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
<ValleyBell>
It's an Arduino Leonardo, which acts as USB-MIDI device with 4 ports. Data is converted to RS232 and goes into the MU128's "To-Host" input.
emeb has joined ##yamahasynths
<Lord_Nightmare>
ej5: where can i order a pixel pooper? I'd ask what system is it for, but given the name i'm not sure that matters.
andlabs has quit [Quit: My MacBook has gone to sleep. ZZZzzz…]
andlabs has joined ##yamahasynths
andlabs has quit [Ping timeout: 260 seconds]
andlabs has joined ##yamahasynths
<ej5>
Lord_Nightmare, if you really want one i could probably send one to you after i get it up and running
<ej5>
in general i just release the designs and it is up to other people to go build/fabricate them
HXLNT has joined ##yamahasynths
<cr1901_modern>
Yaaay, glad you could make it HXLNT :)
<HXLNT>
hi hi~
<cr1901_modern>
Lemme introduce you to some ppl you may know
<KitsuWhooa>
probably not the best idea to mass highlight people, but hi :p
<KitsuWhooa>
Also, I'm not really a vgm ripper :p
<HXLNT>
Recognize some other familiar names from twitter, too.
<HXLNT>
It was suggested I pop by to see if anyone has an ideas about an unknown game console sound chip I've been rabbit-holing on.
<cr1901_modern>
^Fair enough re: mass highlight, but this is the reason I did it. I don't want to waste ppl's time :P
<cr1901_modern>
It's part of FM towns and CASIO Loopy?
<ej5>
reminds me of the time i pasted %007 into an general chat IRC channel, back in the 90s
<HXLNT>
Hoping to get some ideas for cracking audio on the Casio Loopy. Looking at the motherboard, I think I've ID'd the audio chip as a Ricoh RH5C350.
<HXLNT>
It doesn't say Ricoh on it, but the Rx5Cxxx naming tipped me off. Plus, I'd say the sound is similar to the FM Towns.
<HXLNT>
However, no datasheet, different pinout, and no Loopy emulator. So thinking on the best way to make progress.
<cr1901_modern>
I literally get 0 results from Google... nice :o!
<HXLNT>
Haha, yeah, I already hit datasheets.com, ebay, etc.
<KitsuWhooa>
the Ricoh chip is RF5C...
<KitsuWhooa>
so hmmm
<HXLNT>
Yeah, I think this is an undocumented chip that Ricoh made custom for Casio.
<cr1901_modern>
My guess is that the chip is similar to RF5C68/the Sega CD chip
<KitsuWhooa>
Wild guess, but check if there's PSRAM around it
<cr1901_modern>
Find the pinout, including voltage rails, solder one of the RF5C60s to a breakout board, apply voltage. If no smoke, continue :)
<KitsuWhooa>
then maybe not
<cr1901_modern>
ahhh, hrm
<KitsuWhooa>
your best bet is to follow the chip that outputs the audio, yeah
<KitsuWhooa>
it might be intergrated in the other asic
<KitsuWhooa>
as that's the one that has the memory
<cr1901_modern>
So RF5C60 is a port expander
<cr1901_modern>
Based on proximity to the 6379 serial DAC, I think the Ricoh RH5C350 is outputting the audio
<cr1901_modern>
But of course trace conns w/ multimeter :D
<KitsuWhooa>
cr1901_modern: which one is the DAC?
<cr1901_modern>
IC251 silkscreen
<cr1901_modern>
top right corner
<KitsuWhooa>
Ah I see
<KitsuWhooa>
completely missed that one
<cr1901_modern>
HXLNT: Depending on how much effort you want to go through to start with, you could get some results by capturing the DAC input directly :D
<cr1901_modern>
HXLNT: Oh, to summarize, RF5C60 is a port expander
<cr1901_modern>
not a sound chip
<HXLNT>
Yeah, I think right around the time I got kicked, I was lamenting that the Ricoh chip on the Loopy might just be handling the controller and/or printer.
<HXLNT>
Despite the totally reassuring "this might be the sound chip
<HXLNT>
" message in the Loopy .cpp file in the MAME repo
<HXLNT>
lol
<cr1901_modern>
I think it is the sound chip, but I want continuity tests done w/ multimeter
<cr1901_modern>
the chip to the right of the suspected sound chip is a DAC
<HXLNT>
Yup, that's my next step :p
<HXLNT>
Yeahhhh
<cr1901_modern>
if that (serial!) DAC is connected to that suspected chip, then I think we can safely say it's the sound chip
<HXLNT>
I really appreciate all the tips and ideas. Excited for baby girl's first reverse engineering project on something that isn't from the 1980s!
<HXLNT>
What's the significance of it being a serial DAC?
<cr1901_modern>
I2S is popular sound format, which is also a serial protocol
<cr1901_modern>
so if you're converting a serial stream to analog, that's a hint to me that you're dealing w/ a sound stream
<HXLNT>
Ohhh, this is great to know! I wasn't aware of I2S.
<HXLNT>
Pulling up docs now :)
<HXLNT>
I'm learning so much today <3
<cr1901_modern>
Btw, ty for taking me up on the offer to try the channel out :D. I know IRC is getting long in the tooth.
<HXLNT>
It's taking me back, tbh.
<cr1901_modern>
The good parts, I hope
<HXLNT>
Teen days of sharing MP3s over Direct Connect in a #warez channel
<cr1901_modern>
I was big into anime fansubs in the late 2000s- 2008-2009-ish.
<HXLNT>
Oh, same, but maybe 10 years earlier, so a way teeny-tiny "scene" :D
<HXLNT>
Outing myself as Ancient Millennial
<cr1901_modern>
I got started w/ IRC and stuff rather late. Though I do have a fansub of Tanjou Debut from the 90s. Hardsub 320x240
<HXLNT>
It was all VHS
<HXLNT>
God, I remember leaving downloads running all night to get anime INTRO SEQUENCES at that resolution
<HXLNT>
RIP RealPlayer
<cr1901_modern>
Bahahaha... RIP 56k modem
<HXLNT>
More like 36.6
<HXLNT>
In the time of 56K
<HXLNT>
I also had to be supervised when I was on the computer
<cr1901_modern>
I'm waiting for a domesday86-like project to tap into a VCR's raw output and capture VHS from those signals
<cr1901_modern>
I had the password to the computer changed a number of times b/c I kept breaking the rules
<HXLNT>
Tsk tsk
* cr1901_modern
... isn't all that sorry?
<cr1901_modern>
HXLNT: Right, when she's around... you may want to talk to whitequark and see if her Glasgow project is right for you. She's already used it to play YM chips and stream the results in realtime. You could probably apply it to your RE-capades.
<HXLNT>
Cool... just found the repo for it; will check it out.
<HXLNT>
I'mma go idle for a bit and eat some lunch. Nice chatting w/ y'all!
<cr1901_modern>
Have fun :D!
HXLNT has quit [Read error: Connection reset by peer]
HXLNT has joined ##yamahasynths
<cr1901_modern>
ej5: What is %007... beep sound?
<ej5>
yeah
<cr1901_modern>
Also, is the NTSC done inside the FPGA?
<cr1901_modern>
for the video card?
cr1901_modern has quit [Quit: Leaving.]
cr1901_modern has joined ##yamahasynths
<Stilett0>
HXLNT: stay in channel please, I suspect Lord_Nightmare may have some hypotheses for you after the weekend is over here :)
<Stilett0>
and feel free to send MAME any documentation or emulation fixes via Github pull request :)