xxl Posted November 20, 2008 Share Posted November 20, 2008 hi, YERZMYEY/HOOY-PROGRAM from ZX-Spectrum scene send me some BEEP music. i rewrite 'music studio' player from zx spectrum and music from zx can be played on GTIA, dont play it on emulator (emulator has bug), mp3 recorded on real atari. http://www.ghnet.pl/~pin/atari_beep/part4.mp3 http://atari.pl/part4.xex - only for test. http://www.ghnet.com.pl/~pin/atari_beep/bee2a.mp3 http://www.ghnet.pl/~pin/atari_beep/beeporgy.mp3 Quote Link to comment Share on other sites More sharing options...
Chrodegang Posted November 20, 2008 Share Posted November 20, 2008 music from zx can be played on GTIA GTIA? Quote Link to comment Share on other sites More sharing options...
xxl Posted November 20, 2008 Author Share Posted November 20, 2008 yes, GTIA music, (not POKEY) Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted November 20, 2008 Share Posted November 20, 2008 our "5th sound channel". Quote Link to comment Share on other sites More sharing options...
atariksi Posted November 20, 2008 Share Posted November 20, 2008 music from zx can be played on GTIA GTIA? The 1-bit DAC at 53279 bit 3 so need to simulate the waveform by timing things perfectly or you'll get some sort of buzzing sound as in: 10 POKE 54286,0 20 POKE 53279,0 30 POKE 53279,8 40 GOTO 20 Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 20, 2008 Share Posted November 20, 2008 Sounds like it's using PWM. I tried it using standard Pokey forced volume but wasn't in any way happy with the results. Could it be that the GTIA sound circuitry is more absolute in it's value as opposed to Pokey's kind of inbuilt attack/decay? It would be interesting to do a direct comparison - changing the program to instead use forced volumes of 0 and 8 on a Pokey voice and see if there's any difference. Quote Link to comment Share on other sites More sharing options...
atariksi Posted November 20, 2008 Share Posted November 20, 2008 Sounds like it's using PWM. I tried it using standard Pokey forced volume but wasn't in any way happy with the results. Could it be that the GTIA sound circuitry is more absolute in it's value as opposed to Pokey's kind of inbuilt attack/decay? It would be interesting to do a direct comparison - changing the program to instead use forced volumes of 0 and 8 on a Pokey voice and see if there's any difference. He can hook up the scope and see the waveforms using register 53279 vs. 53761 and see the difference. He can just write 16 and 24 instead of 0 and 8 to both registers since bit 4 is required to force audio output in volume mode whereas it has no effect on the GTIA register. I know that on the IBM PC, the speaker circuitry produced very good results of simulating a 8-bit DAC by toggling it on/off. Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 20, 2008 Share Posted November 20, 2008 /remembers Leaderboard on the IBM... "Look like he... hit the tree, Jim!" Quote Link to comment Share on other sites More sharing options...
xxl Posted November 20, 2008 Author Share Posted November 20, 2008 that is 2 channel solund. > It would be interesting to do a direct comparison - changing the program to instead use forced volumes of 0 and 8 on a Pokey voice and see if there's any difference. if you like you can use POKEY register. results is the same, but you can change volume for channels separately on 1 pokey channel. Quote Link to comment Share on other sites More sharing options...
Heaven/TQA Posted November 20, 2008 Share Posted November 20, 2008 holly sh!t... that sounds cool! Quote Link to comment Share on other sites More sharing options...
Chrodegang Posted November 20, 2008 Share Posted November 20, 2008 Impressive! Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 20, 2008 Share Posted November 20, 2008 I had a quick look at the program in the Monitor. Seems to use locations $80 and $90 for the amplitude values, as well as something else (?) Any chance of some source code, or to build a version which uses Pokey? Quote Link to comment Share on other sites More sharing options...
xxl Posted November 20, 2008 Author Share Posted November 20, 2008 on pokey it plays the same, belive me. soon i upload demo with gtia/pokey player zx music (on pokey with volume control) Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 20, 2008 Share Posted November 20, 2008 I'll have to look into this. I did a PWM player - fair enough it was rough & ready and the delays weren't very accurate. But it sounded totally crap so I didn't bother going further with it. The thing with PWM is that if you get it right, you can get more than the 6-bit precision that the Atari can (kind of) do. Quote Link to comment Share on other sites More sharing options...
emkay Posted November 20, 2008 Share Posted November 20, 2008 dont play it on emulator (emulator has bug), mp3 recorded on real atari. One ? Thousands Quote Link to comment Share on other sites More sharing options...
emkay Posted November 20, 2008 Share Posted November 20, 2008 (edited) Impressive! What? Interesting. Using full CPU power with display off producing sounds via the Keyclick generator is impressive? Impressive would mean to have those sounds with display on and ingame. Another interesting thing is that no one takes care about 2 channel 16 bit pokey music for that. Edited November 20, 2008 by emkay Quote Link to comment Share on other sites More sharing options...
emkay Posted November 20, 2008 Share Posted November 20, 2008 Probably, after unleshing all the possible of the A8, somone may find the forgotten register for turning colour mode in hires on Quote Link to comment Share on other sites More sharing options...
emkay Posted November 20, 2008 Share Posted November 20, 2008 I wonder if the cpu speed was fast enough when using the line counter. It could run than with double scanline modes at least. Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 20, 2008 Share Posted November 20, 2008 It might be possible to have a screen display without disrupting the sound much. A hires bitmap mode of 240 scanlines in widescreen mode would have a reasonably even spread of DMA Halts. Of course, the frequency would drop off and the notes would probably all have to be recalculated. Quote Link to comment Share on other sites More sharing options...
Tezz Posted November 20, 2008 Share Posted November 20, 2008 nice nice. I often wondered why GTIA sound has not been looked into or utilised so much. This is very good. xxl: soon i upload demo with gtia/pokey player zx music (on pokey with volume control) I can't wait to see (hear) that. are you possibly looking at the the 128+ and ST's 3 channel Yamaha YM2149 too? This is great stuff. Quote Link to comment Share on other sites More sharing options...
Tezz Posted November 20, 2008 Share Posted November 20, 2008 For those unaware of this ability of the A8, the heritage of this feature came from the architectures precursor to the CTIA/GTIA the 2600's TIA which combined the graphics and sound. The CTIA/GTIA continues this feature and so it's functions are not simply dedicated to graphics, for instance it is responsible for generating the keyclick. As is well documented the CTIA/GTIA used to control the speaker directly on the 400/800 but in the later XL/XE's, it is mixed with the audio output. Quote Link to comment Share on other sites More sharing options...
miker Posted November 20, 2008 Share Posted November 20, 2008 So... Now just wait for further improvements of GTIA sound abilities in emulators. No? Quote Link to comment Share on other sites More sharing options...
Tezz Posted November 20, 2008 Share Posted November 20, 2008 yea along with Pokey... we might have a long wait! let's hope emulation becomes acurate before our real hardware is extinct Quote Link to comment Share on other sites More sharing options...
UNIXcoffee928 Posted November 20, 2008 Share Posted November 20, 2008 (edited) hi, YERZMYEY/HOOY-PROGRAM from ZX-Spectrum scene send me some BEEP music. i rewrite 'music studio' player from zx spectrum and music from zx can be played on GTIA, dont play it on emulator (emulator has bug), mp3 recorded on real atari. http://www.ghnet.pl/~pin/atari_beep/part4.mp3 http://www.ghnet.com.pl/~pin/atari_beep/bee2a.mp3 http://www.ghnet.pl/~pin/atari_beep/beeporgy.mp3 I really like the downward pitch segment of your bass-line arpeggiation in bee2a.mp3. Nice contrast to the upward segment, much less predictable than what people usually do when arpeggiating on a keyboard. Usually one hears something like that with fast descending hammer-ons/pull-offs on a guitar. If you reduce the attack-time of the electro-toms, it will make the overall sequence sound even better. Sounds good, nice application of the GTIA. Edited November 20, 2008 by UNIXcoffee928 Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 20, 2008 Share Posted November 20, 2008 * Light bulb appears *ding* One possible way to do timing which will be interfered with to a lesser extent by screen DMA: Use 2 Players with the same XPOS. Position both players dynamically each time a delay is required (after WSYNC would be ideal). Then, store to HITCLR and wait for a collision event. A little more work than Pokey Timers, but Pokey Timers don't work properly in the emulator and are useless there anyway for sub-scanline increments. Quote Link to comment Share on other sites More sharing options...
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