Possible to import FM sounds from other chips?

Discussion in 'Technical Discussion' started by MaliceX, Nov 29, 2008.

  1. MaliceX

    MaliceX

    hi i code and quack. Oldbie
    I dunno, I posted a similar topic here at General: http://forums.sonicretro.org/index.php?sho...mp;#entry251339

    Generally speaking, between the different FM chips some of the sounds acutally sound quite similar. At times when listening to FM tunes from the music files found (OVI/OPI/M/M2/MDX) in the above topic, even though they're played through different chips some sounds I believe would be possible to port from one chip to another, and possibly make use in VOPM or something.

    I recall Sonic QX being able to import DX7 sysex files, and now I hear TFM can import OPM (YM2413/VOPM) files. Wonder if it's possible to also extract instrument data from the FMP/PMD (OPI/OVI/M/M2) format music, since they use YM2203 and YM2610 chips anyway? (much closer than YM2612 methinks.)
     
  2. saxman

    saxman

    Oldbie Tech Member
    Any Yamaha chip that is (1) FM, (2) 4 operator, and (3) 8 algorithm will have some level of compatibility (with the exception of the DX9, which is basically in a category of Yamaha FM synths all by itself.) If those chips meet that criteria, I'd say it's very likely you could do something with them.

    Just a minor correction -- I couldn't port anything from the DX7 because it's part of the higher-end line of Yamaha FM synths. It's 6 op / 32 alg. The algorithms are completely different from the 4 op / 8 alg line of synths.
     
  3. MaliceX

    MaliceX

    hi i code and quack. Oldbie
    Ah, thanks for clarifying. (There was something I recall, TX81z patches even? This is a couple years back.)

    Anyway, since info on either stuff is in japanese it's a bit hard to find any useful info or otherwise already-made apps. So far the X68k stuff was rippable.
     
  4. TmEE

    TmEE

    Master of OPL3-SA2/3 Tech Member
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    Does anyone have any info on the FMB files used on FM Towns ? I actually know what all data is, but I'm not 100% sure about all of the bytes that form up the FM instrument.
    All OPN family chips are compatible with each other, and OPM seems to be reasonably compatible aswell (I have manually converted some OPM instruments and the difference in sound seemed to be the matter of what clock target chip uses). MD has it 7.6MHz but a lot of stuff like to use 8MHz so the instruments sound "slower" on MD.
     
  5. saxman

    saxman

    Oldbie Tech Member
    About 5 or 6 years ago, I wanted to document some algorithms for reproducing waveforms on a TX81Z. I did some measurements on the output with each setting and put my findings into a text file. As I went back to double-check some of my work, I was finding that my numbers were off. So I started correcting them, only to find they were wrong (again). What I soon discovered was that the TX81Z's output seemed to change the longer I left it on. Decays became shorter (or longer... can't remember which.) I was never able to come up with any solid algorithms because I had no way to be certain of anything I was typing.

    The moral of the story is, if the other DX-FM chips behave like the TX81Z unit, the output may too be affected by heat. So I'd be willing to argue that processor speed isn't necessarily the only thing to factor into it.
     
  6. TmEE

    TmEE

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    Discrete chip synths should have no such speed issues, at least not YM2612 and improved Sega variant of it found in MD2s.

    I guess you meant synth chip speed here...