Because newer release of the original version came out – see note on section It's not the first one, this implement has been closed.

MSX-DOS emulator

written by Cronos


What is it?

MSX-DOS Emulator is just like what the title says. However, it does not support full emulation, but does MSX-DOS BDOS calls only. You can run some MSX-DOS programs(mostly external commands) on Windows DOS prompt. It is specially designed for running MSX-C compiler on DOS prompt and, currently, this emulator is for MSX-C(a.k.a. ASCII-C) only.

Current version of MSX-DOS emulator is 1.0.

This program is really small, simple and buggy, but it won’t crash your hard disk and your precious files. However, if you are feeling like using this, PLEASE USE AT YOUR OWN RISK.

You can download, copy, modify “msxdos.exe” freely. “cygwin1.dll” in the package is a part of Cygwin product. See Cygwin’s license for the information.

It's not the first one

There is an MSX-DOS Emulator already from I eventually found this and ran into the emulator, this was pretty good one. But I had some problem with MX.COM module extracting utility from MSX-C using the emulator on my Windows XP DOS prompt. So I wrote a simple utility which is similar to previous one and here’s the result.

The newer version of Inatcher's MSX-DOS emulator has been out on 2009. 07. 05. The Inatcher said that this version now supports Windows XP command prompt. The version as of 2009. 07. 05. can be found at


  • running MSX-DOS external commands on Windows DOS prompt.
  • running CP/M extarnal commands on Windows DOS prompt.
  • running development tools from CP/M.
  • providing approx. 10KB longer TPA than real MSX-DOS.


  • Input methods of BDOS calls are odd, minimal implementation.
  • Emulator cannot display properly for full-screen’d applications. Emulator does not use curses library.
  • Emulator doesn’t include any MSX BIOS ROM code. Interslot calls to BIOS subroutines may fail.
  • Graphic programs won’t work.
  • This emulator cannot run any MSX-DOS2 programs. Use MSX-DOS1 programs only.
  • This emulator may not run all the MSX-DOS and CP/M programs. See Available section for tested targets.
  • This emulator is not a MS-DOS program but Windows console program. This emulator may not work on any DOS systems.


Download and Installation

Download MSX-DOS emulator via link shown below. Installation is very simple. Put files extracted from MSX-C in a directory and unzip downloaded zip file into the same directory. You may need to have batch files in MSX-C modified for the emulator. contains some examples of these modifications.

How to run

In order to run MSX-DOS programs on DOS prompt window, go to the directory you’ve installed the MSX-C and the emulator on, just type

  C:SOMEDIR> dir wc.c
  C:SOMEDIR> msxdos cf wc

and see what happens. If you can see the compiler’s title and “complete” message, the installation was correct. Full usage is shown below:

    usage: msxdos [emulator options] [MSX-DOS command name] [options]...
    'emulator options' should be given before MSX-DOS command name.
    -d:	debug mode. dump memory usage and Z80 register values.
    -bN:	set break point to N and run internal debugger.
    N could be an address value in decimal(e.g. -b640) or
    hexadecimal(e.g. -b0x4af0) format.
    -e: force to add CP/M EOF(0x1A) at the end of input files.
    MSX-DOS command name:	MSX-DOS or CP/M command file name.
    options:		options for MSX-DOS or CP/M command.

Most commands in MSX-C and MSX-DOS Tools support I/O redirection. It may confuse Windows which has own I/O redirection system also, so if I/O redirection of MSX-DOS programs is needed use double quotation mark(”). Be sure that most MSX-DOS programs don’t support I/O redirection, in the case you use these programs except ones from MSX-C and MSX-DOS Tools, this may not work.

  C:SOMEDIR> msxdos mx -l crun ">temp.bat"

Sample screenshot can be seen on the example page.


Emulator worked with these programs successfully. MSX-DOS emulator doesn’t guarantee running other programs except shown below.

  • Macro-80 - M80.COM, L80.COM, LIB80.COM

Cronos 2010/01/15 15:11

msx-dos_emulator.txt · Last modified: 2016/09/20 09:55 (external edit)
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