jayb Posted October 30, 2008 Report Share Posted October 30, 2008 Hi there i'm Jay, finished building my MidiboxSid a few weeks ago :) So excited when it arrived i had it built and working! in just a few hours! Its a single 8580, built purely so i can listen to ripped sid files through ASIDXP. However i am very interested in the SID's ability to reproduce digitized sound samples through some sort of hardware glitch, i havn't got a clue how. I have realised that through ASIDXP/SidplayerW2 digitized sounds are not played. Can this glitch only be created while the SID is in the C64 or when sid files are played with a sofware emulator? Is it at all possible for MIOS & MidiboxSid to reproduce these digitized samples?Thanks DSC00177.JPGDSC00176.JPGDSC00177.JPGDSC00176.JPG Quote Link to comment Share on other sites More sharing options...
Labelwhore Posted October 30, 2008 Report Share Posted October 30, 2008 I've read that theres an audio input on the sid chip, but haven't heard a sample so I'm not sure if that's what your speaking of. I'm new to this whole midibox thing so maybe one of the gurus could explain more. Quote Link to comment Share on other sites More sharing options...
Imp Posted October 31, 2008 Report Share Posted October 31, 2008 I remember something about feeding Dc to the Audio in and modulating the volume very fast, so it sounds like a wave with a very low samplerate...but i think it was possible only with the 6581...might be complete BS though... Quote Link to comment Share on other sites More sharing options...
mrcam Posted October 31, 2008 Report Share Posted October 31, 2008 It is briefly explained in the technical details of http://en.wikipedia.org/wiki/MOS_Technology_SID Quote Link to comment Share on other sites More sharing options...
stryd_one Posted October 31, 2008 Report Share Posted October 31, 2008 Nice lookin midibox! MBOTW? Got better pix? Quote Link to comment Share on other sites More sharing options...
nebula Posted October 31, 2008 Report Share Posted October 31, 2008 It is briefly explained in the technical details of http://en.wikipedia.org/wiki/MOS_Technology_SIDThis method was used in the C64 because SID was the only way you could get the processor to interface with the audio output. It could probably be achieved with a PIC, but it would require totally new firmware, since it has little to do with the way the MIDIbox SID application actually manipulates most of the SID registers. This new firmware would also have to store the "samples" on a bankstick.With MIDIbox, there could be far easier ways to get sound output from PIC to your speakers, which would yield far better results, so nobody's really explored SID sample playback. Look for "core synth" in the Wiki - resources would probably be better spent playing back digitized sounds using that method. Quote Link to comment Share on other sites More sharing options...
nebula Posted October 31, 2008 Report Share Posted October 31, 2008 Nice lookin midibox! MBOTW?Seconded Quote Link to comment Share on other sites More sharing options...
jayb Posted October 31, 2008 Author Report Share Posted October 31, 2008 Thanks for the help, there are many games & demo tunes that use sampled music & sounds, along with "standard" SID sounds. Some tunes are fully sampled, created on other music devices then digitized and pumped through the SID, i suppose totally defeating the object of creating music with the SID. But it's fascinating how this almost 25 year old chip handles these samples and adds its own definition to them.Thanks for the compliments on my box, i shall post some better pictures when i am back at home on monday.Heres a classic sample tune from Jeroen Tel, Outrun Europa from Sega 1991. Emulated by SidPlayer, sadly not my real SID :(Outrun Europa - Jeron Tel.mp3Outrun Europa - Jeron Tel.mp3 Quote Link to comment Share on other sites More sharing options...
crisp Posted November 2, 2008 Report Share Posted November 2, 2008 by the way there is also a new way of getting 8-Bit Filtered Sample out of a Stock SID 6581 / 8580 here are some Demos playback best on a Real C64 or the HOXS64 Emulator others wont playback the new Trick well ;)http://noname.c64.org/csdb/release/?id=72563http://noname.c64.org/csdb/release/?id=72678So for the Future I would like to see this new feature in MIDIBOX SID ... yeah an 8BIT Filtered - Sampler without additional Hardware except some RAM / ROM ;) Quote Link to comment Share on other sites More sharing options...
Smithy Posted November 2, 2008 Report Share Posted November 2, 2008 Its a single 8580, built purely so i can listen to ripped sid files through ASIDXP. However i am very interested in the SID's ability to reproduce digitized sound samples through some sort of hardware glitch, i havn't got a clue how. I have realised that through ASIDXP/SidplayerW2 digitized sounds are not played. Have you tried using PSID files? If you download the HVSC package, each digitized sid tune has 2 files, one .SID, and one .PSID.The old version of sidplay will only play digitized samples in PSID files, so it may be the same for ASIDXP.Also, digitized samples will play very quietly on an 8580, a 6581 would be much better...But....In a recent discussion on youtube a guy explained a mod which can be done to make the Digitized Samples louder on the 8580:http://ie.youtube.com/watch?v=pixcjhqLq34It's easy' date=' actually:When the 6581 was designed, a DC offset was deliberately added to the sum signal, so that if the volume register was modified, you could form PCM samples with that (yes, it WAS intended). A decoupling capacitor then got rid of that DC offset.And whoever "optimized" the design for the 8580 didn't know about that, and the DC offset was gone. Solution: Add it again by applying +5V to the audio in through a resistor. Quote Link to comment Share on other sites More sharing options...
jayb Posted November 3, 2008 Author Report Share Posted November 3, 2008 Thanks for the link about the DC offset, but still no luck. It could still just be because i am using an 8580. If i send a completly digitized track the is no MIDI activity at all, except that it sends the track name, so i assume thats ASIDXP.If i send a half digitized track, such as Outrun in my last post, there is MIDI activity & if i turn the volume way up i can just hear the standard SID sounds but not the sampled bits ???Is there anyone else who uses MIOS & SidPlayerMode with a 6581? to confirm if it is the 8580 or not?Heres a few more Pics of the box (and the birds nest that lies within :-[), the back is not quite finished yet.DSC00011.JPGDSC00012.JPGDSC00015.JPGDSC00016.JPGDSC00011.JPGDSC00012.JPGDSC00015.JPGDSC00016.JPG Quote Link to comment Share on other sites More sharing options...
286 Posted November 3, 2008 Report Share Posted November 3, 2008 If i send a completly digitized track the is no MIDI activity at all, except that it sends the track name, so i assume thats ASIDXP.If i send a half digitized track, such as Outrun in my last post, there is MIDI activity & if i turn the volume way up i can just hear the standard SID sounds but not the sampled bits ???Is there anyone else who uses MIOS & SidPlayerMode with a 6581? to confirm if it is the 8580 or not?I use ASIDXP with my 6581. No samples are played. Also, ASIDXP only plays PSID files and not RSID files. (Both can have .sid as fileformat name) Quote Link to comment Share on other sites More sharing options...
Smithy Posted November 3, 2008 Report Share Posted November 3, 2008 Thanks for the link about the DC offset, but still no luck. It could still just be because i am using an 8580. Ah yeah, the dc offset mod wouldnt solve that issue.I just kinda meant if you ever do play samples with the 8580, that it would be worth doing to boost the volume. :) Also, ASIDXP only plays PSID files and not RSID files. (Both can have .sid as fileformat name)I didnt think of that! The HVSC seperates has both extensions seperate which is great. Quote Link to comment Share on other sites More sharing options...
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