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#126 analmux OFFLINE  

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Posted Wed Jul 6, 2005 10:33 AM

(hm this one with a cool baseline and some percussions  :ponder: )


well, where are the baseline+percussions then ??? :ponder: I didn't hear any in the testsong.

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You mean this?

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:cool: yes, that's what I mean..

Cool tune. Do you have plans with this (i.e. to finetune melodies for instance), then I can give you some (more harmonic) suggestions on the arpeggios in the first part.

#127 emkay OFFLINE  

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Posted Wed Jul 6, 2005 10:41 AM

(hm this one with a cool baseline and some percussions  :ponder: )


well, where are the baseline+percussions then ??? :ponder: I didn't hear any in the testsong.

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You mean this?

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:cool: yes, that's what I mean..

Cool tune. Do you have plans with this (i.e. to finetune melodies for instance), then I can give you some (more harmonic) suggestions on the arpeggios in the first part.

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Ähm.... for me it's perfect (you will recognize heavy miss-tones in the editor) .... mpls.... you have mail ;)
.... though pokeys is mearly singing this tune :D

Edited by emkay, Wed Jul 6, 2005 10:46 AM.


#128 emkay OFFLINE  

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Posted Wed Jul 6, 2005 3:56 PM

Do you have plans with this (i.e. to finetune melodies for instance), then I can give you some (more harmonic) suggestions on the arpeggios in the first part.

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reacting to your suggestion, here another waste of an evening ;) for some changes on the main voice.
I added a second instrument... a third one will be necessary, I think.

#129 analmux OFFLINE  

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Posted Wed Jul 6, 2005 5:31 PM

Okay, for everyone that has a (only) a (buggy) emulator. Here's some real pokey music: mp3's recorded from a real (single) pokey from my home PAL atari 800 xl. These tunes were posted in this thread earlier.

BE AWARE: THIS IS WHAT POKEY IS ABLE TO DO!!!!







#130 Heaven/TQA OFFLINE  

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Posted Fri Jul 8, 2005 1:45 PM

emkay...i have a new tool for you... have a look here...

http://www.cncd.fi/aeeben/

there is a vic-20 soundmon... :D maybe you can push this very old chip as well...

#131 emkay OFFLINE  

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Posted Fri Jul 8, 2005 5:14 PM

emkay...i have a new tool for you... have a look here...

http://www.cncd.fi/aeeben/

there is a vic-20 soundmon... :D maybe you can push this very old chip as well...

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Perhaps, when POKEY's hi level programming is optimized to the real limits ;)

I'm not really "pushing POKEY" , it's just usage of what pokey can do by "simple" programming with the features of RMT, though pokey ever had the abilities of using 15kHz-filter ...

Try to "combinate" one 15kHz filter-voice (as in the turrican tune) with the 1.79MHz filter-voice (Violin of Doom) plus two softsynth channels.... at the same time.
:ponder:

#132 analmux OFFLINE  

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Posted Sat Jul 9, 2005 5:15 AM

....Try to "combinate" one 15kHz filter-voice (as in the turrican tune) with the 1.79MHz filter-voice (Violin of Doom) plus two softsynth channels.... at the same time.
  :ponder:


I don't know....for softsynth you usually need a pokey timer interrupt for which one channel's frequency pulse is triggering IRQ on the cpu. 15kHz filter + 1.79MHz filter already use 4 channels, plus, you can only use channels 1,2 or 4 for IRQ triggering...so when you use 2 hardsynth voices (ch. 1,2) for the main pitches, then you'd only have channel 4 left, but this is also used for channel 2 filter pitch.

Another possibility would be off course a software timer: i.e. like a variable waiting loop (for 2 softsynth voices you'd need 2 simultanteous waiting loops), which updates volume-only-channels. This loop's length depends on the played notes (like a wavelength value)....though I wonder whether it's possible to have the first two channels generating hardsynth sounds and for the other two, while their frequency registers are used for filtering the first two channels, at the same time their volume registers are used for playing back samples.

....so I think I have an idea how to do that, but will we ever see (hear :D ) this kind of thing on the Atari, when there are nowadays only two fools on the atariage forum that spend some of their (free) time to experiment with RMT. :ponder:

Edited by analmux, Sat Jul 9, 2005 5:17 AM.


#133 emkay OFFLINE  

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Posted Sun Jul 10, 2005 3:03 AM

Another possibility would be off course a software timer: i.e. like a variable waiting loop (for 2 softsynth voices you'd need 2 simultanteous waiting loops), which updates volume-only-channels. This loop's length depends on the played notes (like a wavelength value)....though I wonder whether it's possible to have the first two channels generating hardsynth sounds and for the other two, while their frequency registers are used for filtering the first two channels, at the same time their volume registers are used for playing back samples.


Software-controlled would be ok, because only "low" tones would be needed to create by "digitizing". POKEY itself gives enough possibilites to create & manipulate high tones.

....so I think I have an idea how to do that, but will we ever see (hear  :D ) this kind of thing on the Atari, when there are nowadays only two fools on the atariage forum that spend some of their (free) time to experiment with RMT.  :ponder:

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Compared to ~ 6 Billion people on earth, "two" really seems rather low ;)

#134 Xebec's Demise OFFLINE  

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Posted Sun Jul 10, 2005 11:48 AM

BE AWARE: THIS IS WHAT POKEY IS ABLE TO DO!!!!

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On an actual Atari, would you have enough processing power to run those in the background of a game?

#135 emkay OFFLINE  

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Posted Sun Jul 10, 2005 11:56 AM

BE AWARE: THIS IS WHAT POKEY IS ABLE TO DO!!!!

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On an actual Atari, would you have enough processing power to run those in the background of a game?

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Ofcourse! It's 50Hz VBI programming.

#136 analmux OFFLINE  

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Posted Sun Jul 10, 2005 3:23 PM

On an actual Atari, would you have enough processing power to run those in the background of a game?

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Yes, as emkay said, 50Hz programming means that the player that actually plays the music does work inside a Vertical Blank interrupt. Maybe you've once seen a .xex working of one of the RMT songs. Then, when you see a light bar in the middle of the screen, that's an indicator of how much CPU cycles the player takes.

You can see that an average RMT executable takes about 16-22 rasterlines (114 cycles per rastrerline)....this is about 7% of the total CPU time. This is quite usual for ingame music.....though when you do optimizations maybe you'll end up with just 4 or 5 % of cputime

#137 analmux OFFLINE  

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Posted Sun Jul 10, 2005 5:12 PM

Now, hear this testrecording: it's a pokey playing triangle waves with 2 combined voices, that's all I have to say. maybe someone can guess how I did it :)



...note: the fact that I didn't just post a .xex of this can be explained by this: when I do this in the emulator it just remains plain silent

Edited by analmux, Sun Jul 10, 2005 5:13 PM.


#138 emkay OFFLINE  

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Posted Sun Jul 10, 2005 5:27 PM

Now, hear this testrecording: it's a pokey playing triangle waves with 2 combined voices, that's all I have to say. maybe someone can guess how I did it  :)



...note: the fact that I didn't just post a .xex of this can be explained by this: when I do this in the emulator it just remains plain silent

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If the emulation could bring us this sounds, too , we would have a full "new" POKEY sound-world available. Which means soft- and almost noiseless music.

#139 emkay OFFLINE  

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Posted Mon Jul 11, 2005 4:55 AM

Ladies & gentlemen,

you're supposed to hear an amiga MOD file with digitized samples from a Midi-system and a C64 and the cpu usage is about 100% to have this sounding accuracy....



NOT!

:ponder: :D

#140 analmux OFFLINE  

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Posted Mon Jul 11, 2005 7:37 AM

Ladies & gentlemen,

you're supposed to hear an amiga MOD file with digitized samples from a Midi-system and a C64 and the cpu usage is about 100% to have this sounding accuracy....



NOT!

:ponder:  :D

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Okay, here's an update of the recording:


...and here's my experiment with triangle waveforms inplemented in the 'violin of doom' song:

You may notice that (unfortunately) the triangle waveforms give a slightly destructive effect (interference?) on the other channels.

#141 Heaven/TQA OFFLINE  

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Posted Mon Jul 11, 2005 8:14 AM

the turrican testtune is amazing.... imho...

#142 emkay OFFLINE  

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Posted Mon Jul 11, 2005 8:32 AM

...and here's my experiment with triangle waveforms inplemented in the 'violin of doom' song:

You may notice that (unfortunately) the triangle waveforms give a slightly destructive effect (interference?) on the other channels.

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OK. Volume correction is the plot here.
But, something must be wrong here. I remember experimenting with this sounds (lightyears ago ;) ), having a way louder tone.
Have you experimented with volume changes?
Perhaps giving a try to build an arpeggio with filtered/unfiltered sounds?

#143 emkay OFFLINE  

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Posted Mon Jul 11, 2005 8:39 AM

the turrican testtune is amazing.... imho...

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Heaven,
it's simply what pokey is capable of....
And, as Analmux's find shows, there is a lot more potential...

Edited by emkay, Mon Jul 11, 2005 8:39 AM.


#144 analmux OFFLINE  

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Posted Mon Jul 11, 2005 8:57 AM

OK. Volume correction is the plot here.
But, something must be wrong here. I remember experimenting with this sounds (lightyears ago ;) ), having a way louder tone.
Have you experimented with volume changes?
Perhaps giving a try to build an arpeggio with filtered/unfiltered sounds?

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...but didn't you need more than 2 voices for your 'flute' sound? maybe I can try similar things...though the triangle waves in the 'violin' song are at max. volume, so another solution is making sounds on the other channels more silent.

maybe this is the reason why there's destructive interference: your drum&bass instruments are at vol.15, and both combined triangle wave channels are at vol.15: I remember there was a rule that in order to kill heavy distortions you should keep total volume (=added volumes of all 4 channels) under 32 :ponder:

#145 emkay OFFLINE  

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Posted Mon Jul 11, 2005 9:04 AM

...though the triangle waves in the 'violin' song are at max. volume, so another solution is making sounds on the other channels more silent.



that's the way :)

#146 analmux OFFLINE  

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Posted Tue Jul 12, 2005 11:24 AM

In the meantime, read this interesting article in compute's 2nd book of atari

http://www.atariarch...2ba/page213.php

how the pitch-value depends on the needed frequency is very important for computing side-effect frequencies, such as used in 1.79 mhz filtered sounds and triangle wave generation

#147 analmux OFFLINE  

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Posted Tue Jul 12, 2005 2:31 PM

OK the triangle wave trick is as follows:

we use channel 1 and 3 at 1.79mhz, but without filtering.
now poking relatively high values to audf1 and audf3 results in inaudible high notes (above 20 khz), but when they differ slightly, they interfere, giving a sub-harmonic tone

the frequency FR of the resulting tone is:
FR = (F1 - F3) /2

knowing that (with known pitch P1 and P3 values) F1 and F3 are given by this:
F1 = Phi/(2*(P1+4)) ; F3 = Phi/(2*(P3+4)) where Phi is the main computer clock (PAL: Phi = 1773447, NTSC: Phi = 1789790)

Now, if we set a pitch P1 = P and P3 = P+1 we get minimal unwanted overtones

Turning on the real hardware you may do this:
* first make sure all voices are enabled:
sound 0,100,10,10 : end

then
Pokey=53760: poke Pokey+8,96: poke Pokey+1,175:poke Pokey+5,175

Here: distortion A and volume F is used on both channels 1 and 3, and 1.79mhz clocking is turned on

then
poke Pokey,27: poke Pokey+4,28
Then, on PAL machines, you might hear a 440Hz note (A)

.....
Now, how to compute the pitch values from the needed frequency:

If P3 = P1 + 1, then:
FR = Phi/(2*(P1+4)*(P1+5))

inverting this relation to get P1 from FR we apply the abc-formula:
P1 = -4.5 + 0.5*SQR(1+Phi/FR)

voila:
so now:
poke Pokey,P1: poke Pokey+4,P1+1
gives the wanted frequency.

Similar formulas can be constructed for filtered instruments e.a.

Edited by analmux, Tue Jul 12, 2005 2:31 PM.


#148 Heaven/TQA OFFLINE  

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Posted Tue Jul 12, 2005 3:00 PM

ehmmm....that's exactly why i haven't studied physics and math... ;)

#149 emkay OFFLINE  

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Posted Wed Jul 13, 2005 4:15 AM

ehmmm....that's exactly why i haven't studied physics and math... ;)

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This isn't really difficult to understand :)

With the pokey we have two possibilities to play correct notes.

One is to use 16Bit
One is to use filter with different frequencies (including the possibility of creating triangles with two channels).

Actually, both are not supported by RMT.

The 16bit functionality is "blocked" and the 100% filter usage isn't given due to the still buggy emulation. Even the high quality emulation in the A800win plus 4 has it's flaws.
So what's easier?
Creating an RMT that is running on a real machine, or to create a pokey emulation with 100% sounding accuracy?


Listening, what we got already:

almost clean sawtooth waves: Violin
almost clean triangle waves: Flute
Guitar, Trombone etc...pp
And "controll-able random" waves for a huge variation of "soundings" even usable for music.

But, only if we have "one" complete piece (full POKEY supporting Tracker with all the good features of RMT & a full working POKEY environment" for creating pokey music... Some guys really will be astonished.

#150 Asolac OFFLINE  

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Posted Sat Jul 16, 2005 11:56 AM

Would it be possible to use this to create something akin to Paul Slocum's Synthcart for the C64? A small, stand-alone program for using the keyboard and the Pokey as a synthesizer, and avoiding the need to load up a more complex music program?




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