Rybags Posted March 31, 2018 Share Posted March 31, 2018 No... the preferred way would be a digital capture oscilloscope. But I've only got a CRO. Next best would be capture by PC card at a high sample rate. Quote Link to comment Share on other sites More sharing options...
Foebane Posted March 31, 2018 Share Posted March 31, 2018 https://brokenbytes.blogspot.com/2018/03/a-48khz-digital-music-player-for.html FAKE! 1 Quote Link to comment Share on other sites More sharing options...
Sheddy Posted March 31, 2018 Share Posted March 31, 2018 Yep, if it was linear, the maximum volume would be 15 + 15 + 15 + 15 (as Rybags said, 4bit + 4bit + 4bit + 4bit) but in reality it is even less than 60 Jim Slide may approach 6 bit, not 7 as I had put Quote Link to comment Share on other sites More sharing options...
+CharlieChaplin Posted March 31, 2018 Share Posted March 31, 2018 (edited) Afaik, Pokey cannot playback samples / digis / MODs / etc. with 8Bit resolution (only 4Bit or with tricks up to 6Bits). Thats why they invented the Covox enhancement in the 90s. It is a simple thing to add 8Bit digi playback to the A8. There were single Covox devices (selfmade ones and some commercially sold by Lotharek) and several enhancements that included a Covox (e.g. Simple-Stereo by Candle which is still available at Lotharek's shop, IDE+ version S, RAM-320XE, etc.). Covox_Info.zip Edited March 31, 2018 by CharlieChaplin 2 Quote Link to comment Share on other sites More sharing options...
emkay Posted March 31, 2018 Share Posted March 31, 2018 Yep, if it was linear, the maximum volume would be 15 + 15 + 15 + 15 (as Rybags said, 4bit + 4bit + 4bit + 4bit) but in reality it is even less than 60 Jim Slide may approach 6 bit, not 7 as I had put Never checked it. But it could be interesting to have a look at why the plain volume does just add , while the generators add in a non linear way. Quote Link to comment Share on other sites More sharing options...
Sheddy Posted April 1, 2018 Share Posted April 1, 2018 Nope, plain volume is non linear too. Volume never gets close to 60. Same as generators. I need an idiot guide to pulse width modulation. How can average volume of pulse over same time be more finely controlled than fastest 4 bit direct volume writes? I didn't understand Phaerons code when I had a quick look. Obviously I'm missing something fundamental Quote Link to comment Share on other sites More sharing options...
Rybags Posted April 1, 2018 Share Posted April 1, 2018 With PWM the granularity is a single cycle within whatever the carrier frequency is - generally you want the carrier frequency to be as high as possible but of course since our machine is a bit slow there's limitations. So, if e.g. you were to use 2 scanlines for PWM your carrier frequency would be just under 8 KHz and you'd have 228 graduations which is almost equivalent to 8-bit sound quality. But of course hitting the exact cycle isn't always possible so there'd be a bit of loss of precision there but the main problem is that we get an unfiltered and undesirable 8 KHz carrier noise. The whole philosophy of PWM is that you're providing "full voltage" for a fraction of the overall timeframe (=duty cycle). It's used in the real world for all sorts of things including audio playback, and many cheap DC to AC inverters use it (generally at a v-high frequency of 20-40 KHz). 2 Quote Link to comment Share on other sites More sharing options...
Sheddy Posted April 1, 2018 Share Posted April 1, 2018 thanks Rybags. Hmm, I'll still have to think that through a bit, along with what Xuel wrote earlier. Quote Link to comment Share on other sites More sharing options...
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