The C64 has a volume register. It's 4 bit, so 16 levels. Changing the volume using this register (on a 6581) creates a DC offset. So when you change the volume crazy fast, you can abuse the DC offset, and you can use samples to change the volume, adding a 4-bit channel for samples
Why didn't you use your tool on this one; it doesn't work with samples? I think it'd be interesting to see a visualization of Robocop 3 with Sidvis, since I don't like that visualization that Rolf made! The waves there have a strange filter; they are very messy and don't look like square waves. X-(
These are older videos. I'm still working on sidvis, and will be making an announcement once I've got it to a state I'm more happy with. RoboCop 3 uses the SID's filter for equalization, so the weird looking waves are actually a part of the tune.
@@acrouzet Keep up the good work. I appreciate this information, but channel @u64 made an osci. view of Robocop 3 with clean waves (you can even see clearly the transition between sawtooth and square!), so what happened there? Could you check? He was also developing a tool, but with some bugs and lags.
I don't know the details of his tool but the .sid file clearly has low-pass & high-pass filtering on all 3 channels throughout the entire track. I assume this person either disabled the filter, or used an inaccurate emulator.
![Tim Follin - "Ghouls 'n' Ghosts (C64)" Full Soundtrack [Improved Oscilloscope View]](http://i.ytimg.com/vi/T2BhAe5Ec6s/mqdefault.jpg)
![Tim Follin - "Ghouls 'n' Ghosts (C64)" Full Soundtrack [Improved Oscilloscope View]](/img/tr.png)
orchestra hit wuowowow
you just beat me to it, that was exactly what i was planning to make lol
nice video tho' :)
I feel like this is made by Jeroen Tel
The orch hit sample is used in out run, which Jeroen composed
didn't the C64 have 3 channels and only use saw, sine, square and noise?
idk the specifics but devs back then found an exploit to add samples.
@@AceGetChippyWitIt oh
The C64 has a volume register. It's 4 bit, so 16 levels. Changing the volume using this register (on a 6581) creates a DC offset. So when you change the volume crazy fast, you can abuse the DC offset, and you can use samples to change the volume, adding a 4-bit channel for samples
Why didn't you use your tool on this one; it doesn't work with samples? I think it'd be interesting to see a visualization of Robocop 3 with Sidvis, since I don't like that visualization that Rolf made! The waves there have a strange filter; they are very messy and don't look like square waves. X-(
These are older videos. I'm still working on sidvis, and will be making an announcement once I've got it to a state I'm more happy with.
RoboCop 3 uses the SID's filter for equalization, so the weird looking waves are actually a part of the tune.
@@acrouzet Keep up the good work. I appreciate this information, but channel @u64 made an osci. view of Robocop 3 with clean waves (you can even see clearly the transition between sawtooth and square!), so what happened there? Could you check? He was also developing a tool, but with some bugs and lags.
I don't know the details of his tool but the .sid file clearly has low-pass & high-pass filtering on all 3 channels throughout the entire track. I assume this person either disabled the filter, or used an inaccurate emulator.