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Chris
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Yamaha Sound Chip Questions
Post Posted: Thu Feb 17, 2000 2:20 am
I actually took the time to examine the hardware specs that
pop up whenever you run a game and I came to find out
there's TONS of Yamaha chip models. I can tell which
games use Yamaha-type hardware based on it's synthesized
sound but I don't understand the differences between
them. What's the difference between the YM2151
and the 2203? What's the difference between the
YM3812 and the YM2612? All the Yamahas sound the
same to me.

I remember that Paul Jenson explained to me the model used
in the Master System and the model in the Genesis. I
understood that. One's waveform programmable and
the other uses pre-defined wave forms (instrument
table). Are some chips pre-defined and others
programmable? Why did Yamaha produce so many chips
that sound alike?

Chris :o)
 
Chris
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Correction
Post Posted: Thu Feb 17, 2000 2:22 am

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> I actually took the time to examine the hardware specs

That examination came from MAME.

Chris :o)
 
Limbs a Flyin'
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Post Posted: Thu Feb 17, 2000 11:37 am
apart from the predefined Vs. variable part you mentioned, the other major difference is that some chips are 2 operator fm, some are 4 operator fm. (i guess they also make 6, 8 etc etc)

that means the 4 op fm can sound more 'detailed' the the 2 op. thats pretty much it. of course if they all sound the same to you that would be meaningless ;)

in the end, i *think* it means that on a 2 operator chip, a simple wave form gets 'operated' on twice? on a 4 op, it gets operated on 4 times - adding extra complexity and audio richness
confused? ;)
 
  • Joined: 28 Sep 1999
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Post Posted: Thu Feb 17, 2000 10:19 pm

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> table). Are some chips pre-defined and others
> programmable? Why did Yamaha produce so many chips
> that sound alike?

The pre-defined thing only applies to the YM2413 (OPLL), and also
the Konami VRC7 which is a stripped down YM2413 (no percussion
mode and 6 instead of 9 channels).

They made so many chips because as time goes on they updated
existing products. For instance, the YMF-262 is an improved
YM3812, the YM3834 is an improved YM2612, etc. Same reason why
we have Pentiums instead of sticking with 8086's. :)

There's also differences like extra features (ADPCM, DAC, etc.)
and various low-power models all with different part #'s.
Just to add to the confusion, of course.

Don't hold me to this, but I believe the method of sound
generation is somewhat different between the various
families of chips (OPN, OPL, OPLL, OPN-B, etc.) So while you
may have a few chips with very similar specs, they probably
sound quite unique.


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