Re: Sound Bank rom dumps - how are made?
Posted on 2020-09-25, 19:29
@mkarcher : thank, that clarifies a lot of the questions I had.
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-25, 17:33
@Cloudschatze thanks for another idea about the potential encoding/packing/compression they are using. in the attachment here: https://www.vogons.org/viewtopic.php?p=896369#p896369 in "ramdump.bin" (after "CM-64/32L.ME" data sequence), there are few unpacked samples. I am working on finding the data …
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-25, 12:38
made a little more progress - based on my analysis it seems "block 2" is encrypted with "mirror image" of the "block 1" key (i am very confident about that) - "vscdecv3.c" taking that into account is attached. unfortunately, that's not all - it seems after decryption the wave data are unpacked ( …
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-25, 07:44
found another key fact about point 2. here: https://www.vogons.org/viewtopic.php?p=896282#p896282 or in other words about "header bytes offset 0x18 to 0x1f" : they seem that important for Roland that they made great effort even between 2 consecutive versions 3.2 Retail and 3.23 Retail to conceal …
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-24, 19:49
and guess what - the point at which the encryption algorithm changes is defined in the File Header of the Sound Bank at offset 0x28 to 0x2a. So, 3 bytes from the header discovered what they are, the hard way...
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-24, 18:37
There is no doubt now (at least to me) that after "CM-64/32L.ME" text is decrypred, the Sound samples begin (i.e. definitions of the instruments end and the actual PCM/WAV data begins) and the sound samples are encrypted with new keys/algorithm. Please, check the attachment and tell me your opinion: …
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-24, 18:02
I believe I am up to something and I don't believe it's just a coincidence and that it happens immediately after "CM-64/32L.ME" text is decrypred. So, I am testing with "vsc55.dat" from VSC 3.x - both old "sm0n" and my "vscdec" generate the same file output, but after 422588 bytes and exactly after …
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-24, 14:15
In theory, the Roland PCM data is mu-law companded. many thanks, that could explain it... let me first finish what i mentioned in the "[edit]" of my previous post - just to double-check and make sure the decryption works properly on the whole bank and there are no some blocks of the bank encrypted …
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-24, 12:02
I made very simple new attack - I wonder how I didn't think about it earlier (I guess my lack of experience working on such tasks), but no one else here suggested it either... So, I just dump the RAM - after all the Sound bank has to be loaded to the RAM and yes it's loaded unencrpyted, i.e. …
Re: DDMA and PCPCI for Low IQ Individuals (Me included)
Posted on 2020-09-24, 10:35
I've started my Live cards successfully on my motherboards with ICH5, VT8235, VT8237, ICH4, SiS964 southbrigdes. What is this if not PCI DDMA? How can you explain it? All of those, I guess, have to be "vendor specific solutions (some of them software emulations and not even hardware in nature)" as …
Re: Yamaha YMF7x4 Guide
Posted on 2020-09-24, 10:23
@Oerg866 I don't believe VT8237x has DDMA, because you can read here: https://www.vogons.org/viewtopic.php?t=24769 On VT8237x, AFAIK only ESS Solo-1's DOS driver can still work in most scenarios. and I read here: https://www.vogons.org/viewtopic.php?p=802285#p802285 ESS Solo has its own i8237-style …
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-24, 09:39
hmm, i found very interesting thread in another forum about reverse-engineering Yamaha TG100. So, after they acquired the raw sound bank data, they did: sox -t raw -e signed-integer -b 24 -c 1 -r 8000 bank.raw bank.wav and indeed you can play the wav file and you can hear the sound samples one after …
Re: Sound Bank rom dumps - how are made?
Posted on 2020-09-24, 05:30
Isn't there anything written on the chip already which may possibly be used to identify it in a Yamaha parts catalog? in case of Yamaha SW60XG/DB60 ("db60" as far as i know is identical to what I have - "NEC XR385") here: https://www.vogons.org/viewtopic.php?p=356307#p356307 'jwt27' described them …
Re: Sound Bank rom dumps - how are made?
Posted on 2020-09-24, 04:53
I found interesting Twitter thread of how Creative CT1351V202 ROM/firmware was dumped: https://twitter.com/TubeTimeUS/status/1137554976257929217 it's fascinating, but away over my skills - the chip top was "decapsulated" then with microscope and some jig i don't recognize (consisting of 44-PLCC to …
Re: Sound Bank rom dumps - how are made?
Posted on 2020-09-24, 04:17
OK, but in my case how I can ID what type of EPROM are those "Yamaha" branded chips - I mean the programmer and the adapter are probably dependent on the exact type - which pins are data, which are power supply pins, etc?
Sound Bank rom dumps - how are made?
Posted on 2020-09-23, 18:34
hi All, I wonder how Sound Bank ROM dumps are made, for example here: https://www.vogons.org/viewtopic.php?p=419332#p419332 'jwt27 ' said: "I dumped the DB60XG's firmware ROM a (long) while ago" that is very similar hardware to "NEC XR385" board, which I have, but cannot find any information how …
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-23, 14:55
just for fun used SheepShaver to install the Macintosh version - interesting, even VSC 3.x retail distribution comes with VSC 2.1 for Macintosh. So, that makes the only known version for Mac to be 2.1. the sound bank in Mac is called "VscStdSet", but it's actually "vsc88" from VSC 2.x for Windows. …
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-23, 07:32
OMG, while looking to make more sense of the Sound bank unencrypted header, I noticed another flaw in Roland encryption - due to the nature of the data and the encryption algorithm, as a side effect, the encryption key gets stored in plain text in the encrypted data section at offset 0x50 in the …
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-23, 06:30
Here is the list of GS standard drum sets (later SC devices of course expanded it) 0 Standard Kit 8 Room Kit 16 Power Kit 24 Electronic Kit 25 TR-808 /909 Kit 32 Jazz Kit 40 Brush Kit 48 Orchestra Kit 56 Sound FX Kit 127 CM-64/CM-32L Many thanks, that fully explains it - basically both " CM-64/CM- …
Re: About Roland Virtual Sound Canvas 3
Posted on 2020-09-23, 05:49
likely that you have found the reference text for the GS standard TR-808/909 drum kit that can be found on any SC devices starting from SC-55 at channel 10/Program 25. So no full emulation , just samples for a drum kit. I see, I really hope, someone that actually have good knowledge about those …
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