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MSX1

MSX1 icon MSX1 logo

Overview

Microsoft’s MSX1 standard debuted in 1983 and laid the foundation for a compatible home-computer ecosystem. REG-Linux associates it with the msx platform group so themes and metadata stay consistent.

Quick reference

  • ROM folder: /userdata/roms/msx1
  • Accepted ROM formats: .dsk, .mx1, .rom, .zip, .7z, .cas, .m3u
  • Emulators: RetroArch (libretro: bluemsx, libretro: fmsx), openMSX, CLK
  • System group: msx
Emulator/Core Notes
libretro: bluemsx Accurate MSX1 emulation with sprite-limit removal, rewinding and achievements
libretro: fmsx Lightweight compatibility core that adds netplay
openmsx Official openMSX implementation carried by the openmsx package
CLK Clock Signal provides a low-latency MSX1 option on REG-Linux 42+

Technical specifications

  • CPU: Zilog Z80A running at 3.58 MHz (or compatible clones) with 8-bit bus.
  • Memory: Base 64 KB RAM (banks of 16 KB) expandable via mapper cartridges.
  • Display: Texas Instruments TMS9918 video chip delivering 256×192 resolution, 16 colors out of 32, and 32 sprites.
  • Sound: General Instrument AY-3-8910 PSG providing three square-wave channels and one noise channel.

Supported ROM extensions

dsk, mx1, rom, zip, 7z, cas, m3u, ogv, openmsx

ROMs

Store every MSX1 title inside /userdata/roms/msx1. Wrap multi-disk games in .m3u playlists so EmulationStation shows a single entry (see /cd_image_formats#multi-disc_games).

BIOS

BlueMSX

Fetch the standalone BlueMSX release from http://bluemsx.msxblue.com/rel_download/blueMSXv282full.zip. After unpacking, drop the Databases and Machines directories into /userdata/bios so RetroArch can reference the bundle.

FMSX / Generic MSX ROMs

FMSX relies on plain ROM dumps; copy the list below from the distribution into /userdata/bios:

CARTS.SHA
CYRILLIC.FNT
DISK.ROM
FMPAC.ROM
FMPAC16.ROM
ITALIC.FNT
KANJI.ROM
MSX.ROM
MSX2.ROM
MSX2EXT.ROM
MSX2P.ROM
MSX2PEXT.ROM
MSXDOS2.ROM
PAINTER.ROM
RS232.ROM

openMSX fallbacks

openMSX looks for its BIOS images in the following directories:

  1. /userdata/system/configs/openmsx/share/systemroms
  2. /userdata/bios/Machines
  3. /userdata/bios/openmsx

Emulators

RetroArch

RetroArch hosts libretro: bluemsx and libretro: fmsx for MSX1 hardware. Shared options include msx1.videomode, msx1.ratio, msx1.shaderset, msx1.smooth, msx1.integerscale, msx1.bezel, msx1.bezel_stretch, msx1.hud, msx1.bezel.tattoo, msx1.bezel.tattoo_corner, msx1.bezel.tattoo_file, msx1.bezel.resize_tattoo, msx1.ai_service_enabled, msx1.ai_target_lang, msx1.ai_service_url, msx1.ai_service_pause, msx1.runahead, msx1.secondinstance, msx1.video_frame_delay_auto, msx1.vrr_runloop_enable, msx1.video_threaded.

libretro: bluemsx

blueMSX exposes rewinding, autosave, pad-to-keyboard and achievement toggles (msx1.rewind, msx1.autosave, msx1.padtokeyboard, msx1.cheevos) as well as global.bluemsx_nospritelimits to disable the four-sprites-per-line limit.

libretro: fmsx

fMSX mirrors the same standard options and additionally enables msx1.netplay.

openMSX

openMSX is packaged when you install openmsx. It downloads the same BIOS set as blueMSX/FMSX and reuses the msx1.* option group for video, bezels, AI service and controller mapping.

CLK

CLK (REG-Linux 42+) offers an alternative low-latency MSX1 route using the same BIOS files and option group described above.

Controls

The default MSX1 layout is mapped on the REG-Linux RetroPad overlay.

Troubleshooting

If problems persist, consult the generic support pages.