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kulor
Account closed
Registered: Nov 2013
Posts: 3 |
Goattracker on a real C64
I've been looking all over trying to find the answer to this, but to no avail.
I'm pretty new to C64 composing, and I finally have a real C64 to render tunes out on. The issue is, as expected, the filtering sounds completely different in GT compared to the real deal.
I really like GT and would prefer to use it as my tracker instead of learning some native platform tracker. What I'd like to do is use some native program on the C64 to figure out filter values to plug into GT. I don't care if it sounds different in GT, as long as I can get the same sound when I play back the SID on my real C64.
The issue is, GT seems to use some 8-bit value for filter cutoff, whereas the C64 seems to actually use more bits for its cutoff registers (11-bit IIRC?).
Is there a native program that uses GT-style 8-bit values for filter cutoff, or at the very least could anyone provide some info on how the GT values are plugged into the 11-bit cutoff register?
Any help is appreciated, and apologies in advance for any technical details that I butchered! |
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Saxxon
Account closed
Registered: Mar 2009
Posts: 12 |
The reason why 8-bit values are used instead of 11-bit values is because the other 3 bits wouldn't make much of an audible difference, I suspect. Just the most significant 8 bits are used. In this case it's a range of 2048 values in steps of 8. Plenty accurate for a song.
Filters are going to sound way different even between different models of C64. I have some songs that sound fantastic in emulation, but my 64's filters are so dark that low pass makes things near inaudible.
If you are looking for something *similar* to GoatTracker, I think NinjaTracker should be close. I haven't used it myself, but it's from the same group I think :) They even have a GoatTracker -> NinjaTracker conversion tool, how about that?
http://cadaver.homeftp.net/tools.htm |
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CreaMD
Registered: Dec 2001
Posts: 3034 |
If Filter sounds totally different, chance is that you use different SID version (emulation) in GT and differen SID (chip) version on real machine. There art two major versions of SID. 6581 SID (used in original C64 breadbox) and 8580 SID (used in new C64 machines). I reccomend to solve this mystery first. |
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kulor
Account closed
Registered: Nov 2013
Posts: 3 |
Saxxon: So close! What I'd really need is a NinjaTracker > GT converter. I'm well aware how the filters vary from C64 to C64, so what I'm basically trying to do is make a song specifically for my piece of hardware so that I can make it sound perfect and render it out on that particular one. I'll play around with discarding the 3 least significant bits in filter stuff on native programs and see how it matches up to what GT does.
CreaMD: Mine's a 6581, couldn't tell you the specific revision though. The distortion is the same, I'm just trying to tame the cutoff values, if that makes sense. |
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Linus
Registered: Jun 2004
Posts: 638 |
There is a Goattracker tweak utility that runs natively and is able to load .sng files. Within that utility you are able to alter table- and instrument data to match the filter behaviour of your machine.
Grab it here: http://cadaver.homeftp.net/tools/tweak2.zip |
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onebitman
Registered: Nov 2002
Posts: 47 |
you can slave your c64 to goattracker via RS232 connection to the userport, then you instantly hear what you get. all you need is a cheap nokia CA-42 cable and a userport connector and a little bit of soldering skill. the cable must not be original nokia - some cheap chinese fakes of the cable have issues in win8, but there is a workaround to install it. atm i have a bunch of these cables flying around, if somebody needs a finished cable msg me (i give them away for material price +shipping)! software is by the same guy that did the "fakehardsid" thing on csdb, but this is a new serial version: http://dawork.synchronus.de/filez/serclone.zip --- also this RS232 cable can be used for datatransfer and for playing back tunes with sidplay 1.0 |
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Hein
Registered: Apr 2004
Posts: 933 |
Possibly some native trackers that don't use 11 bits filters have the 3 bits initialized on either %111 or %000, dunno about GT init.
I remember some editor to poke the MSB value directly to the 3 lower bits too.
I doubt it would make a difference on a 6581 either way, though. You might aswell use a high end tool to master your rendition, my 6581 will never sound the way you intended it. |
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Mr.Ammo
Account closed
Registered: Oct 2002
Posts: 228 |
I believe SID Wizard has a conversion utility called sng2swm. Don't know if it's good enough, but you could try and find out. |
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tlr
Registered: Sep 2003
Posts: 1703 |
Quote: you can slave your c64 to goattracker via RS232 connection to the userport, then you instantly hear what you get. all you need is a cheap nokia CA-42 cable and a userport connector and a little bit of soldering skill. the cable must not be original nokia - some cheap chinese fakes of the cable have issues in win8, but there is a workaround to install it. atm i have a bunch of these cables flying around, if somebody needs a finished cable msg me (i give them away for material price +shipping)! software is by the same guy that did the "fakehardsid" thing on csdb, but this is a new serial version: http://dawork.synchronus.de/filez/serclone.zip --- also this RS232 cable can be used for datatransfer and for playing back tunes with sidplay 1.0
Very nice! Beautiful implementation of 115k2. |
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kulor
Account closed
Registered: Nov 2013
Posts: 3 |
Lynus: I'm awestruck, this is precisely what I was looking for! I was able to jump in and start editing stuff in less than 10 minutes too, amazing. Couldn't have asked for a better response.
Thanks for the help, guys! |
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Linus
Registered: Jun 2004
Posts: 638 |
You're welcome! Happy tracking. |
