MSX is a set of rules for home computers that were created to help different companies make compatible machines. ASCII Corporation announced MSX on June 16, 1983. Microsoft first thought of the idea as a product for Japan, and Kazuhiko Nishi, a leader at ASCII Corporation, helped promote it. Microsoft and Nishi wanted to create one standard for home computers, similar to how the VHS standard helped unify video tape machines. The first MSX computer sold to the public was the Mitsubishi ML-8000, released on October 21, 1983, which marked the official start of the MSX system.

MSX computers became popular in Japan and other countries. Different sources report different numbers of units sold. One source says 9 million MSX computers were sold worldwide, with 7 million in Japan. Kazuhiko Nishi, the founder of ASCII Corporation, says 3 million were sold in Japan and 1 million outside of Japan. Even though Microsoft was involved, few MSX computers were sold in the United States.

The meaning of the name "MSX" is not certain. In 2001, Nishi said some people thought it came from "Microsoft Extended," which refers to a version of BASIC software included in MSX computers. Others believed it stood for "Matsushita-Sony." Nishi explained that the team originally thought of it as "Machines with Software eXchangeability." Later, he said the name might have been inspired by the MX missile. In his 2020 book, Nishi wrote that the name should have three letters, like VHS. He believed "MSX" worked because it meant "the next step for Microsoft" and included the first letters of Matsushita (now Panasonic) and Sony.

Before Nintendo’s Family Computer became popular, many major Japanese game companies, such as Konami and Hudson Soft, created games for the MSX platform. The first two games in the Metal Gear series were originally released for MSX computers.

History

In the early 1980s, many home computers made in Japan, such as the NEC PC-6001 and PC-8000 series, Fujitsu’s FM-7 and FM-8, and Hitachi’s Basic Master, included a version of Microsoft BASIC built into their internal memory. These computers had different hardware designs and versions of BASIC, which made them unable to work together. Other Japanese companies, like Panasonic, Canon, Casio, Yamaha, Pioneer, and Sanyo, were trying to find ways to enter the home computer market.

Major Japanese electronics companies started selling computers in the 1960s. Panasonic, then called Matsushita Electric Industrial, also made mainframe computers. After Japan’s economy slowed down following the 1964 Summer Olympics, Panasonic decided to stop making computers and focus on home appliances. This decision helped the company grow into one of the largest electronics firms. In the late 1970s, Panasonic explored new business areas and saw potential in the rise of microcomputers. A distributor named Yamagata National suggested to Panasonic’s president, Toshihiko Yamashita, that the company should create a personal computer.

Yamashita asked his vice president, Shunkichi Kisaka, to develop a computer. Kisaka then asked Kazuyasu Maeda from Matsushita R&D Center to help. Maeda requested assistance from Nishi, who had connections with Maeda through a university and a seminar held by NEC. At the same time, Spectravideo asked Microsoft for software for their new computer. Nishi traveled to Hong Kong to meet Spectravideo and suggested improvements to their design. Spectravideo’s president, Harry Fox, agreed to Nishi’s ideas. Nishi wanted to create a standard for home computers, and Maeda supported the plan. Nishi aimed to involve Panasonic and Sony in the project. Sony’s Nobuyuki Idei agreed to cooperate with Panasonic because Sony’s first computer, the SMC-70, struggled in the market. Maeda also wanted to include NEC, but NEC chose to work alone.

Nishi proposed the MSX standard to create a single standard for home computers. Inspired by the success of VHS, a standard for video recorders, many companies in Japan and other countries, including GoldStar, Philips, and Spectravideo, built and promoted MSX computers. Any hardware or software with the MSX logo could work with other MSX products. The expansion cartridge format was part of the standard, meaning any MSX game or expansion cartridge would work in any MSX computer.

The MSX standard was based on the Spectravideo SV-328 computer. It used common parts, such as a 3.58 MHz Zilog Z80 CPU, a Texas Instruments TMS9918 graphics chip with 16 KB of video memory, a sound chip from General Instrument, and an Intel 8255 chip for input/output tasks. These parts were also used in other computers and game consoles, like the ColecoVision and Sega SG-1000. To lower costs, many MSX models used a custom chip called “MSX-Engine,” which combined several components. However, most MSX systems used professional keyboards, which made them more expensive than the original SV-328. These features, along with Microsoft’s MSX BASIC, made the MSX a strong but costly option for home computers.

On June 27, 1983, the MSX was officially announced at a press conference. Many companies pledged to support the standard. These companies avoided the highly competitive U.S. market, where a price war led by Commodore was happening. Only Spectravideo and Yamaha briefly sold MSX computers in the U.S. Spectravideo’s MSX had little success, and Yamaha’s CX5M model, designed for MIDI equipment, was promoted more as a music tool than a computer.

The MSX standard had four generations. The first three—MSX (1983), MSX2 (1985), and MSX2+ (1988)—were 8-bit computers using the Z80 microprocessor. The MSX2+ was only sold in Japan. A new MSX3 was planned for 1990 but faced delays due to problems with a graphics chip designed by Yamaha. Instead, the MSX TurboR was released, using a new 16-bit R800 processor. However, some advanced features were disabled.

Problems with ASCII Corporation and Microsoft’s partnership also caused issues. In 1986, Microsoft ended its partnership with Nishi, claiming he owed the company over $500,000. Microsoft then opened a branch in Japan. ASCII Corporation continued to operate. Nishi’s impulsive decisions and spending habits, such as spending $1 million on a mechanical dinosaur for advertising, led to the break with Microsoft. Nishi and Bill Gates had a difficult relationship, though they occasionally speak now.

In 1991, two co-founders of ASCII, Akio Gunji and Keiichiro Tsukamoto, suddenly resigned, claiming they could not keep up with Nishi’s rapid expansion. Nishi said at a press conference that he was moving too quickly for them to follow.

Like the MSX2+, the MSX TurboR was only sold in Japan. By 1990, only Panasonic was making MSX computers. Its first model, the FS-A1ST, had moderate success, but the upgraded FS-A1GT sold poorly due to its high price of 99,800 yen (about $740 at the time). Production of the TurboR ended in 1993 when Panasonic focused on the 3DO system. The graphics chip for MSX3 was finally delivered in 1992, but the market had already moved on. Yamaha later repurposed the chip for PC VGA cards with limited success.

In Japan, South Korea, Argentina, and Brazil, the MSX was the most popular home computer in the 1980s. It was also widely used in parts of Europe, especially the Netherlands and Spain. In some Arab countries, the Soviet Union,

Similar systems

The MSX system was most similar to the Spectravideo SV-328 home computer. Spectravideo claimed its system was "MSX compatible" in advertisements before MSX systems were officially released, but it was not fully compatible with them. This situation led to a brief type of software modification. Since MSX games could not be played on the SV-328, users of the SV-328 created methods to change the games so they would work on their system. In most cases, this involved copying the MSX BIOS from a tape or floppy disk to the SV-328. Later, Spectravideo released the SVI-728, which fully followed the MSX standard.

The Sega SG-1000, Memotech MTX, Tatung Einstein, and ColecoVision share many features with the MSX1 standard but are not fully compatible with it. Moving games between these systems is somewhat simple, but it is difficult due to limited memory and different sound hardware. Because of the limited memory, many RAM adapters were made and sold in places like Taiwan to help with the process. It was also common to move games from the ZX Spectrum to the MSX because both systems used the same CPU, the Spectrum 128 had the same sound chip, and the ZX Spectrum's graphics could be easily recreated using the MSX's screen-2 mode.

Several Roland S-series audio and music devices, such as keyboards and synthesizers, are based on the MSX operating system. These include early models with 12-bit sample resolution, like the S-50, S-330, S-550, W-30, and later models with 16-bit sample resolution, such as the S-770, S-750, SP-700, and S-760. Most of these models had (or could be upgraded with) color video outputs to connect to monitors and included ports for MSX-compatible mice.

Localization

By default, MSX computers use a pre-set character set and keyboard code system. While MSX machines are fully compatible with application software at the firmware (BIOS) level, small differences in hardware can cause problems if the BIOS is replaced with one from another computer. This might lead to incorrect keyboard behavior in software programs.

In 2011, AGE Labs created the Language Pack firmware to allow each MSX model to support multiple language settings. In the GR8BIT kit from AGE Labs, the Language Pack is used by default instead of the Kanji-ROM. This feature lets users choose between Japanese, Russian, International, and Portuguese language settings at startup. It also allows users to change the language during operation using the new LANG command in BASIC. The selected language setting is saved in unused memory space within the RTC NVRAM.

Developments for MSX

The SCC chip was developed by the Japanese video game company Konami in February 1986. At that time, Konami's development teams were working on the MSX, Famicom, and arcade games. Before creating the SCC chip, Konami used a device called the programmable sound generator (PSG), which could only produce three types of sounds. Because there were no sound ports available, Konami's MSX team member Kazuhiko Uehara, who had worked on earlier projects, used the cartridge slot of the MSX system as an extra source of sound. After sharing this idea with Konami's president, Kagemasa Kozuki, the company began developing the SCC chip with help from Toshiba.

Before the SCC chip was created, Konami was reportedly unhappy because the MSX system did not have the same sound quality as Nintendo's Famicom, even though both systems were from the same generation of consoles. The SCC chip added five new sound channels, each with an on/off switch, to the three already provided by the PSG, allowing for more complex sound production. The chip also had separate memory mapping. Although the SCC was originally made for the game F-1 Spirit, scheduling changes caused Nemesis 2 to be released first, becoming the first video game to use the chip. In the November 1987 issue of the Konami Software Club newsletter, the SCC chip was officially named the Konami Large Scale Integration Sound Creative Chip. Between 1987 and 1989, fifteen MSX games used the SCC chip, including Nemesis 2, F-1 Spirit, The Way to Formula 1, Salamander, Parodius, King's Valley II, Contra, Nemesis 3: The Eve of Destruction, Metal Gear 2: Solid Snake, Space Manbow, and Quarth.

Games

Several well-known video game series began on the MSX platform:

• Antarctic Adventure and Penguin Adventure
• Aleste and Zanac (Zanac was created and released at the same time as the original FDS version)
• Bomberman
• Eggerland
• Metal Gear
• Parodius
• Puyo Puyo (released alongside the FDS version)

Other games had different versions on the MSX, including some that were only available on this system or significantly changed versions of games from other platforms:

• Castlevania (called Vampire Killer in Europe)
• Contra
• Dragon Quest
• Dragon Slayer
• Final Fantasy
• Gradius (Nemesis)
• R-Type
• Wizardry
• Xak
• Xevious: Fardraut Saga

Legacy

In 2001, Kazuhiko Nishi started a revival of the MSX computer using an official emulator named MSXPLAYer. This is the only official MSX emulator because all MSX copyrights are managed by the MSX Association. In 2004, a Dutch company named Bazix became the European representative for the MSX Association, handling questions about MSX trademarks, copyrights, and licensing. On October 17, 2006, Bazix launched WOOMB.Net, a website selling MSX games in English and other languages, offering 14 games. In Japan, game sales began earlier through Project EGG. WOOMB.Net was the English version of this and other Japanese services provided by D4 Enterprise. In August 2006, D4 Enterprise announced a new MSX2-compatible system called the "one chip-MSX," built using an Altera Cyclone EP1C12Q240C8 FPGA chip. The "one chip-MSX" is similar to the C-One, a Commodore 64 clone also built on a single FPGA chip. The system is housed in a transparent blue plastic box and can be used with a standard monitor or TV and a PC keyboard. It has two MSX cartridge slots and supports audio features like MSX-MUSIC and SCC+. An SD/MMC-flashcard can be used as external storage, acting as a disk drive and allowing the system to boot MSX-DOS. Because of its VHDL programmable hardware, the device can be upgraded by running a reconfiguration program under MSX-DOS. The "one chip-MSX" also includes two USB connectors that can be used after adding supporting VHDL code.

In 2011, AGE Labs announced GR8BIT, a do-it-yourself kit for building an MSX2-compatible computer. The kit, licensed by the MSX Licensing Corporation, includes all necessary parts to assemble a working MSX2 computer except for an ATX chassis, power supply, floppy drive, hard disk, PS/2 keyboard, and monitor.

Some Korean forum members who created Zemmix Neo developed a new MSX-compatible computer called Mini IQ3000 Cutie. It has features similar to Daewoo Electronics' MSX2 model, the IQ-2000. The Mini IQ3000 Cutie is based on the 1ChipMSX but includes special features like a "Scan Line Generator" to improve video quality and "Multi Language Support" for two languages. By default, the machine uses the Korean version of MSX with Korean fonts, but pressing the "del" key during booting switches it to Japanese mode. Even though the default mode is Korean, the default font allocation table is Japanese, allowing it to display Japanese characters when running Japanese software.

In 2019, a group of fans created the MSX Mini Replica, a 1:2 scale reproduction of the Philips VG-8020 computer. It is compatible with software from the MSX, MSX2, MSX2+, and TurboR generations. The device includes two USB ports, an HDMI video output, and uses the same internal hardware as the C64 Mini. Connecting an additional peripheral called MSX Player allows it to run original games from ROM cartridges.

The MSXVR is a computer released in 2020 and compatible with the MSX family of computers. Like the latest Zemmix game consoles, it uses a Raspberry Pi card with added circuitry to connect original MSX peripherals.

In 2022, Nishi announced an official revival of the MSX computer standard called MSX3, which will be available in multiple configurations, including an upgrade cartridge for existing MSX computers. Later, in 2023, after a successful crowdfunding campaign, an IoT device resembling a Game Boy with a keyboard, named MSX0, was introduced for IoT uses alongside the base MSX3 unit. Plans also included a supercomputer called the MSX Turbo X 128, based on cluster technology. The project was stopped after Nishi declared bankruptcy.

Peripherals

The keyboard is a separate part that can connect to a computer using different types of connections. Multiplexed keyboard units have an extra data line that allows sending the scan line number to the keyboard using the same wires used for returning scan code information, which reduces the number of wires needed. Non-multiplexed connections are often used for internal keyboards (and some external keyboards, like the Panasonic CF-3300), while multiplexed connections are used for external keyboards (like the Yamaha YIS805 model).

The keyboard is arranged as a grid with up to 11 input lines and 8 output lines, allowing for up to 88 keys (including all control, number, and letter keys). Each scan line is regularly checked to determine the state of the keys on that line. The speed of these checks depends on how often the system sends interrupts. This setup allows the system to detect the state of each key without the common problem found in keyboards based on the 8042 microcontroller, where pressing more than three keys at once might cause incorrect characters or prevent the system from detecting all pressed keys.

Because keyboard scanning is controlled by system interrupts, one way to check if an MSX machine is working properly when it shows no image (assuming it has power) is to press the CAPS key and see if the LED light changes. If the light does not change, the problem is likely more serious than just the screen not showing an image, such as an issue with the video cable or video display interface.

In 2009, Kamil Karimov created an adapter board to connect a PS/2 keyboard to the multiplexed keyboard interface used by MSX systems. The firmware inside its ATTiny chip was designed specifically for Daewoo CPC machines.

In 2011, AGE Labs added a PS/2 keyboard controller unit, based on a Microchip microcontroller, to its GR8BIT DIY machine. Its firmware converts PS/2 scan codes directly into MSX keyboard scan codes, making it compatible with any MSX-compatible machine and different language settings.

The MSX standard requires at least one cartridge slot, and most models have two. These slots are interchangeable, so it usually doesn’t matter which slot a cartridge is inserted into. The physical connector is a 50-pin edge connector with a 2.54 mm (0.1 inch) spacing. These slots allow a wide range of peripherals to be connected.

Standard game cartridges are about the size of an audio cassette (called "Konami size"). Despite their higher cost, this format was popular because it was reliable and easy to use.

In 1985, Hudson Soft released the Bee Card, a smaller, cheaper alternative to ROM cartridges. However, it was not successful, and few games were released for it.

Source files for developing MSX cartridges are available from AGE Labs using EAGLE software.

Early MSX models did not include a built-in disk drive, so software was initially published on cartridges and cassette tapes.

Mitsumi QuickDisks were introduced as a special feature for MSX systems in 1984 but were quickly replaced by standard floppy disk interfaces. Few games were released in this format.

Sony created a battery-backed RAM cartridge called the HBI-55 "data cartridge" in 1984 for some MSX systems. It could store programs or data instead of using cassette tapes. Many Yamaha music software titles were compatible with this cartridge.

Floppy disk drives became available for MSX systems in 1984, either built-in or as a cartridge containing the disk interface and a BIOS extension ROM connected to an external case. In South America, many systems used 5.25-inch floppy drives, while in Europe, 3.5-inch drives were more common. In Japan, some MSX1 systems, like the Panasonic CF-3300, included a built-in 3.5-inch drive. In Europe, Philips MSX2 systems like the NMS 8230 and NMS-8250 often included 3.5-inch drives with 360 or 720 KB storage.

In 1985, the MSX2 was released, and many models included a built-in 3.5-inch floppy drive. This led to floppy disks becoming the preferred medium for games and software.

The MSX-DOS operating system worked with CP/M but used the same FAT file system as MS-DOS. Its commands were similar to early versions of MS-DOS. This allowed Microsoft to promote MSX for home use while promoting MS-DOS for office computers.

MSX 3.5-inch floppy disks are directly compatible with MS-DOS (though some details like file undeletion and boot code were different). Like MS-DOS 1, MSX disks formatted with MSX-DOS 1 do not support subdirectories.

In September 2012, AGE Labs expanded the standard to support 1.44MB 3.5-inch floppy disks. These disks come in two configurations: Standard (1 sector per cluster, 9 FAT sectors) and Compatible (4 sectors per cluster, 3 FAT sectors).

• Yamaha Y8950, commercially released as: Panasonic: MSX-Audio FS-CA1 (32 KB of SampleRAM, 32 KB of AudioROM), Philips: Music Module NMS-1205 (32 KB of SampleRAM, no MSX-Audio BIOS), Toshiba: MSX FM-synthesizer Unit HX-MU900 (no sample RAM, no MSX-Audio BIOS)
• 9 FM channels or 6 FM channels + 5 drums. Compatible with YM3526.
• ADPCM recording and playback with hardware support.
• Can be upgraded to 256 KB of SampleRAM.

• Yamaha YM2413 (OPLL), also known as: MSX-Music (standard name), Panasonic: FM-PAC, Zemina: Music Box, Checkmark: FM-Stereo-Pak, DDX: FMX, Tecnobytes: FM Sound Stereo (contains the compatible U3567 chip)
• 9 FM channels or 6 FM channels + 5 drums.
• 15 preset instruments, 1 custom.
• Built-in on most MSX2+ systems and standard on MSX TurboR computers.

Emulation

MSX computers are recreated on many platforms today. Early MSX emulators often used code from fMSX, a portable MSX emulator created by Marat Fayzullin. Later versions of some emulators removed Fayzullin's Z80 emulation code to avoid legal issues because fMSX was not free software at the time. Later, the fMSX source code became free for non-profit use, but a license was still needed for commercial use. On December 31, 2013, the Windows version of fMSX 3.7 was released and made free for all users.

The official MSX emulator, MSXPLAYer (in Japanese), is developed by the MSX Association. Kazuhiko Nishi, the inventor of the MSX standard, is the president of this organization.

As of version 0.146.u, MESS currently supports 90% of all MSX versions.

In February 2007, Nintendo of Japan announced that MSX games would be available on the Wii's Virtual Console emulator. The games would cost 700 Wii Points and were expected to be released in Japan starting mid-2007. They later became available on the Wii U on December 25, 2013. A total of 13 MSX games, mostly from Konami, were released for the Wii, and one game was released for the Wii U, all exclusively in Japan.