Last modified on 15 March 2015, at 14:52

MAME

Revision as of 14:52, 15 March 2015 by Morn (Talk | contribs) (ROMs and extension hardware)

The MESS system info box for the CPC6128
MESS also has (still somewhat glitchy) support for the GX4000 and CPC+ series. Note the strange blue bar at the bottom in Pang.

MESS (Multi Emulator Super System) is an emulator for vintage computers, gaming consoles, chess computers, and calculators. It is a descendant of the MAME arcade emulation project and just like MAME, the most important goal of MESS is highly accurate emulation, not speed. MESS and MAME are mainly preservation projects that aim to reproduce the behaviour of the real hardware perfectly, so performance may be slightly worse than many dedicated CPC emulators.

Supported systems and compatibility

Currently, over a thousand systems are supported by MESS, including the CPC and CPC Plus ranges and the GX4000. This is probably the main reason for using MESS: A single download is enough to emulate more or less every home computer and gaming console that ever existed in the late 1970s and 1980s—provided one can find a ROM set that works (see below). MESS does not have the depth of other emulators, but it sure has enormous breadth. Its flexible input mapping and MAME-compatible pixel shader effects make MESS particularly suited for gaming.

MESS runs on Windows, Mac OS X, Linux, and FreeBSD. If you also use MAME, you may want to get UME instead, which combines MESS and MAME into a single executable with a shared configuration file, ume.ini.

On OS X, you can install MESS via Homebrew:

brew tap homebrew/games
brew install mess

The binary is called mess, not sdlmess as on Linux.

Command line arguments

Command line example:

sdlmess cpc6128 -skip_gameinfo -window -flop1 /path/to/disk.dsk
Device options from sysinfo.dat
Name Argument Allowed file extensions
Printer -prin .prn
Snapshot -dump .sna
Disk drive A -flop1 .dsk; .d77; .d88; .1dd; .dfi; .imd; .ipf; .mfi; .mfm
Disk drive B -flop2
Tape -cass .wav; .cdt
Cartridge -cart .cpr; .bin (Plus series and GX4000 only)

Supported file types can also be shown with the "-listmedia" command line option.

You can use zipped disk images too. If there is more than one DSK image in the zip file, treat the zip file like a directory, e.g.

-flop1 disk.zip/disk0.dsk

Keyboard layouts

MESS supports two keyboard modes:

  • emulated (the default; keys are assigned based on key position on the emulated hardware)
  • natural (command line option "-natural"; based on the character generated by a key, e.g. pressing "z" will always generate a "z" on the emulated system)

To use a German keyboard in emulated keyboard mode, start MESS e.g. with (key map path on Linux):

sdlmess cpc6128 -keymap -keymap_file /usr/share/sdlmess/keymaps/km-de.txt

In emulated mode, keys can also be remapped in the emulator menu. First press Scroll Lock to enable the MESS control keys, then Tab to open the menu, and finally select Input (this system). Return, Esc clears an assigned key.

Note that the Delete and Backspace keys are swapped on the emulated keyboard because of the CPC keyboard layout. So you may want to reassign those. Escape on the CPC is mapped to the key left of "1" on the PC keyboard. Alt-Enter switches between windowed and full screen mode.

ROMs and extension hardware

Just as in MAME, some MESS ROMs have parent ROMs that also need to be installed. E.g., cpc6128.zip also requires cpc464.zip to run. (See the links section for CPC ROM files for MESS.)

ROMs often only work with a specific version of MESS. This does not seem to affect CPC ROMs, but other systems sometimes give an error message when ROM filenames or checksums do not match what MESS expected.

Loading external ROMs

You can get a list of slot options with

sdlmess cpc6128 -lslot

These are (as of MESS 0.159):

  • for "-centronics"
pl80 COMX PL-80
ex800 Epson EX-800
lx800 Epson LX-800
lx810l Epson LX-810L
ap2000 Epson ActionPrinter 2000
printer Centronics Printer
digiblst Digiblaster (DIY)
  • for "-exp"
ssa1 Amstrad SSA-1 Speech Synthesizer
dkspeech Dk'tronics Speech Synthesizer
rom ROM Box
multiface2 Multiface II
pds Programmers Development System (CPC Target)
rs232 Pace RS232C interface
amsrs232 Amstrad RS232C interface
sf2 SYMBiFACE II
amdrum Amdrum
playcity PlayCity
smartwatch Dobbertin Smart Watch

The ROM Box expansion can be used to load external ROMs such as MAXAM:

sdlmess cpc6128 -exp rom -rom1 /path/to/MAXAM.ROM

Up to 8 external ROMs (-rom1 to -rom8) are supported this way.

GUI front-ends

Various GUI front-ends for MESS exist for Windows, Linux, and OS X—see this list: [1]

MessMenu on OS X with a CPC ROM selected. Currently, seven different CPC models are supported, including some regional variants (French and Swedish).

CRT simulation

GLSL shader example
HLSL "1980s" shader (detail)

Like MAME, MESS can use shaders to simulate typical CRT graphics artifacts such as scanlines, colors bleeding into each other, jitter, and display curvature. This involves editing mess.ini (or ume.ini if you use UME).

Mess.ini works the same as mame.ini, so MAME tutorials can be used as a starting point. Some example configurations:

  • Windows (using HLSL shaders)
    • A scripted setup with separate "1980s" and "1990s" CRT configs: [2] (huge post is halfway down the page)
    • A German shader tutorial: [3]
  • Linux (using GLSL shaders): MAME tutorial [4]

Remaining issues with CPC emulation

  • MESS may fail to read DSK images with certain kinds of copy protection. Speedlock seems to work fine though.
  • MESS cannot write to disc images in DSK format; only MFI (MESS floppy image) and MFM (HxCFloppyEmulator floppy image) are supported for writing.
  • Some demo tricks may be broken in MESS, e.g. overscan pictures are horizontally misaligned (i.e., shifted to the right).
  • CPC+/GX4000 emulation still has some obvious graphics glitches.
  • The emulated CPC464 has the AMSDOS ROM loaded which is a problem with early 464-only programs that rely on the 464's larger free memory.

JSMESS, a JavaScript port

There is an experimental port to JavaScript, see the JSMESS article for details.

Links