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>
i've found it's best to keep components/backstock *really well organized* otherwise you're better off ordering parts instead of endlessly searching
<TD-Linux>
I use boxall organizers so I can have lots of smd in a very small space. but I don't have some global search tool for parts - usually each project I order a full BOM, and then use any extras for later rework
<cr1901_modern>
TD-Linux: well, strictly speaking that's what I did
<cr1901_modern>
I still ended up losing one during rework lol
<cr1901_modern>
I'll look for it tomorrow
<TD-Linux>
I'm slowly getting better. for the ulx3s I managed to only lose one blue led over the 190 parts on there
<cr1901_modern>
or deliberately try to lose something else I need so the resistor appears from a wormhole somewhere
<Wohali>
i have this large drawers unit manufactured in the 1950s. lots and lots of little drawers in it. very useful
<cr1901_modern>
I need lots of antistatic foam, tbh
<Wohali>
i don't keep SMT inventory right now, I do what TD-Linux does
<cr1901_modern>
lots of thru-hole parts, not enough foam (or the foam I have is too thick)
<Wohali>
but i have a few spools of parts from a friend
<Wohali>
cr1901_modern: aluminum foil works
<Wohali>
stack the ICs and wrap em in foil
<Wohali>
then write the part number on the foil in marker
<Wohali>
way cheaper than foam!
<cr1901_modern>
Wohali: I don't need the foam for antistatic purposes; I need them for "I want them to stay put" purposes
<Wohali>
*ah*.
<Wohali>
Well, ICs wrapped in foil and stacked stay put more because they're more massive and larger, at least in small drawer units.
<Wohali>
But I get your jist.
<cr1901_modern>
something shifted position slightly on the table adjacent to my workbench and now I'm losing my mind b/c I can't figure out what changed. Paradoxically, cleaning it up a bit made it _more_ crowded
<cr1901_modern>
The things on that table don't fit in the places as nicely as I had them before the cleanup today
<Wohali>
here's a religious question for y'all: for cleaning a soldering iron, do you prefer a moist silicone sponge or a dry brass coil tip cleaner?
<Wohali>
I tend to prefer silicone sponges, but I have the brass coil as well.
<cr1901_modern>
you're supposed to use brass, but I use a sponge
<Wohali>
i think the "supposed to" has been sufficiently debunked, personally.
<Ultrasauce>
I use one or the other depending on whether I happen to have a glass of water next to me at the time heh
<whitequark>
Wohali: i use neither
<Wohali>
whitequark: oh?
<Wohali>
Sal Ammoniac?
<whitequark>
i take stainless steel tweezers and carefully remove the carbonized gunk with its edge, then use an ordinary cellulose sponge as usual
<Wohali>
ok, so *dry* cellulose sponge. got it
<whitequark>
no, wet
<Wohali>
ok, got it
<whitequark>
dry cellulose sponge would just destroy it
<whitequark>
but you need to actually scrape the contaminants with something first
<Wohali>
eh, as long as they're not on the tip...scraping can damage the coating. you don't immediately retin after scraping?
<cr1901_modern>
Wohali: Do you have a picture/examples of how you wrap them in Al. foil? How high do you stack them?
* cr1901_modern
has a grab bag of TTL components
<whitequark>
the coating on my T12 tips is harder than the tweezers though
<Wohali>
cr1901_modern: i don't have a photo, no. usually no more than 10 in a stack for convenience
<cr1901_modern>
Did you actually test that a la mohs scale?
<cr1901_modern>
test the T12 hardness versus tweezers*
<Wohali>
a 100g bar will last you a lifetime.
<cr1901_modern>
hmmm
<Wohali>
a trick with it is to never touch the iron itself directly to the block, but to melt a ball of solder onto the block, then roll it around with the soldering tip. that picks up enough of the ammonium chloride
<whitequark>
cr1901_modern: no, but the tip coating is usually some sort of hard chrome plating
<whitequark>
it's true that brass is safer, but the tweezers method works better on really dirty tips
<whitequark>
where you have to specifically remove dirt from especially soiled spots
<whitequark>
sal ammoniac helps but not that much
<whitequark>
i had more success with rosin and ordinary solder after manual cleaning of the tip vs sal ammoniac
<whitequark>
this of course depends on the tip coating
<cr1901_modern>
Unrelated: Why is 99 isopropyl alcohol so much better at cleaning than 70%? What's so special about that extra 29%?
<Wohali>
the water doesn't evaporate
<Wohali>
so you're just sloshing water onto components
<cr1901_modern>
mmm
<Wohali>
i am currently working on an (analog) yamaha synth recap. lotsa work.
<whitequark>
i use acetone for most cleaning :P
* whitequark
← heterodox
<Wohali>
mmm VOCs
<whitequark>
sure, you need to know which plastics can't tolerate it, but everything else cleans like 5x faster and 2x better than ipa
<whitequark>
and then you can go over the rest with IPA
<Ultrasauce>
its so damn volatile though
<cr1901_modern>
Second time I've heard heterodox this week... frequency illusion strikes again
<whitequark>
no it's not an illusion
<whitequark>
i've used that word because i've heard it a few days ago and i like how it sounds
<Wohali>
i use meths on most of my metal stuff
<whitequark>
methanol isn't sold over here
<whitequark>
and i probably wouldn't use it for toxicity
<Wohali>
not methanol
<whitequark>
oh?
<Wohali>
methylated spirits
<whitequark>
oh, denaturated ethanol
<whitequark>
>In the United States, mixtures sold as denatured alcohol often have much greater percentages of methanol, and can be less than 50% ethanol.
<whitequark>
well this just seems unreliable
<Wohali>
i tend to buy from industrial sources with reliable supply chains and MSDS. :)
<Wohali>
and when i'm doing that sort of cleaning, it tends to be something horrid like an internal combustion engine...
<Ultrasauce>
denatured alcohol here is usually 99% ethanol with some bitterant i think
<Ultrasauce>
which is about as effective as isopropanol
<Wohali>
or something that needs replating/electroplating/etc
<whitequark>
see i'm in a weird country where i can buy bromine by the kilo no questions asked, but obtaining ethanol is a multiple week quest
<Wohali>
which country is that
<whitequark>
russia
<Wohali>
got it
<Wohali>
plastics is different...
<Wohali>
i usually start with soap+water
<Wohali>
or Goo Gone
<whitequark>
depends on what i'm cleaning out
<whitequark>
usually when i work with plastics it's something on a pcb
<whitequark>
a connector or a display
<Wohali>
acetone's great but you really have to know what plastics you're on
<whitequark>
yep
<whitequark>
fortunately most heat resistant plastics are also acetone resistant, i think a lot of connectors use PS
<whitequark>
er, no, wrong acronym
<whitequark>
polysulfone
<Wohali>
when i fab PCB stencils I use an etchant comprised of acetone + HCl
<whitequark>
the cheap ABS shrouds on big connectors like multiport LAN or DE-9 are bad
<whitequark>
things like FPC connectors don't care
<Ultrasauce>
what do you do for patterning/resist Wohali?
<whitequark>
it's definitely not something i can recommend to everyone
<Wohali>
Ultrasauce: right now, just straight up laser toner, transferred with an iron + rolling pin. tho I want to try some of those sheets of whatsit stuff you can get on eBay
<Ultrasauce>
photoemulsion film?
<whitequark>
oh, looked it up, the FPC connectors are usually aramide, stuff like SD or SIM card slots look like polysulfone
<Wohali>
no, not that
<Wohali>
toner transfer paper
<Ultrasauce>
ah yes
<Wohali>
right now i use glossy magazine paper as the toner transfer paper
<Wohali>
the covers of magazines work best, nice and glossy
<Wohali>
but increasingly they're using worse and worse paper, so i think i should try the toner transfer paper next
<Wohali>
whitequark: yeah, anything that smells or looks like Kapton tape is fine with Acetone
<Wohali>
polyimide
<whitequark>
the fpc connectors are more like nylon
<whitequark>
same deal though
<Wohali>
are they? neat!
<Wohali>
this is the kinda shit they should be teaching in western schools, damn it. makes me angry.
<whitequark>
i looked it up on vendor websites, yeah
<Ultrasauce>
a bunch of stuff is polyphenylene sulphide also
<whitequark>
ohhhhh
<whitequark>
that's a new one for me
<whitequark>
i've guessed polysulphone but PPS seems like a better match now that i look at it
<whitequark>
very interesting, thanks
<whitequark>
looks like polyetherimide is also used
<whitequark>
i really need to systematically study the plastics used in connectors
<whitequark>
yeah, now that i check again, polysulfone is mostly hydraulics
<whitequark>
though it's somewhat similar to polyphenylene sulphide in structure
<cr1901_modern>
I actually managed to save a botched/broken board lmao
<cr1901_modern>
Now only 99 more to go before I have a 50% success rate
<Wohali>
gz
<cr1901_modern>
gz?
<Wohali>
gratz
<Wohali>
congratulations
<Wohali>
sorry, MMO abbreviation
<cr1901_modern>
Ahhh I see. For perspective, the newest system I own is a DS (not 3DS. DS.)
<cr1901_modern>
I've long been out of games
<whitequark>
did you destroy 100 boards?
<whitequark>
that's a lot of boards
<cr1901_modern>
mild exaggeration, but my success rate for rework/fixing stuff is pretty abysmal
<Wohali>
cr1901_modern: for someone who is obsessed with OPx chips, I'm surprised. :)
<cr1901_modern>
Oh?
<cr1901_modern>
Last week I managed to accidentally destroy the flex cable on my Virtual Boy displays, and now I have to send them out to someone who can repair them.
<cr1901_modern>
I had it working briefly, but thought my rework job was fragile. So I kept fixing something that wasn't broke... until it broke for real.
<cr1901_modern>
Wohali: Why are you surprised? I still like DIP chips a lot :P.
<Wohali>
:) just that you'd be interested in the chips but not the games that went with them
<cr1901_modern>
Wohali: Oh, I misunderstood... well, that's a bit complicated
<cr1901_modern>
the only chip I _really_ have nostalgia for is YM2612
<cr1901_modern>
from playing Genesis when I was a kid
<cr1901_modern>
I've always been fascinated w/ how ppl produced sounds w/ it. Sword of Vermilion really comes to mind immediately as a memorable soundtrack
<cr1901_modern>
Later I realized Sound Blaster used a similar chip, but... the first OS I ever used was WIn 3.1. I missed the DOS era.
<cr1901_modern>
I'm not really nostalgic for DOS so much as I like playing w/ the hardware and talking directly to I/O ports
* cr1901_modern
prepares to be branded a heretic
<Ultrasauce>
same really, never owned a game console as a kid
<Ultrasauce>
got nostalgia for the c64/SID cause there was one kicking around but otherwise, eh I just like neat applications of anachronistic electronics
<cr1901_modern>
My interest in YM2151 is because ppl seemed to be more creative w/ instruments on that chip because of its limitations (no samples- FM drums ftw)
<cr1901_modern>
also easier to study b/c everybody already loves the YM2612
<l_oliveira>
funny enough YM2151 and YM2612 are almost the same thing
<l_oliveira>
YM2151 has more channels though
<Wohali>
whitequark: i presume you at least have access to 63/37 and don't have to always deal with horrible rohs solder/etc?
<whitequark>
yes, i always use pb/sn
<Wohali>
thumbs up
<whitequark>
i'm not completely opposed to rohs, i just refuse to use it with a soldering iron
<whitequark>
i have a vapor phase soldering setup
<l_oliveira>
been a funny day here, spent all the day fixing a wreck PC Engine console
<cr1901_modern>
Only game I really want to play on that is Magical Chase
<l_oliveira>
just finished putting it together
<cr1901_modern>
b/c it's so cute it makes me want to throw up :'D
<l_oliveira>
magical chase is awesome indeed
<Wohali>
whitequark: ah, vapor phase. nice. I don't mind RoHS solder in the oven
<l_oliveira>
I like the music
<l_oliveira>
and the 3D effect on the gameplay
<cr1901_modern>
well yea, anything Sakimoto does is great
<Wohali>
heh. i loved my PCEs/etc
<cr1901_modern>
but I just find the premise cute
<Wohali>
cr1901_modern: but my ugly truth: i mostly dislike 8 bit sound chips. i'm old enough to have been heavily influenced first by analogue synths, and was generally appalled at the sound quality of the 8bit stuff.
<Wohali>
nowadays I find them quaint, I guess, but mostly just harsh. FM is the general exception
<cr1901_modern>
Wohali: Ready for my horrible retro opinion? :)
<Wohali>
though i don't really have a fondness for the aliasing you get from the DACs/etc
<Wohali>
go for it
<cr1901_modern>
CGA palettes are objectively awful
<cr1901_modern>
I don't know much about pcjr... IIRC it lacks DMA
<cr1901_modern>
so it doesn't play nice w/ lots of ISA cards
<Wohali>
or better yet tandy color gfx
<l_oliveira>
this PC Engine had a bizarre fault on it
<l_oliveira>
It could play music discs but it would not work with CD-ROMs
<Wohali>
do tell
<Ultrasauce>
Wohali: i plan to integrate opl3/opn2c with a modular synthesizer so hopefully the best of both worlds will be attainable
<Wohali>
Ultrasauce: sounds fun! Shoulnd't be too hard. I can't recall if the DX1 had CV IN/OUT on it...
<l_oliveira>
This morning I went to the CD player menu and saw a button called "FADE OUT", pressed it
<Wohali>
l_oliveira: so the analogue channel was wokring, but the digital didn't?
<l_oliveira>
the thing did not fade out the sound but paused the track after 4 seconds
<l_oliveira>
I checked how the fadder works, there is a Mitsubishi IC which does the volume control
<cr1901_modern>
Does anyone still make "just the keyboard" part of a MIDI synth?
<l_oliveira>
it receives two voltages which control the volume for both audio channels
<cr1901_modern>
so I can connect it to a computer, computer sends the msg to my custom hardware
<cr1901_modern>
and custom hardware interprets MIDI msg
<l_oliveira>
the voltage comes from a large 120 pin VLSI which performs the CD-ROM interface functions
<cr1901_modern>
so I can create a "DX7, except not"
<Ultrasauce>
there are many midi controllers on the market
<l_oliveira>
so the CPU might have been telling the CD interface to lower the volume and it was not receiving the commands
<l_oliveira>
I went around the board traces and found that the trace for the CD interface chip A3 line was broken
<l_oliveira>
so it could not load blocks of data properly from the CD unit hence why it was not booting discs and the fadder register was not being written. Once I mended the trace the thing worked properly
<Wohali>
l_oliveira: nice!
<Wohali>
back later, dinner time
<l_oliveira>
later
<cr1901_modern>
Ultrasauce: What do you define as a MIDI controller
<Ultrasauce>
human interaction goes in, midi messages come out
<cr1901_modern>
I may want to try making music/instruments; the _only_ time I've been remotely successful making music is w/ a keyboard. But I don't need a full fledged one anymore.
<cr1901_modern>
Just something superior to entering notes into a tracker
<Ultrasauce>
i use an oxygen 61
<cr1901_modern>
(sorry I think tracker UIs bite)
<Ultrasauce>
there are also fancier ones with built in arpeggiation, sequencing etc
<Ultrasauce>
but software can fill those roles
<cr1901_modern>
right... guess I'll need to experiment
<cr1901_modern>
Ultrasauce: I may take you up on your idea to sprinkle around 1000 smd resistors just to see if I find 1000 previous missing items
<Ultrasauce>
theres probably diminishing returns
<Ultrasauce>
might need a whole reel
<cr1901_modern>
I can open up a few wormholes at least
<whitequark>
lol
<l_oliveira>
later guys
l_oliveira has quit [Quit: ChatZilla 0.9.92-rdmsoft [XULRunner 35.0.1/20150122214805]]
<ej5>
this is going to go for quite a bit of money, it's the 1989 version of the adlib card.
<Ultrasauce>
complete with scrubbed opl2 lol
<Wohali>
good dindin
<TD-Linux>
lol they scrubbed the dac too?
<fseidel>
can't let people see you're using yamaha parts or they'll draw conclusions about the rest of the board :-P
<whitequark>
lol
<Lord_Nightmare>
ej5: iirc plgdavid has an adlib, not sure what date, but one of the power input tants on it let go spectacularly
<Lord_Nightmare>
i don't believe it damaged the card but just stank horribly
<fseidel>
huh, that's what happened to my buddy's sound blaster
<Lord_Nightmare>
hence if you have an adlib i'd replace the tants on it. (I personally don't think there's anything inherently wrong with tantalum capacitors, so long as you properly overspec them for the voltage they will be using by at LEAST 50-100%
<fseidel>
*flash* + *bang* + "what's that smell???"
<Lord_Nightmare>
so if the tant is filtering a 12v dc input, it should be rated for at least 24v if not more
<Lord_Nightmare>
i'm of the opinion that when used properly tants can last a very long time, significantly longer than electrolytic caps
<Lord_Nightmare>
electrolytics also explode sometimes, but tants are more notorious for shorting
<Lord_Nightmare>
(and for those who have no idea what a 'tant' is, its short for 'dipped tantalum capacitor')
<Lord_Nightmare>
though not all of them are dipped; apple used epoxy coated tantalum capacitors on the quadra 950 motherboard, and despite its age i have never heard of those failing
<fseidel>
yeah, tants are much more reliable assuming you used them correctly
<Lord_Nightmare>
whereas almost every last contemporary apple mainboard with electrolytic caps every last one has failed
<Lord_Nightmare>
the quadra 950 mainboard had spots for both tantalums and electrolytics, but apple always populated the tantalums afaik
<fseidel>
(for those of you who were concerned, said soundblaster had all caps replaced and is doing fine)
<Lord_Nightmare>
there were bad batches of tants made too, iirc kevtris restored two big core memory boards from the 1970s, same model both. one worked fine with no issues, the other the tants kept shorting and then he'd have to track down and replace the shorted one, repeat and a different one shorted, etc
<Lord_Nightmare>
I think he eventually just replaced all of them after the 5th or 6th failed
<Lord_Nightmare>
though i may be wrong. it might have been one specific value where all of them failed, and other values were ok?
<Lord_Nightmare>
tants also have this odd property where they can short and 'self-heal' effectively by burning out the internal short
<Lord_Nightmare>
as long as they don't reach their 'ignition point' from heat through the short
_whitelogger has joined ##yamahasynths
_whitelogger has joined ##yamahasynths
<whitequark>
what's ym633?
<whitequark>
delay line chip controller huh
<whitequark>
do we need ym3413?
<whitequark>
some reverb processor
<whitequark>
ymz284?
<whitequark>
ah that's SSG
<whitequark>
YMF281, i'm guessing yes?
<whitequark>
YMU277?
<whitequark>
or rather YMU251
<whitequark>
YMF286?
<whitequark>
any digital filters?
<whitequark>
YM3807?
<whitequark>
YMZ710? that's SSGP3
<cr1901_modern>
I have not heard of any of these chips before now ._.
<cr1901_modern>
OPK is the package format used for Yamaha synth firmware updates :)
<cr1901_modern>
okay I'll stop now
<cr1901_modern>
Is there an "OPS"?
<whitequark>
YM2128
<whitequark>
well, ok
<whitequark>
i ordered every OP* that was on ebay
<whitequark>
and some that weren't
<cr1901_modern>
Ahh there's OPQ too
<cr1901_modern>
Why the hell did they start at "L" then?
<cr1901_modern>
The chip inside the DX7 is special
<cr1901_modern>
it's actually 2 chips
<cr1901_modern>
"envelope generator" and "everything else"
<whitequark>
huh
<cr1901_modern>
No datasheet... plgdavid knows the register map but doesn't plan on releasing it until he makes the money back from his product
<cr1901_modern>
that emulates those 2 chips
<cr1901_modern>
(which I hope is soon LOL :P)
<cr1901_modern>
whitequark: OPM was the first single chip FM synth from Yamaha. DX7 predates it w/ the "two chip" setup. There are likely other "multichip setups" I'm unaware of.
<cr1901_modern>
Let me know if you can get access to a DX7 you can scrap
<whitequark>
dx7... let's see
<whitequark>
holy shit, $500
<whitequark>
that's DX7S i guess
<whitequark>
TX802 slightly cheaper
* cr1901_modern
is checking something
<cr1901_modern>
DX7 chip is called YM21280
<cr1901_modern>
curiously close to YM2128
<whitequark>
oh that's OPS
<cr1901_modern>
The envelope generator is called "YM21290"
<whitequark>
both of those apparently are OPS
<cr1901_modern>
oh interesting, TIL
<whitequark>
what does pss-390 use?
<cr1901_modern>
Also I made a mistake... YM21290/EGS has the bulk of functionality, YM21280/OPS only has a few registers
<cr1901_modern>
whitequark: Okay just confirming, YM2128/YM21280 are paired w/ YM2129/YM21290 respectively. You'll need both in order to make music
<cr1901_modern>
err you'll need a pair*
<whitequark>
cr1901_modern: also does DX7S ring a bell?
<whitequark>
note the S
<cr1901_modern>
never heard of it
<cr1901_modern>
There's one for sale for a paltry $500
<whitequark>
one 7 or 7s?
<cr1901_modern>
7S
<whitequark>
yeah i can get one for $100
<whitequark>
ok no more
<whitequark>
$240
<cr1901_modern>
nice :'D
<cr1901_modern>
And Idk what pss-390 uses
<whitequark>
looks like dx7s has a better dac
<whitequark>
16 bit instead of 12 bit?
<cr1901_modern>
From what I can tell, DX7 had the most capable chips of the entire Yamaha family, so that wouldn't surprise me
<cr1901_modern>
if the DAC was also superior
<whitequark>
oh hm
<whitequark>
>the DX7s (single), which increased the internal patch memory, considerably improved the implementation of MIDI, and improved output sound fidelity from the mark I's 12-bit floating point DAC + 2 bits of analogue companding (equivalent to 14 bits of dynamic range but not signal-to-noise ratio) to a full linear 15 bits (a 16-bit DAC with the least significant bit tied off, nonfunctional)
<cr1901_modern>
companding ftw
<whitequark>
anyway i guess if someone throws $240 at me i'll get the dx7s and decap
<whitequark>
or $500 and i'll get the dx7
<cr1901_modern>
crowdfund campaign :P
<cr1901_modern>
(not being serious)
<cr1901_modern>
Yea I've no information on pss-390... maybe Lord_Nightmare knows.
<cr1901_modern>
pss series seems to be popular for circuit bending...
<Lord_Nightmare>
whitequark: before you decap any working dx7 stuff, hunt around for people with bad/broken chips
<whitequark>
Lord_Nightmare: i have a better idea
<whitequark>
well sort of
<whitequark>
i talked to the chemist i work with
<whitequark>
i want him to make me a jig for decapping just the epoxy on top of a chip
<Lord_Nightmare>
doesn't that differ by how 'deep' the die is mounted in different chips?
<whitequark>
doesn't matter
<Lord_Nightmare>
i would ask digshadow about this
<whitequark>
i know there are commercial machines that do this
<whitequark>
by using a sort of gasket and a flange that lets you circulate hot sulfuric on top of the chip
<whitequark>
without getting it on most epoxy and leads
<whitequark>
we can do that
<Lord_Nightmare>
ogoun has such a machine, but its in australia... and its broken
<Lord_Nightmare>
the pumps are completely ruined due to acid leaking past failed gaskets, i think
<whitequark>
i don't care about existing designs
<whitequark>
the people i work with on mechanical stuff are very good and charge very reasonable prices
<whitequark>
i'll just have them come up with a new design, i did this before
<whitequark>
the idea is to use standard 316L swagelok stuff for most of the machine
<whitequark>
and do the custom parts from a specialty nickel alloy we have on hand
<whitequark>
that will resist 250 deg sulfuric just fine
<whitequark>
then as it eats through 316L you throw that out and replace it
<whitequark>
it's ridiculous, the chemist i can work with will do me a custom alloy if i request
<whitequark>
at less cost than delivering parts from europe
<cr1901_modern>
There's a viable hobbyist business for custom alloys?
<cr1901_modern>
(let me rephare, the chemist you work with has clients doing looking to do stuff for fun?)
<cr1901_modern>
rephrase* gah
<whitequark>
cr1901_modern: most of his clients are not like me
<whitequark>
they are Serious Russian Businesses
<whitequark>
i think he did work for the military
<whitequark>
but y'know he charges so little for his services that it's absurd to not to use the opportunity
<whitequark>
he does chemistry and welding mostly
<cr1901_modern>
Is he a meatspace friend or just open minded to the work he takes on?
<whitequark>
but knows people who do equally cheap cnc as well as mechanical drafting
<whitequark>
i found him over craigslist
<cr1901_modern>
ahhh cool
<whitequark>
and he will do most everything for enough money
<whitequark>
which is much less money than you would normally expect
<cr1901_modern>
hehe... I like it
<whitequark>
i expect to outfit a lab for decap and etching for the cost of what, one or two used dx7
<whitequark>
for perspective
<whitequark>
he's currently working on a fume hood rated for HF work plus scrubber
<cr1901_modern>
scrubber?
<whitequark>
you'd think it would be an off the shelf part but he thinks making it yourself is cheaper, and so far has not disappointed me
<whitequark>
well like
<whitequark>
you want to remove HF fumes
<whitequark>
but you dont want to put them into atmosphere
<cr1901_modern>
ahhh
<whitequark>
a gas scrubber is something to deactivate the effluent
<cr1901_modern>
Hard to believe that just 8 years ago, if you wanted decap, you'd basically send them to one guy (Dr. Decap) who would use his work equipment during off hours to perform his service. >>
<cr1901_modern>
Now we have multiple ppl who can do decap at home
<whitequark>
decapping is honestly so easy
<whitequark>
i will get my HF today, so we'll see if delayer is as easy or not
<cr1901_modern>
Nice!
<cr1901_modern>
It honestly thought decap was magic when I first heard of it- that ppl could do that type of stuff. Now, not so much. >>
<cr1901_modern>
I don't have any insight as to why there was Dr. Decap, the OPL2 decappers to extract ROM contents (w/ blurry photos), and basically nobody else in the first half of 2010s.
<ValleyBell>
>whitequark: ok, i've ordered, uh, OPL{,[234]}, OPLL{,-P}, OPN{[AB3],2{,-L,-C}}, OPM, SSG{,P3}, MA2 which ones did i miss <-- OPX (YMF271)
<ValleyBell>
not sure how hard that one is to get though
<ValleyBell>
But it's an interesting FM/PCM hybrid chip.
<whitequark>
zero results on ebay and aliexpress
<cr1901_modern>
whitequark: Strictly speaking, SSG isn't an FM synth chip. But it's an AY-3 clone, which I think is important to preserve as well.
<whitequark>
cr1901_modern: yeah i know
<ValleyBell>
The OPX was maybe only used in arcade machines.
<cr1901_modern>
From the era of bayer-dithered CGs :3
<cr1901_modern>
bayer dithering == best dithering
<ValleyBell>
almost everything on the PC-98 is an eroge
* cr1901_modern
knows...
<cr1901_modern>
I'm waiting patiently for new updates on Asemheim :)
<ValleyBell>
But I don't need to play the game in order to enjoy the music, so I don't care.
l_oliveira has joined ##yamahasynths
<whitequark>
ValleyBell: YMF297: Supply Ability:
<whitequark>
22000 Piece/Pieces per Day
<whitequark>
somehow i doubt that
<whitequark>
anyway, do we actually need it?
<cr1901_modern>
I'd file under "would be cute to have, but not essential"
<ValleyBell>
whitequark: No, I don't think we do. Only if you want to have a nice way to offer OPN3 and OPL3 via a web service, similar to your OPL2.
<l_oliveira>
morning
<whitequark>
ValleyBell: but... i could connect an OPN3 and OPL3
<whitequark>
like, separately
<whitequark>
i want to design a PCB that would have ALL of the synths
<whitequark>
actually
<whitequark>
has any features been *removed* from OPL4 compared to earlier OPLs? what about OPN?
<l_oliveira>
OPL3 had CSM synthesis gutted out, that of course carried on to OPL4
<cr1901_modern>
Captiain Speech-something?
<whitequark>
ok, so i'd need at least OPL2 and OPL4, but presumably not OPL1 and OPL3
<l_oliveira>
That's something that was never used outside of Japan
<cr1901_modern>
I imagine YMF297 might have an optimized register layout for having two synths in one... a VGM that used it would have to convert YMF297 writes to the corresponding writes to each individual chip
<cr1901_modern>
it might have extra features too?
<l_oliveira>
These MSX computers with YM2151 modules have actual software which uses CSM on the YM2151 for Japanese language speech
<l_oliveira>
on the ROM by the way
<l_oliveira>
you can make it talk using basic statements
<whitequark>
do we need any of YM2410, YM3422, YM3567, YM2163, YM3558, YMU251, YMF286
<whitequark>
?
<whitequark>
i found all of those on ebay
* cr1901_modern
doesn't know
<l_oliveira>
3526 is the same thing as 3812, just less capable
<l_oliveira>
isn't 2163 just a DRM'd 2151?
<cr1901_modern>
DRM'd in that registers were swapped around?
<ValleyBell>
whitequark: OPL2 should have all features from OPL1 and OPL3 should have all features from OPL4, so OPL2 + OPL4 should be perfect
<whitequark>
ValleyBell: ok, good, less work for me
<ValleyBell>
cr1901_modern: VGMs don't support the YMF297 explicitly. There are separate commands for OPN and OPL chips.
<cr1901_modern>
ahhh okay
<cr1901_modern>
so how is each synth selected in ymf297?
<ValleyBell>
Basically you have one (or two) command types for each chip is supports.
<ValleyBell>
In the Neko Project 2 VGM mod I made, the YMF297 gets logged as YM2610 + YMF262.
<ValleyBell>
*YM2608
<cr1901_modern>
is there control signals for both chips on the pinout, plus a mixer before the DAC
<cr1901_modern>
?
<whitequark>
ValleyBell: what about OPN?
<whitequark>
there's like a zillion of those
<l_oliveira>
OPL2 is good for having the CSM feature. For using the CSM feature you need to interact with the timer
<ValleyBell>
VGM has separate commands for YM2203, YM2608, 2610, 2612 (OPN) and YM3526, 3812, YMF262 and YMF278 each.
<cr1901_modern>
ValleyBell: : I would like to put in a support ticket for GPIO emulation on YM2151 :P
<cr1901_modern>
err GPO*
<cr1901_modern>
in the VGM spec*
<l_oliveira>
OPN are more constant about the features than OPL family, you can toss OPN data on newer chips as is and it will play identically even though VGM has separation for them
<cr1901_modern>
damnit I failed miserably with this joke
<l_oliveira>
even with the chip set into the high features mode
<ValleyBell>
Are the GPIO ports on the YM2151 just specific registers like with the AY8910?
<cr1901_modern>
yes
<ValleyBell>
Then VGMs support those anyway.
<cr1901_modern>
ahhh, gotta find some contrived use for the GPIO ports on YM2151
<ValleyBell>
There is a good chance that the vgm_cmp tool strips them off though. (because they don't affect sound)
<cr1901_modern>
they're used for odds and ends on arcade boards like coin slots and LEDs
<cr1901_modern>
in principle you could also use it as a debug register
<l_oliveira>
Actually X68000 uses the GPIOs on the YM2151 to control things unrelated to sound hehe
<l_oliveira>
one of the bits seem to do something related to the floppy drives
<cr1901_modern>
I like to think there was only a 24 pin package, so the designers were like "f*** it, just add some GPIO"
<cr1901_modern>
would be a bit more interesting if you could actually _read_ the GPIO ports
<ValleyBell>
The "AMD-98" sound board for the PC-98 used the AY's GPIO ports for controlling a 3rd AY8910.
<l_oliveira>
I want to use these bits when I go about making the OKI ADPCM board for MSX using the YM2151 GPIO to control the ADPCM L/R pan
<ValleyBell>
the 1st and 2nd AY chip was accessable directly via I/O ports
<l_oliveira>
I didn't try yet because we have no VGM streams support atm
<cr1901_modern>
ValleyBell: Wait what? There's enough GPIO to do control signal handling on an AY-3?
<l_oliveira>
lol there's an ARDUINO of I/Os in an AY-3-8910
<cr1901_modern>
So they were... using AY-3s as a bastardized version of 65xx PIA or Intel 8255...
<l_oliveira>
two fully bidirectional 8 bit ports
<cr1901_modern>
wow...
<cr1901_modern>
...so it's _literally_ a "PIA that makes sound". Or a "RIOT without the TAM"
<cr1901_modern>
RAM*
<cr1901_modern>
IOTs- I/O, Timer, and Sound
<cr1901_modern>
the superior IoT
<l_oliveira>
AY-3-8910 is a bit awkward to use because it's designed to work with the GIC CP1600 bus
<l_oliveira>
but you just make glue logic and presto
<l_oliveira>
problem solved
<cr1901_modern>
I mean, def not unheard of
<cr1901_modern>
the book I have on 68k has an example of interfacing an Intel-bus based chip (8250) to a 68k
<l_oliveira>
SRAMs are always using intel style control bus but you can use them on motorola style chips just by changing how you use the pins slightly
* cr1901_modern
is afk for a bit
<l_oliveira>
the chips are designed in a way that they just work, I believe write has higher priority than output enable pin so on motorola bus you can just tie output enable as always on and use /WR as R/W pin
<l_oliveira>
(always on = tie it to gnd)
<ej5>
Lord_Nightmare, i don't actually own an original adlib, just my clone. tants are brand new.
<ej5>
also i discovered on my 5150 that the bad tantalums were all the 16v caps on 12v rails. i replaced them with 25v tants.
andlabs has quit [Quit: My MacBook has gone to sleep. ZZZzzz…]
andlabs has joined ##yamahasynths
<Lord_Nightmare>
ej5 that makes perfect sense, ibm didn't overspec them enough
<ej5>
overspec them enough for ~40 years of lifespan, maybe only 25 ;)
<cr1901_modern>
I had a two tantulums die on an old multifunction ISA card that was... barely working. They were on the 12v rail as well if memory serves.
<cr1901_modern>
Replaced them w/ electrolytics because I was lazy- well the card doesn't work for other reasons, but the caps held up fine :)
<fseidel>
motion to call tantalum explosions "tantrums"
<l_oliveira>
old tantalum caps are a hazard. when they explode the hot bits blow far, if they hit flammable material while still hot enough (they get lava-hot when the cap explodes) it can start a fire -_-;