MSX: one standard, a Z80 and Konami's chip

01What you'll learn

• What the MSX standard is and why "one cartridge, any brand" was a new idea.
• What every MSX has in common: processor, video, sound — with exact numbers.
• How MSX, MSX2, MSX2+ and Turbo R differ.
• What the Konami SCC chip adds and why it sits in the cartridge.
• What MSX BASIC can do and what a short program with graphics and sound looks like.
• Which games are well documented (Metal Gear, Snatcher and others) and how to run MSX today.

02Before you start

• No prior knowledge is needed — it is enough to know what a processor, RAM and a sound channel are.
• Optional: a computer for the openMSX emulator 🔒 local or a browser for WebMSX 🌐 global.
• The ROM files of real MSX machines (BIOS and MSX BASIC) and the games have owners. Use only those you have the right to use. The free C-BIOS ships with most emulators, but it has no BASIC.

03Steps

1. The idea: one standard for many manufacturers

   MSX was announced by ASCII Corporation in June 1983; Microsoft conceived the project as an attempt at a single standard, like VHS for video recorders, and Kazuhiko Nishi of ASCII drove it. The first MSX sold to the public was the Mitsubishi ML-8000 on 21 October 1983. Any hardware or software carrying the MSX logo works with products from other brands; even the cartridge format is part of the standard. The standard was built around the Spectravideo SV-328 and from off-the-shelf parts. Why it matters: this is an early attempt at what we take for granted today — software that does not depend on the brand of the machine.

   Part	In MSX (first generation)
   Processor	Zilog Z80A · 3.58 MHz
   Video	TMS9918 · 16 KB video memory · 256×192 · 16 colours (in practice 15 tints) · 32 sprites
   Sound	AY-3-8910 (PSG) · 3 square-wave channels + noise
   RAM	8 KB minimum; most machines had 32 or 64 KB
   Software in ROM	BIOS and MSX BASIC V1.0 from Microsoft
   Cartridges	a cartridge slot — the same on every brand

   💡

   What does "MSX" mean?

   The meaning is disputed. Nishi said in 2001 that the team had in mind "Machines with Software eXchangeability"; many people read "Microsoft Extended" because of the built-in BASIC, and others "Matsushita-Sony". We do not pick a version.
   📊

   The numbers do not agree

   Sales are not known precisely: one source says 9 million machines (7 million in Japan), while Nishi speaks of 3 million in Japan and 1 million overseas. In Japan, South Korea, Argentina and Brazil MSX was the leading home computer of the 1980s. Manufacturers included Sony, Panasonic, Yamaha, Philips, Toshiba, Sanyo and many more.

2. The four generations

   Generation	Year	Video	Note
   MSX	1983	TMS9918	Z80A 3.58 MHz; worldwide
   MSX2	1985	Yamaha V9938 · 128 KB video memory	SCREEN 8: 256×212 with 256 colours; 512×212 modes with 4 or 16 colours from a 512 palette; hardware vertical scrolling; RAM 64 KB minimum; e.g. Panasonic FS-A1, Sony HB-F1
   MSX2+	1988	Yamaha V9958	officially Japan only; YJK modes up to 19,268 simultaneous colours; e.g. Panasonic FS-A1WX, Sony HB-F1XDJ
   Turbo R	1990	V9958	R800 processor at 7.16 MHz; two models: Panasonic FS-A1ST (256 KB RAM) and FS-A1GT (1991, 512 KB); Japan only

   ⚠️

   The partnership had an end date

   In 1986 Microsoft ended its partnership with ASCII. MSX3 was planned for 1990, but its video chip was late; in its place came the Turbo R with the R800 processor. The R800 was developed by ASCII, with some of its features (DMA, 24-bit addressing) disabled.

3. Sound: PSG and Konami SCC

   The standard MSX sound is the three-channel PSG chip. Konami decided to boost it with the SCC (Sound Custom Chip or Sound Creative Chip), developed by Konami together with Yamaha. The chip sits on the cartridge's own board next to the ROM — so every SCC game carries its own chip. It adds 5 channels that work together with the PSG sound.

   Term	Value	What it means
   PSG	3 channels	square wave + noise only
   SCC (mark 051649)	5 wavetable channels	waveform of 32 signed bytes; channels 4 and 5 share one waveform; each channel has on/off, volume and frequency
   How it is accessed	9800h–9FFFh	mapped into memory (not through I/O ports); the documentation is reverse-engineered, not official
   SCC+	64 KB RAM on the board	used by Snatcher and SD Snatcher; allows a different waveform for each channel

   ✅

   Rule: the SCC is an "add-on", not "built into MSX"

   Without a cartridge with the SCC (or a compatible cartridge) the machine sounds only with the PSG. The first cartridge with the SCC is Nemesis 2 (Gradius 2) of 22 August 1987, not Nemesis of 1986. Only a few MSX/MSX2 games use the chip — among them Nemesis 2, F-1 Spirit, Salamander, Parodius, Nemesis 3, Space Manbow and Metal Gear 2 (the list with RC 7xx numbers is in the Ultimate MSX FAQ).

4. MSX BASIC: the first step

   MSX BASIC is a dialect of Microsoft BASIC: an extended version of MBASIC 4.5 with graphics, music and peripherals. When the machine starts without a cartridge, its command prompt appears; program lines carry numbers, while lines without a number run immediately. Version 1.0 is 16 KB and has SCREEN 0 (text 40×24), 1 (32×24 with sprites), 2 (256×192, 16 colours) and 3 (low resolution 64×48).

   MSX BASIC · graphics, sprite and melodycopy

   10 COLOR 15,4,4 : SCREEN 2
   20 LINE (10,10)-(100,100),8,BF
   30 CIRCLE (128,96),30,12
   40 PSET (200,150),15
   50 S$="" : FOR I=1 TO 8 : READ A : S$=S$+CHR$(A) : NEXT I
   60 SPRITE$(0)=S$
   70 PUT SPRITE 0,(100,100),8,0
   80 PLAY "V15T120O4L8CDEFGAB"
   90 GOTO 90
   100 DATA 60,126,255,255,255,255,126,60

   • COLOR foreground, background, border — in that order.
   • SPRITE$(0) sets the sprite pattern (8 bytes for 8×8), and PUT SPRITE shows it: plane number, position (X,Y), colour, pattern.
   • PLAY reads a music string and plays it through the PSG; V is volume, T tempo, O octave, L note length.
   • SOUND register, data writes a number into a PSG register — it does not "stop the sound". SOUND works with the PSG; the SCC is a separate chip mapped into memory (see the previous step).
   ⚠️

   Not tested live

   The example was composed from the MSX BASIC documentation (MSX2 Technical Handbook) but has not been run in an emulator — that is why there is no TESTED label. Run it in an emulator with a real MSX BASIC.

5. Konami's games

   Konami is the best-known publisher for MSX. Here are eight titles with verified facts.

   Game	Date · platform	What it is
   Penguin Adventure	28.10.1986 · MSX	A racing game with platform elements, sequel to Antarctic Adventure (1983). Penta the penguin seeks a golden apple for Penguette. Kojima took part in the planning for about a month (his professional start) but is not in the credits.
   Vampire Killer	30.10.1986 · MSX2	A parallel version of Castlevania a month after the Famicom Disk System version; in Europe it was released without the Castlevania name. Simon Belmont against Dracula, but with more searching for keys and items than the NES version.
   Nemesis 2 (Gradius 2)	22.08.1987 · MSX	A horizontal shooter; Konami's first cartridge with the SCC. The ship is Metalion, not Vic Viper.
   F-1 Spirit: The Way to Formula-1	1987 · MSX	Formula 1 with a top-down view; uses the SCC; the engine is close to Road Fighter.
   Metal Gear	July 1987 · MSX2	Kojima's first game as a developer; Solid Snake infiltrates Outer Heaven.
   Snatcher	13.12.1988 · MSX2	An adventure by Kojima; the MSX2 version comes on three floppy disks with a sound cartridge with the SCC+.
   SD Snatcher	27.04.1990 · MSX2	A Snatcher spin-off; again three floppy disks and an SCC cartridge.
   Metal Gear 2: Solid Snake	20.07.1990 · MSX2	A sequel written and designed by Kojima; uses the SCC.

6. Metal Gear and the idea of stealth

   Metal Gear was conceived as a pure action game, but under Kojima it was redirected to avoiding enemies — against the shooters of the day, with an emphasis on evasion similar to Pac-Man. The game has a radio that delivers conversations and story. Today Metal Gear is regarded as the first mainstream stealth game and a pioneer of stealth mechanics. Metal Gear 2 adds kneeling and crawling, noise from your actions, a 3×3 radar, and guards with a 45-degree field of view who hear sounds and investigate where they came from.

   💡

   Not "the first stealth game" without a caveat

   The claim that Metal Gear is "the first" is more accurate as "the first mainstream" (Wikipedia). We do not claim that nobody had made a game about hiding before it.

   Metal Gear 2 was not officially released in the West as an MSX2 game: it got its first international release in Metal Gear Solid 3: Subsistence in 2006, with an English translation. A fan translation from 1997 circulated earlier. Reviews: GameSpy calls it "one of the best 8-bit games ever made", while Game Informer gives it 7 out of 10.

7. Yamaha CX5M: MSX with an FM synthesizer

   The Yamaha CX5M is an MSX-compatible computer from 1984 with a built-in 8-voice FM synthesizer (YM2151 in the SFG-01 modules) and MIDI. Yamaha offered cartridges: a voice editor and a sequencer. The first version has MIDI as output only — for the Yamaha DX7; the second (CX5M II) with the SFG-05 module also accepts MIDI input, so the internal synthesizer can be played from an external keyboard. The CX5M was one of the few MSX machines sold in the USA.

8. Timeline

   Date	Event
   June 1983	ASCII announces MSX (sources give two dates in June).
   21.10.1983	The first MSX on the market: Mitsubishi ML-8000.
   1984	Yamaha CX5M with an FM synthesizer.
   1985	MSX2 (V9938).
   1986	Microsoft ends the partnership with ASCII; Penguin Adventure (28.10) and Vampire Killer (30.10).
   1987	Metal Gear (July); Nemesis 2 (22.08) — the first cartridge with the SCC.
   1988	MSX2+ (Japan); Snatcher for MSX2 (13.12).
   1990	Turbo R (FS-A1ST); SD Snatcher (27.04); Metal Gear 2 (20.07).
   1991–1993	FS-A1GT (1991); the Turbo R was discontinued in 1993 (per Wikipedia).
   2006	Metal Gear and Metal Gear 2 reach the West in Subsistence.
   Today	openMSX 21.0 (26.09.2025), WebMSX 6.0.8; a community around the MSX Resource Center.

9. Try it yourself: MSX in an emulator

   openMSX 🔒 local is an open-source emulator that describes itself as "aims for perfection". The current version is 21.0 (26.09.2025), for Windows, macOS and Linux. WebMSX 🌐 global runs in the browser (version 6.0.8). The steps in principle:

   1. Download openMSX from its official site or open WebMSX.
   2. Choose an MSX2 (or MSX1) machine and system ROM files you have the right to use; C-BIOS works for cartridge games but not for BASIC.
   3. Insert your own cartridge or disk image and start. For the example above you need a real MSX BASIC.
   ⚠️

   Not tested live

   We did not run an emulator for this lesson. We do not know exactly how WebMSX provides the system ROMs — follow its documentation. We describe openMSX's menus only in principle.
   ⛔

   Copyright

   Games and system ROMs have owners. Do not upload or distribute other people's images.

04Check

Checklist

• I know the processor and clock of MSX (Z80A, 3.58 MHz) and when the first MSX went on sale (21.10.1983).
• I can list the four generations and their video chips.
• I know what the SCC adds (5 wavetable channels) and which cartridge was first (Nemesis 2).
• I know the order of the COLOR arguments and what SOUND does.
• I know two ways to run MSX today and the caveat about ROM files.

Quiz

05What's next

06Sources

1. MSX (Wikipedia) — standard, dates, generations, manufacturers, sales.
2. MSX BASIC (Wikipedia) — SCREEN modes, versions.
3. MSX2 Technical Handbook (GitHub) — syntax of COLOR, SOUND, PUT SPRITE.
4. Konami SCC (Wikipedia) — channels, addresses, SCC+.
5. Nemesis 2 (Wikipedia) — the first cartridge with the SCC · The Ultimate MSX FAQ: SCC — list of SCC cartridges.
6. Games (Wikipedia): Metal Gear · Metal Gear 2 · Penguin Adventure · Snatcher · Vampire Killer · F-1 Spirit.
7. Yamaha CX5M (Wikipedia) — FM module and MIDI.
8. openMSX 🔒 local — emulator, version 21.0.
9. WebMSX 🌐 global — in-browser emulator, version 6.0.8.
10. C-BIOS — a free compatible BIOS, without BASIC.
11. MSX Resource Center 🌐 global — community, wiki, news.
12. Generation MSX 🌐 global — a software and hardware database (the site asks for age confirmation for part of its content).