was more of a nominal feature than a practical one.  It was monochrome because it used red-only colors, but the unit caused eyestrain and headaches.  However, as is well known, the Virtual Boy was the first major bona fide flop by Nintendo since the 1970s and only 19 games were released for the console.

Pokemon Mini

The second monochrome portable console Nintendo released that was not a Game Boy was the tiny Pokemon Mini.  While it looked like a Tamagotchi keychain, it did have interchangeable cartridges and a microprocessor.  A two-shade screen consisting of 96x64 pixels provided the graphics and a speaker fired out from the back of the unit.  The screen was non-backlit and the device ran on a single AAA battery.  The device has a D-pad and A and B buttons as well as a power button, a recessed reset button and a C shoulder button.  There is an IR window on the top of the device and the device supports a built-in RTC and it had a motion sensor and a rumble feature.  

Pokemon Tetris - Pokemon Mini

The Pokemon Mini's CPU is a 4MHz Seiko S1C88 with 4KiB of BIOS ROM and 4KiB of RAM, which is shared between CPU and video.  The sound is a single square wave with three volume levels.  The video is capable of smooth X/Y scrolling and also can display 24 16x16 sprites.  It sold some units due to the novelty of its size and its Pokemon connection, but it just was too limited to be taken seriously as a games console, even though it is capable of playing decent games.  Only 10 game cartridges were released and all games seem to use 512KiB ROMs.

The Third Period : Handhelds as Novelty Consoles

GameKing Model 1

Edging out the Game Master in terms of weirdness, the GameKing was released in 2003 by Timetop in Hong Kong and appears to have been targeted toward the Chinese market  The GameKing is notable for having a 48x32 pixel screen with 4 levels of grayscale, which was prehistoric compared to the Game Boy Advance.  The graphics hardware is capable of handling LCDs of Game Boy-levels of pixel density.  Audio is 8-bit PWM, usually at 46.9KHz and two samples can play back at the same time.  The audio hardware has the ability to generate square waves and noise, but these functions went generally unused.  All-in-all, the audio hardware is almost on par with a GBA.  It has a 512KiB BIOS which also contains three built-in games.  The GameKing uses a 65C02 running at 6MHz, which is more than capable of brute-forcing the graphics on such a low-resolution screen at decent speed.

Racing Car - GameKing

The GameKing uses two AAA batteries and is rather power efficient.  It looks like a GBA and has shoulder buttons but they do not connect to anything.  It has cut outs for two speakers but only one speaker is included.  It has a tiny hardware reset button, which is unusual on handheld game consoles.  Most games implemented a "soft reset" via a controller button combination like Start + Select + A + B.  The GameKing II uses three AAA batteries, but one is only required for the audio amplifier and screen backlight and it can work with two AAAs if you are willing to sacrifice those features.  The GameKing III is a backwards-compatible color system but seems to retain the blocky 48x32 resolution.  Despite its late release, 25 games were released for the system.  

Up to this point, the history of monochrome handheld game consoles discussed in the blog entry that are not the Game Boy has largely been a history of obscurity and failure.  Except for the WonderSwan and Neo Geo Pocket, other systems just could not compete with the Game Boy.  The Game Boy had many, many games, recognizable franchises, a diverse library, quality developers, a hit pack-in game, a competitive price point, strong marketing and just enough power to play fast-paced 8-bit games.  The Game Master and the game.com made the mistake of relying on generic microcontrollers that were not designed for games.  Along with the game.com, the SuperVision and the Gamate both suffered from video hardware that did not support sprites, which is essential to fast 8-bit gameplay.  The Mega Duck failed because its hardware was too close to that of the Game Boy and the compromises that had to be made to obscure that fact from casual inspection limited the library to games of dubious quality.

PlayDate (courtesy of play.date)

Finally we come to the present day with the release of the PlayDate from Panic on April 18, 2022.  This console was first announced on May 22, 2019.  The console uses an STM32F746 ARM Cotrex M7 System on a Chip CPU running at 168MHz.  The CPU has 32KiB of L1 cache and access to 16MiB of RAM.  The display uses a 400x240 resolution with 2-shades, reminiscent of an original Apple Macintosh.  The video hardware on the chip has some SVGA-style draw and fill functions but I do not know if they are being utilized by the programming tools. It uses an internal battery charged by a USB Type-C charging port and has a Power/Sleep button.  Audio is via a mono speaker but there is a headphone jack.  

The controls on the PlayDate separate it from its predecessors.  It has a D-pad, B and A buttons and a Home button but it also has a "crank" controller.  The crank allows for analog input not unlike a rotary dial and has a divot in the case where the handle can rest .  It also presents a 3-axis accelerometer and a microphone next to the headphone jack.  Bluetooth support has been mentioned for a future firmware update.  From reviews the only major hardware complaint about the PlayDate has been about the non-backlit screen.  Even without a backlight, the screen should be far easier to use in ambient light than any other monochrome system mentioned in this article.

Adding games to the system requires downloading from the internet and the device supports Wi-Fi 2.4G 802.11b/g/n.  Officially, games are being released in "seasons", with Season 1 containing 24 games, being released two per week.  Games must be saved to the 4GiB Flash chip in the PlayDate.  You can also load and develop games via the USB-C port. The PlayDate has an open development environment, independent developers can write games using the development provided Lua and C APIs.  More casual developers can use Pulp, a web-based game creation interface.  

In the third generation we see that custom audio/video hardware is no longer the focus of these designs.  Instead, generic but power-efficient SoCs capable of driving an LCD have been used.  In these cases the systems are not overtaxed with having to output high resolution graphics, thus they can brute force fast gameplay.  And as they are relatively primitive devices compared to the competition, they should have comparatively long battery life.