Lynxpro Posted August 23, 2014 Share Posted August 23, 2014 If any pokey experts have an fpga board I'd be very interested in finding features I need to fix/improve on. What about the Rapidus board? Supposedly, it does Quad POKEY and Dual SID emulation…and possibly at the same time... Quote Link to comment Share on other sites More sharing options...
foft Posted August 23, 2014 Share Posted August 23, 2014 (edited) Getting closer... http://www.scrameta.net/autobuild/instrumentarium/Instrumentariumv2.mp3 I re-did the plls - timing should be much closer (2% vs 0.1% wrong - I can't get exact for PAL). I fixed 2-tone I think (bit 7 forces serial out to 0 - I was doing this after the 2-tone logic). Poly counters now pass Perry's linked test. Still not sure about the poly 5 issue though - does the problem still exist? Edited August 23, 2014 by foft 3 Quote Link to comment Share on other sites More sharing options...
thorfdbg Posted August 24, 2014 Share Posted August 24, 2014 One example: ...You can find more here. I hope it's now clear enough. http://atariage.com/forums/topic/149261-a-new-pokey-tune-unusual-instruments/?p=1820884 Thank you a lot! I fixed this - actually, this was caused by the pokey "channel mute" logic being a bit overly ambitious as it disabled the high-counter of a high-low channel pair even though the high-counter is required to drive the reset-logic of the low counter. Thus, next release will get this right! 2 Quote Link to comment Share on other sites More sharing options...
foft Posted August 24, 2014 Share Posted August 24, 2014 Still not sure about the poly 5 issue though - does the problem still exist? So from the times with problems I guess the issue I have is with: ---------------------------------------------------- Distortion 2 at 1.79 MHz: (0:46 - 1:09, 1:32 - 1:39) Channel: 1 or 3 Pokey Distortion: 2 AUDCTL settings: x1x0x0xx or xx1x00xx Custom Notation Table 1 Remarks: -This instrument gives better-tuned high notes, independent of 15 kHz or 64 kHz mode (see http://atariage.com/forums/topic/149261-a-new-pokey-tune-unusual-instruments/?p=1820884). I tried to reproduce this in basic, but I get what appears to be a near identical sound. 10 P=53760 20 TL=250 30 POKE P+8,64 40 POKE P+1,74 50 POKE P,TL 60 GOTO 60 i.e. 1.79MHz channel1, distortion 2 (010 - 4 bit and 5 bit together) Is this the sound the problem is heard with? Quote Link to comment Share on other sites More sharing options...
analmux Posted August 24, 2014 Author Share Posted August 24, 2014 @ foft No, distortion 2 only plays the poly5, not combined with poly4, 9 or 17. Do you use a real atari by the way? Quote Link to comment Share on other sites More sharing options...
analmux Posted August 24, 2014 Author Share Posted August 24, 2014 Ah, I see in line 40: POKE P+1,74 is equivalent to distortion 4: use hi nybble: 74 = 16*4 + 10, thus distortion 4, volume 10. Yes, this is poly4+poly5. POKE P,TL, with TL=250 gives the real pitch: 250+4 = 254 = 2*127, which isn't divisible by 3,5 and 31: it's a maximal sound combination w.r.t. poly4 and poly5. Quote Link to comment Share on other sites More sharing options...
foft Posted August 24, 2014 Share Posted August 24, 2014 (edited) Thanks - I see. So 0010, not 0100... I'll make that change and try tomorrow.I thought you meant 2 in the 3 bits as described here:Yes I have a real 600XL and XEGS here to compare with. Edited August 24, 2014 by foft 1 Quote Link to comment Share on other sites More sharing options...
foft Posted August 25, 2014 Share Posted August 25, 2014 (edited) Reproduced. Removed inversion on the poly 5 output (its on the decap schematic, which also has the wrong terms to the xnor) and it matches now with my test. Thanks for the help, this should be pretty close now. Sure enough instrument starting just after 45seconds ish match frequency better:-) Instrumentariumv3.mp3 Edited August 25, 2014 by foft 2 Quote Link to comment Share on other sites More sharing options...
foft Posted August 25, 2014 Share Posted August 25, 2014 Another interesting case:10 P=5376020 POKE P+8,6430 POKE P+1,10+3231 POKE 53775,1140 POKE P,2050 GOTO 50 Relatively low frequency on my 600XL, higher frequency on my implementation and on Altirra 2.5 (not checked latest test). Perhaps down to two tone delays? I haven't adjusted delays with 2-tone mode. Two-tone extra delay description. Have to connect up the scope/LA I guess... 1 Quote Link to comment Share on other sites More sharing options...
phaeron Posted August 26, 2014 Share Posted August 26, 2014 I've known about some inaccuracies in Altirra's emulation with two-tone mode at 1.79MHz rates but haven't gotten around to tracking them down. Last time I ran into it was when I was working with PWM audio, where some max amplitudes worked in emulation but crackled on the real hardware. If I simplify the case to a lower pitch square wave and hold down timer 2 so it doesn't interfere, it sounds like the timer 1 period needs to be lengthened by two cycles. However, that's not enough to fix the case above, where there is some other interaction going on. 1 Quote Link to comment Share on other sites More sharing options...
emkay Posted August 30, 2014 Share Posted August 30, 2014 (edited) Anti forget propaganda The Video shows some different tunes played in Altirra. Seems the 60Hz plays "speed stable". Not sure about the timing. Some tunes use "instruments" with special timings and some also use "Filter-Modulations" . Minimod has only some adjustments and the main filter runs free (for example) All of them were played at 50Hz speed. Not sure about the channel mixing. To me it seem "over" compared to the real thing. It's all the same volume and the same Altirra-settings. Just different usage of the soundgenerators. Edited August 30, 2014 by emkay 2 Quote Link to comment Share on other sites More sharing options...
analmux Posted September 17, 2014 Author Share Posted September 17, 2014 ... Which mathematics are going to help me out here? F.e. this link I hope: atariage.com/forums/topic/124994-pokey-help/?p=1524134 It's an example of sawtooth mathematics, i.e. square roots, quadratic equations, prime numbers, relatively prime pairs. Quote Link to comment Share on other sites More sharing options...
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