I just received these ... What should I do with them ?

I just received these ... What should I do with them ?
by on (#92661)
Image

First obvious thing I'll try is make a dupe of Lagrange Point ... lol


edit: Repaired image link.

by on (#92665)
Try and make a VRCVII dev cart to experiment with the mapper's awesome features and sound, and use it to design custom chiptunes or an advanced homebrew! :D

by on (#92670)
Send some of them to a lab to be cloned. ;) Make PCBs to use the rest.

by on (#92671)
OMG! PM me how much you've got'em :shock:

by on (#92680)
I'd say decap them and study the blueprints so emulation accuracy can be improved.

by on (#92686)
ah, I am jealous now, these chips are so nice and new! :P

But how this can be possible? They are not a clone chip and seems original but why they are still unused?! :shock:

by on (#92687)
Are they pulls or NOS? If so, got a pallet of them hopefully? :P

by on (#92688)
3gengames wrote:
Are they pulls or NOS? If so, got a pallet of them hopefully? :P


NOS, only have the 4 units pictured. I looked for other VRC chips but could not find any. I was originally looking for the K051649 (MSX SCC) but the guy had these... So I got them. Asked for the K053329 (VRC VI) too but there were none.

by on (#92739)
What does "NOS" mean? ('non-opened stock' ??)

by on (#92741)
clueless wrote:
What does "NOS" mean? ('non-opened stock' ??)

Perhaps Non Used Stock ?

by on (#92742)
It means "new original stock"

by on (#92743)
Jeroen wrote:
It means "new original stock"


Thanks :)

by on (#92747)
I've heard it being referred to as New-Old Stock. Oldass things that have not been used.

by on (#92748)
Whatever it means exactly. It basicly means that they're new unused original parts.

by on (#92767)
+1 for New Old Stock

by on (#92779)
But they are not from the same box - date codes are different :?

by on (#94309)
Now I finally got some sound out of one of these chips...

As Kevtris mentioned on his document for VRC7 it does work exactly as a YM2413. The only difference is that there's no percussion output and a few of the internal voices are different (probably to accommodate the fact that it miss the percussion pin on the package.

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"schematics" on how to make it operate like a YM2413 will follow in a short while (once I make the block representation for the chip on BVPE3)...

If anyone is curious, I just wired it so it would see only $9010/$9030 writes, connected the "A5" of the would be Famicom to the MSX A0,M2 to the /RESET and wired /WR and /CS to the original YM2413 connector. The chip is running from a 3.57 mhz quartz crystal instead of a ceramic resonator.

Sound is slightly different than that of a normal YM2413 due to the subtle internal rom differences and lack of percussion.

edit: Repaired picture links.

by on (#94364)
Requesting clear photo of PCB, where is PCB with VRC7 connected.

by on (#94368)
80sFREAK wrote:
Requesting clear photo of PCB, where is PCB with VRC7 connected.


This one ?
Image

Or the one with the VRC7 chip itself ?

edit: Repaired picture links.

by on (#94396)
No, no, this one. Nice! :D Hows YM2203 sounds? I have one, but untested yet(desoldered from sound card looking board).

by on (#94397)
YM2203 is a half channels of YM2612 (Sega Genesis) with minor differences, they are software compatible for the most part and sounds the same.

by on (#94406)
Shiru wrote:
YM2203 is a half channels of YM2612 (Sega Genesis) with minor differences, they are software compatible for the most part and sounds the same.


Actually YM2203 is the original chip that started the OPN family, which is in turn a merge of a "cheapened" OPM (YM2151) core with a SSG (YM2149F which is Yamaha's own version of the legendary AY-3-8910 sound chip from the Intellivision)...

The chip on the Mega Drive in particular is two YM2203 slapped together with some additional interconnection to allow for 4-op voices using the 2 FM cores simultaneously. Ah and SSG stuff got mostly removed keeping only the envelope registers. I suppose, as these are used by the FM synth to enhance the chip features.

There's even tools to translate/convert patches from OPM to OPN or the inverse ... (edit: oy I forgot, you made the tools, Shiru XD my bad)

The VRC7 is a member of the OPL family in the other side, so it uses YM3526 (OPL)/YM3812(OPL2) patches/tones.

The board I posted pictures from contains also an Konami 051649 (SCC) along with it's resistor ladder DAC (051650) allowing for single slot music playback on a MSX computer using Japanese MML compilers such as MGSEL, MuSICA or Performer OPX...

Finally these are pictures of the bottom of the board with the VRC7. The blue board is just a mechanical adapter to allow the connection of a FAKE OPLL (U3567) to a real OPLL connector.

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Image

I used a gutted 27512 EPROM "body" as pin carrier for the adapter part as one can notice in the pictures.

Edit 2: I actually fixed the oscillator circuit from the older picture, moved one 27PF and 1Mohm resistors from bottom of the board to the permanent position on top. Resistor is behind the quartz oscillator.

edit: yep... I'm tired of typing the same thing over and over ...

by on (#94407)
I should only note that SSG part of YM2203 and SSG-EG registers of YM2203 and YM2612 are separate things that only share the same name. I.e. YM2203 SSG part has a single envelope generator (just like YM2149F), but it does not interfere with 3*4 SSG-EG generators of the FM part, they could be used simultaneously. I guess the SSG-EG registers were named so just because they function in a similar way.

There were long time doubts that the SSG-EG registers are not function properly or at all in (some) YM2612's or its integrated counterparts, because of the Sega's official docs, but it seems that in fact they are always there and works just like in 2203.

by on (#94409)
80sFREAK wrote:
No, no, this one. Nice! :D Hows YM2203 sounds? I have one, but untested yet(desoldered from sound card looking board).


Make sure you extract the YM3014 chip too (8 pin DIP) or else you will be stuck with SSG only sounds... ;) Edit: My board has the YM3014 assembled under the YM2203 inside the socket middle empty space. Also, there's a address decoder chip under the Intel flashrom. The flashrom has the MSX BASIC driver for OPLL (MSX-MUSIC).

After I'm done playing with the VRC chips I'll play with this little fella on the MSX ...

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(This board is tested and produces music correctly if the chip receives commands)

edit: dang Picasa stop breaking my links

by on (#94539)
rainwarrior kindly uploaded a recording from the VRC7 chip operating in a MSX computer in parallel to a real YM2413:


http://dl.dropbox.com/u/883356/VRC7_and_YM2413.ogg

by on (#94797)
What's the song used? It sounds pretty nifty. :D

by on (#94810)
l_oliveira wrote:
rainwarrior kindly uploaded a recording from the VRC7 chip operating in a MSX computer in parallel to a real YM2413:
http://dl.dropbox.com/u/883356/VRC7_and_YM2413.ogg
Came as rainbow.

Well, now i have more points to use YM2413

by on (#94817)
another sample:

http://wiki.nesdev.com/w/index.php/File ... _MGSEL.ogg

This one is more suitable for compare as it has no reverberation/echo and only melodic output from YM2413 is connected.

by on (#94858)
Almost done with this:

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Now to build the RAM backup control circuitry and the audio mixing hardware. ;)

edit: so many broken links ... so little patience ...

by on (#94864)
And finally, the whole point of all this:


Image


http://wiki.nesdev.com/w/index.php/File:VRC7_and_YM2413_on_FAMICOM_LP_intro.ogg
Re: I just received these ... What should I do with them ?
by on (#136177)
So... what is exact the difference apart from no rythm in VRC7?
Re: I just received these ... What should I do with them ?
by on (#136179)
The VRC7 has different patch presets compared to the YM2413. That's the only difference I know of, anyway.