openMSX 0.5.1

by MSX Resource Center on 21-04-2005, 00:00

openMSX is an opensource MSX emulator that aims to emulate every aspect of the MSX computer to perfection. This means that not only the usual MSX computers and hardware are supported, but rare hardware like the Panasonic MSX-Audio, MegaRAM, RS232 and even Sunrise's IDE interface can be emulated. Furthermore, the emulator is capable of emulating a wide range of MSX machines specifically. As of version 0.5.1, the first steps of emulating the Sunrise GFX9000 video cartridge (which contains the Yamaha V9990 VDP) have been taken. An increasing amount of software for this cartridge is currently under development. WIth this, openMSX is the first emulator to emulate the last and best VDP ever developed for MSX.  


Right from the first release, openMSX has always been praised for its high accuracy. openMSX was one of the first MSX emulators to emulate turboR and Moonsound and also was one of the first MSX emulators capable of running the entire Unknown Reality demo without any glitches. openMSX is also known for its configurability. About everything you can think of can be configured before and during emulation including such things as which renderer to use (SDL or openGL), what accuracy setting should be used (screen, line or pixel) et cetera, et cetera. This can either be done in the GUI or in the console which appears on top of the emulated MSX after pressing F10.  


There are downsides as well, though. Look around on the internet and you'll see quite some complaints on the usability of openMSX. User-friendliness has, however, greatly improved since the introduction of the openMSX GUI Catapult. The Windows version even comes with a neat installer these days. Even though the extreme amount of options and hardware that can be selected might confuse people who 'just want to run a game on an MSX2', the only really annoying thing we could find in the Catapult GUI was the fact that the tab where ROM and DSK images can be changed does not contain a reset button. It could have saved us quite some clicks during our tests.  




We ran the accuracy tests of openMSX using the SDLHi renderer, set on pixel accuracy. As expected from an emulator that is known for its high accuracy most MSX2 and all turboR tests ran without any problem whatsoever. In fact, every single test we ran managed to score 4 or 5 points, which is absolutely outstanding. The minor penalties were caused by minor glitches like flickering buildings in the multilayer scroll of Almost Real, a few unstable screensplits in Metal Limit and not exactly correct timing between images and sound in the SD-Snatcher introdemo.  




openMSX is one of the emulators that emulates all the essential MSX music chips (and more). PSG, MSX-AUDIO, MSX-MUSIC and SCC all sound good enough to express the atmosphere these chips can add to MSX software. As with all other emulators in the test I'm still missing the warmth and depth the 'real thing' provides, especially when it comes to the drums of the MSX-MUSIC. During the SCC tests we noticed some slightly annoying flaws, like some hickups in the flute sound of the SD-Snatcher introdemo. openMSX certainly isn't doing a bad job, though. The sound quality of the OPL4 emulation has improved greatly since the previous release and we no longer had trouble playing PSG samples such as those in Aleste 2.  




The accuracy combined with the amount of features of openMSX is truly impressive. Ever since the introduction of Catapult openMSX has greatly improved in usability as well. openMSX is, however, not the ideal emulator for people who just want to play a game or two. Those games will probably run on most other emulators in this test as well, which are likely to be even more user-friendly. openMSX is ideal for the advanced MSX (emulator) users and developers, who know exactly what they want (and what they are talking about). People who want to test software on exotic MSX machines or hardware, or who just want to play around with such configurations. As openMSX is likely to run about all MSX software without any serious glitches, it could also be used as a great tool for testing compatibility of software on a wide range of different MSX computers. At the moment openMSX already is very interesting for developers, once a NO$MSX-like debugger was added to the emulator, it could very well become an essential cross-developers tool.  


Information chart

MSX2 CPU Benchmark:         993
MSX2 VDP Benchmark:         993
turboR CPU Benchmark:       983
turboR VDP Benchmark:       994
MSX1/2 accuracy score:      96.25%
turboR accuracy score:      100.00%
Music quality score:        70.00%
Usability & Features score: 70.58%
CPU load MSX2 idle:         ~ 30.00%
CPU load turboR idle:       ~ 45.00%
MRC EmuRank:                85.51%
Emulator interface:         GUI
Save-states:                no
Screenshots:                yes
Joystick support:           yes
Mouse support:              yes
Printer support:            yes
Real disk support:          no
Multi-disk support:         no
Change disk:                yes
Dir as disk:                yes
MSX1 palette:               yes
Image enhancements:         yes
Fullscreen:                 yes

openMSX website:


To see how openMSX compares to other emulators, check out the MRC EmuRank chart.

Comments (7)

By Vampier

Prophet (2405)

Vampier's picture

09-03-2005, 21:30

no word on Gfx9000, although in a early stage it should have been included in the tests... and imho it should also be included in all future tests on all emu's.

there can be only 1! (or 2 in this case Tongue)

By snout

Ascended (15187)

snout's picture

09-03-2005, 22:22

Please -do- check the first paragraph of this text again, will ya? Smile

By Edwin

Paragon (1182)

Edwin's picture

09-03-2005, 22:37

Mentioning it is not really the same as including it. However, considering the limited usage of it (for now), I'm not too sure that it should count for much in the rank anyway.

By snout

Ascended (15187)

snout's picture

09-03-2005, 22:40

I'm thinking of adding it as 'bonus points' in a future comparison, which will feature some more extra tests. Theoretically, the perfect emulator will be capable of getting a 110% EmuRank in that construction Wink

By Manuel

Ascended (19227)

Manuel's picture

09-03-2005, 22:54

Maybe you could also give points for the amount of MSX devices emulated... .But you were probably going to do that with your new U&F score stuff.
In my opinion, an emulator consists of two main types of features:
1) emulated MSX devices. Also the quality of that emulation counts, of course.
2) features that are extras; make use of the fact that you're emulating to get some special options not possible on a real MSX. Examples: always working pause, speed controls, screenshots, debuggers, VU meters, skins, scalers, etc, etc.

It might be nice to use some kind of split up like this in the comparisons. Ah well, just some ideas.

By BiFi

Enlighted (4348)

BiFi's picture

04-04-2005, 20:30

Hmm... I wonder how the R800 accuracy could be 100% when there are still accuracy issues...

By snout

Ascended (15187)

snout's picture

04-04-2005, 20:49

...because a 100% score on turboR accuracy doesn't mean an emulator can run 100% of all MSX turboR software without any glitches at all. It only means I could not detect accuracy issues in the turboR tests I ran.