ChanServ changed the topic of ##yamahasynths to: Channel dedicated to questions and discussion of Yamaha FM Synthesizer internals and corresponding REing. Discussion of synthesis methods similar to the Yamaha line of chips, Sound Blasters + clones, PCM chips like RF5C68, and CD theory of operation are also on-topic. Channel logs: https://freenode.irclog.whitequark.org/~h~yamahasynths
<ej5>
going elsewhere?
<ej5>
also cr1901_modern at some point i'd like to put up a reverse engineered and commented listing of the SB 2.0 firmware
<ej5>
something that you shouldn't look at if you really want to clean room it lol
<ej5>
but i'm sure Lord_Nightmare would be interested in the commented version
<cr1901_modern>
ej5: Put an encrypted copy and give everyone you want to send it to _except me_ the private key :P
* cr1901_modern
is being serious
<cr1901_modern>
Yes, you can trust me not to look at it
<ej5>
hmm interesting idea although i think github doesn't support that
<cr1901_modern>
Anyways the clean room thing is just an abundance of caution
<cr1901_modern>
Make it a private repo and give anyone who asks access (except me)?
<Lord_Nightmare>
ej5: sure i'd love to see the commented version even if it can't be released right now
<Lord_Nightmare>
i'd relaly love to see the 'other' sb 2.0 firmware, the one one version older than the one we have
<ej5>
i'll let you know when i put it together
<Lord_Nightmare>
which someone on twitter had on a card
<ej5>
the binary has already been released to the roms email for mame
<Lord_Nightmare>
i assume only early sb-"2.0" cards with the plcc mcu had the older version
<Lord_Nightmare>
iirc the version you have is... 2.03?
<Lord_Nightmare>
and that one was 2.02?
<Lord_Nightmare>
or is it 2.02 and that one was 2.01
<Lord_Nightmare>
i don't remember
<Lord_Nightmare>
i'm guessing it has an interesting bug in it
<ej5>
yeah this one is 2.02
<ej5>
it's got a bug in the ROM CRC function
<Lord_Nightmare>
2.01 does? or 2.02?
<Lord_Nightmare>
or both
<ej5>
umm, also it has some undocumented functions including a "playback from RAM" that plays 63 samples from RAM
<Lord_Nightmare>
given the code is probably 99% the same between 2.01 and 2.02
<ej5>
i don't know about 2.01 but i'd guess it has the same CRC bug
<cr1901_modern>
Someone here recently mentioned that a 3.5" floppy drive is expected to take up to 1A of current on the 5V line. Anyone remember who that was, and what the source was?
<Lord_Nightmare>
sounds like something diskblitz would have said
<Lord_Nightmare>
but i don't remember who said it and when it was said
<andlabs>
and there's another one in a different box that was sold in a bundle with a keyboard
<andlabs>
incidentally there were three of these standalone on sale at the time you made that link and the two you see are the *other two* — the one you linked is still on sale
<whitequark>
Sarayan: 2.4A can be done over special "charging" ports
<whitequark>
which you mostly find on, well, chargers
<whitequark>
you cannot draw 2.4A without detecting shorted D+/D- (iirc), which prevents you from communicating of course
<whitequark>
then with USB PD you can just negotiate everything
<cr1901_modern>
andlabs: Hey, I'm happy for you that you have an original OPL and I hope you put it to good use as opposed to displaying it on a shelf :)
<andlabs>
what shelf
<andlabs>
it's clearly in a box :V
<andlabs>
anyway yes I totally intend on doing preservationy things with these
<andlabs>
one of those boxes has the software on disk and the other had software on tape
<andlabs>
all the SFX modules were distributed as both
<andlabs>
I will be preserving ALL of them
<andlabs>
and no, I'm not going to be snobby at you anymore, don't worry
<andlabs>
sorry
<andlabs>
just wanted to tease a very tiny bit
<andlabs>
you really should get one of these, they aren't rare — just expensive for no good reason
<superctr>
well, OPL is like the demo tape
<superctr>
OPL2 is the full album, OPL3 is the boxset and OPL4 is the remix album
<andlabs>
in fact, being expensive is the reason why these things failed
<andlabs>
commodore uk didn't smart
<andlabs>
superctr: by that logic OPL4 is weaker than OPL3
<superctr>
well, the OPL4 was only sold "bundled" with the OPL3
<andlabs>
...????
<andlabs>
wat
<andlabs>
that makes no sense
<superctr>
in that the OPL3 is fully integrated into the chip
<andlabs>
oh
<andlabs>
I thought you meant they were sold together
<andlabs>
for some reason
<superctr>
there is a ROMpler-only version of the OPL4 though, with the sample rom integrated in the sound chip (like the rhythm in the 2608)
<superctr>
those actually lack the FM part and since you can't have external sample memory, it's really weaker than the OPL3
<andlabs>
okay, yikes
<andlabs>
so there is no true ultimate OPL chip then
<superctr>
then there is OPL4-ML, which still has the built in sample rom, but at least keeps FM
<andlabs>
at least there was only one OPM chip (that may change once I figure out what these extra registers in the OPP chip are)
<superctr>
regular OPL4 is best in that regard. It has the full OPL3 (though OPL3 itself removed CSM if you care about that), and the sample part which uses external memory
<andlabs>
...OPL2 had CSM?
<andlabs>
I wonder how bad that must have sounded
<superctr>
original OPL had CSM
<superctr>
OPL2 kept it, but it was removed in OPL3
<andlabs>
yeah but
<andlabs>
'only two formants
<andlabs>
that can't possibly produce anything pleasant
<superctr>
another thing, OPL4 also has resampled FM output to 44.1khz like the later OPL3 variants
<superctr>
CSM on OPL and OPM uses all channels/operators
<andlabs>
I still haven't received the japanese FM Music Macro manuals I ordered (have to contact goboy) in order to evaluate how that sounds
<andlabs>
nut I need to record the output of the error message that I do get when using the say command icorrectly because it sounds okay-ish
<andlabs>
and that's probably as good as I'm going to guess
<andlabs>
get
<andlabs>
and that's four-op
<superctr>
on OPL and OPM all channels are used in the CSM mode, not just CH3 like on the OPN
<andlabs>
actually I shouldn't call up goboy hmm
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<andlabs>
this is a hard time for everyone :S
<andlabs>
but what does that give you - full n-formant synthesiss or n/(2,4) channels of (2,4)-formant synthesis?
<andlabs>
er
<andlabs>
superctr: but what does that give you - full n-formant synthesiss or n/(2,4) channels of (2,4)-formant synthesis?
<superctr>
well, how do you define it
<superctr>
you can adjust the frequency directly of each channel, so that would be 9 on OPL and 8 opn OPM
<superctr>
but on OPL you can only adjust the multiply level of each operator for harmonic sounds
<superctr>
on OPM you also have two detune parameters for each operator
<cr1901_modern>
I thought it was just one big detune split across two regs
<superctr>
not really
<superctr>
DT1 is a very fine detune setting, that is barely audible unless your operator multiply level is very high
<superctr>
DT2 is coarse and produces a transposition effect, the lowest setting adds 600 cents (half an octave)
<balrog>
Sarayan: if you're powering off the same port as the psoc board, the psoc probably can be programmed to request more power
<andlabs>
ah, so there's no modulation here at all
<andlabs>
hmm
<andlabs>
in that case yeah I guess you could theoretically play complicated passages by stringing channels together
<andlabs>
maybe
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<ej5>
well i just spent the better part of an hour tracking down a problem in a Plaid Bib. turns out it was a bad YM3812. -_-
<ej5>
symptoms: steady oscillations at 800Hz and 3.8KHz after power up. disappeared momentarily when IC# pulsed low, but then came back. stayed until i ran a program that actually sent it data.