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openMSX 0.14.0


openMSX is an open source MSX emulator which is free according to the Debian Free Software Guidelines, available under the GNU General Public License.


For copyright reasons the emulator cannot be distributed with original BIOS ROM images. OpenMSX includes C-BIOS, a minimal implementation of the MSX BIOS, allowing some games to be played without an original MSX BIOS ROM image. You can also use your own BIOS ROM image if you please.


OpenMSX uses a distinctive emulation model to achieve the highest level of accuracy possible. It is available for multiple platforms including POSIX and Microsoft Windows operating systems and emulates a large amount of MSX (related) hardware, including:

  • MSXturboR
  • Moonsound
  • IDE Controller by Sunrise
  • GFX9000
  • Pioneer Palcom LaserDisc


Notable features include:

  • Hard- and software Scalers
  • Debugging
  • Tcl Script Support
  • Cheat Finder (through Tcl)
  • Game Trainers (through Tcl)
  • Audio/Video recording
  • Reverse support (go back in emulated time to correct mistakes or debug what happened)


OpenMSX has an open communication protocol to communicate with the openMSX emulator. Utilizing this communication protocol enables to write versatile add-ons for openMSX. Projects making use of this protocol include the following applications:

  • openMSX Catapult (by the openMSX team)
  • openMSX Debugger (by the openMSX team)
  • openMSXControl plugin
  • NekoLauncher openMSX
  • openMSX Peashooter
  • openMSX Control Plugin for Gedit


Currently Catapult, a GUI developed for the emulator that is part of the project, is being redeveloped utilizing Python and the Qt toolkit.


The openMSX Debugger is also under development, written in C++, also utilizing the Qt Toolkit.


Release Notes for openMSX 0.14.0 (2017-08-03)

This release is another mix of some new features and additions and a lot of smaller fixes and improvements. This release adds support for Konami Ultimate Collection and basic emulation for the Spectravideo SVI-318 and SVI-328 pre-MSX computers, increases FDC accuracy in such a way that we think all copy protections (captured in a DMK file) should now run in openMSX. Moreover, we now put the SDLGL-PP renderer as the default, so let us know how that works for you. You can of course always set the old default setting for your system if you don't like SDLGL-PP. But then we would really like to know why... We also removed the Windows DirectX sound driver, as it was buggy and caused a lot of complaints. And finally, we added a button in the top left corner to easily invoke the OSD menu.


Here's the list with all highlights and details:

  • MSX device support:
    • fixed VDP type of Sony HB-501P
    • fixed a bug that caused hangups on some machines when resetting during the logo animation
    • fixed ROM block debuggable for Sunrise IDE
    • improved accuracy of WD2793 FDC and disk drive emulation
    • added support for Spectravideo SVI-318 and SVI-328 pre-MSX computers:
    • most SVI support was implemented by Tomas Karlsson. With NYYRIKKI's help we fixed most last details
    • added in Contrib a tool to convert SVI disk images to DMK so they can be used in openMSX
    • added SVI support to several scripts (thanks to NYYRIKKI): cashandler, type_via_keybuf, listing
    • note the following limitations:
      • only WAV images are supported for cassettes. The stereo feature (music/sound on the other channel) is not supported.
      • only DMK disk images can be used
      • nothing is done to prevent the user to mix MSX and SVI hardware/software. This will not work, of course. As we are not SVI enthusiasts ourselves, we rely on contributions from others for the SVI support.
    • added accurate M1 cycle emulation
    • added support for ASCII8 mapper with 32kB SRAM
    • added initial support for the ASCII paddle input device (paddle 1 and 2 only)
    • added new machines: Bawareth Perfect MSX1, Al Alamiah AX370 (thanks to alshamaa), and as already mentioned: Spectravideo SVI-318, SVI-328 and a superexpanded SVI-328.
    • added new extensions: Konami Ultimate Collection, ASCII Japanese MSX-Write, ASCII Japanese MSX-Write II and Tecall TM220 MSX-RAMFILE


New or improved emulator features:

  • performance improvements:
    • reverse feature
    • hq resampler
  • fixed issue with remote connections on Mac OS X/FreeBSD
  • changed default sound driver on Windows to SDL, because the DirectX sound driver has been removed
  • fixed creation of new HD images
  • changed the default renderer to SDLGL-PP
  • (probably!) fixed stability of MIDI-in on Windows. Unfortunately we didn't find someone to help us test this properly
  • also improved stability on external connections in general
  • allow to specify initial content for flash ROMs. This way it is possible to use MegaFlashROMSCC+SD like how the actual hardware is also shipped: preflashed.
  • several improvements on the listing command (thanks to NYYRIKKI)
  • added automatic file numbering for record_channels
  • added a tron script (thanks to NYYRIKKI)
  • added script that records to a new AVI file if the framerate changes (thanks to BiFi and FiXato for their initial version)
  • added mapper selection to OSD menu for unknown ROMs
  • automatically pad ROM files if they are not a multiple of the block size, instead of refusing to run that ROM
  • added OSD button to invoke OSD menu in the top left corner
  • added VGM recorder script (by Niek Vlessert) to help you record MSX songs into VGM files, supporting PSG, MSX-MUSIC, MSX-AUDIO, OPL4 and SCC


Build system, packaging, documentation:

  • migrated from SDL threads to C++11 threads
  • removed support for Maemo5
  • moved Windows build to Visual Studio 2017
  • upgraded C-BIOS to release 0.28


And of course the usual various bug fixes and performance improvements.


In "doc/manual/index.html" you can find a set of HTML manuals for openMSX. Make sure you read this if you haven't used openMSX before, but also to learn more about the new and changed features.


CPU and graphics performance varies a lot, depending on the openMSX settings and the MSX hardware and software you're emulating. Some things run fine on a 200 MHz machine, others are slow on a 2 GHz machine. For performance tuning tips, see the Setup Guide.


openMSX is confirmed to run on the following operating systems: Linux, Windows, Mac OS X, FreeBSD, OpenBSD and NetBSD; on x86, x86-64, PPC, ARM, MIPS and Sparc CPU's. Running on other operating systems (wherever SDL runs) or CPU's should be possible, but may require some modifications to the build system. If you are compiling on a new platform, please share your experiences (see below for contact info), so we can make openMSX more portable.


openMSX Home Page: https://openmsx.org/

Project page on GitHub: https://github.com/openMSX

Contact options:


Thanks to all contributors for their feedback, support, bug reports, testing,
coding and other help!


Have fun with your emulated MSX!






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