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Trying to make some PoKEY music!

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So I was able to try out that cool two-tone serial modulation when I was looking at Vinscool's test...

It's a little snippet of Jeroen Tel's Savage title theme at the part when ring modulation is being used
Note that I have *no* experience in assembly; I didn't write any sort of subroutine to change the SKCTL register depending on the instrument, but simply globally for the whole duration of the song. It was a quick hack of changing the byte which the tracker sets SKCTL before the song plays from #$03 to #$DE. Works in a pinch :)

 

savage2.xex

Edited by EnderDude
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Just for fun I ripped the .rmt out of your .xex and tested it in my own rmtplayer Two-Tone mode code, and sure enough, things work just as expected, it's triggered on the fly with the right setting and sounds almost exactly the same as your example :) 

Also, I have now implemented a proper region detection code, so it will run at the correct speed in either PAL or NTSC, or vice versa if a tune was intended for NTSC but runs in PAL, with the appropriate region displayed on screen.
 



Just for fun I also included my Fake SID test tune, running with the same code as well, the only different was the flag I have set before assembly so it runs at the correct speed in PAL too :D 

savage2.obx Fake SID.obx

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Aight, so this is another test where I'm using the two-tone mode with my 3 year old Sanxion bit I had. I'm still trying to figure out how to stay around the range of just regular pwm. I'm guessing it would have to be a bit more than twice the carrier frequency, but less than 3?

 

 

Sanxion2t.xex saxion2t.sap sanxion.rmt

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25 minutes ago, EnderDude said:

Aight, so this is another test where I'm using the two-tone mode with my 3 year old Sanxion bit I had. I'm still trying to figure out how to stay around the range of just regular pwm. I'm guessing it would have to be a bit more than twice the carrier frequency, but less than 3?

Ok first of all this is pretty awesome!
I really like that Ring Modulation effect using it there.

For making PWM using Two-tone, yeah, it's more or less what I have observed too.
More than twice the frequency and less than triple is the range that will work well for a stable PWM. 
My test tune Fake SID has that going for a few notes, that gave a really nice SID sound for sure!

Sweeping between this range of frequencies will modulate the pulse width with very precise control, unlike the normal Filter method.
I haven't yet learned much about this, so that's about all I can tell for sure.

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17 hours ago, EnderDude said:

Aight, so this is another test where I'm using the two-tone mode with my 3 year old Sanxion bit I had.

Thanks, best Atari version I've heard!

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On 8/4/2021 at 7:06 AM, EnderDude said:

Aight, so this is another test where I'm using the two-tone mode with my 3 year old Sanxion bit I had. I'm still trying to figure out how to stay around the range of just regular pwm. I'm guessing it would have to be a bit more than twice the carrier frequency, but less than 3?

 

 

Sanxion2t.xex 5.29 kB · 9 downloads saxion2t.sap 4.96 kB · 3 downloads sanxion.rmt 3.42 kB · 6 downloads

The 2 tone method won't really get my attention. Otherwise I'd use it more .

It sounds in some parts like the "missing link ", the 16 bit resolution makes it tuned better for sure. 

So some parts sound absolutely great by the correct pitch. But there are also parts in it that slap the face very hard. 

 

It's all about the missing tracker, and to put the features of POKEY to the point where the melodic part gets optimized. 

I've seen, a big progress this year, using the LZSS package. But it again ended up in some weird experimenting without getting  tunes seamless from the start to the end. 

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6 hours ago, emkay said:

The 2 tone method won't really get my attention. Otherwise I'd use it more .

It sounds in some parts like the "missing link ", the 16 bit resolution makes it tuned better for sure. 

So some parts sound absolutely great by the correct pitch. But there are also parts in it that slap the face very hard. 

 

It's all about the missing tracker, and to put the features of POKEY to the point where the melodic part gets optimized. 

I've seen, a big progress this year, using the LZSS package. But it again ended up in some weird experimenting without getting  tunes seamless from the start to the end. 

I must admit that I'd prefer to be able to hear what it sounds like in the tracker rather than going back and forth exporting the xex, changing the value in omnivore, then hearing it in Altirra, and fixing it through trial and error and repeating the process.

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There's a lot that I am now able to get directly in tracker using the RMT Patch 16 Beta3 code I did, and this became a lot closer to the LZSS output using custom tables as a result.
The disappointing observation out of this, however, is that the Two-Tone mode of the POKEY chip does *not* seem emulated in any of the RMT .dll plugins.
Otherwise, I already have the fully functional code to be able to use this mode in real-time, so the closest I can do for now is take a prepared module and assemble it into the custom player, and it will just work.

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13 hours ago, emkay said:

The 2 tone method won't really get my attention. Otherwise I'd use it more .

It sounds in some parts like the "missing link ", the 16 bit resolution makes it tuned better for sure. 

So some parts sound absolutely great by the correct pitch. But there are also parts in it that slap the face very hard. 

well I still like it... it doesn't sound like typical atari and it's catchy.

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It's really interesting that it seems not possible to put the simple features of such an old sound chip to an emulation.

Only 9 different registers and some physically dependencies ...

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4 hours ago, EnderDude said:

Even with apokeysnd.dll, which is probably one of, if not the most accurate pokey emulator .dll for RMT?

Yeah it does not seem to work either, this is the one I use.

 

I think the reason why this isn't emulated is simply because under normal usage, the Two-Tone mode isn't needed for sound generation.

 

It could certainly allow many cool effects when used, however.

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Indeed. So, I've also been trying to see if distortions other than pure square would work, and they do, but so far I only get what sounds like noise. I will experiment further with that though. For now, I've made another update to the Sanxion cover where the pwm is stable:

 

Sanxion2t.xex

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@EnderDude you may be interested to take a look to this thread: 

There are many things that have been getting thoroughly documented, a lot of which I have not yet experimented myself, so you may find a lot of interesting information.
@Synthpopalooza is very familiar with the Two-Tone mode so he is definitely the person who knows a lot of the secrets using these unusual combinations.

By the way, awesome cover! That Two-Tone filter sounds really awesome there!

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So far in two-tone, I've only gotten as far as $Ax distortions (64, 15, 64+1.79, 15+1.79) and parts of $4x distortion (the only useful clocks are 15+1.79 and 64+1.79).  There are other settings possible, the $2x with 1.79, $8x with 1.79 plus 9-bit poly, and the $Cx distortions (all four combinations) show some promise.  $Ax is pretty much 98% documented and I have note tables.  $4x ... very incomplete, with a long way to go.  It is complex, with multiple settings and note tables.

 

Short version:  $4x has multiple settings, from crunchy, biting guitars, alien heartbeat sounds, to the standard $Cx distortion ran through a fuzzbox effect.  One setting also allows you to play 4 distortion in one channel, while the second one takes $Cx.

 

In the $Ax settings, ou can also play $Ax in the second channel instead of silencing it, this adds a nice saw harmonic to the sound.

Edited by Synthpopalooza
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6 hours ago, EnderDude said:

Indeed. So, I've also been trying to see if distortions other than pure square would work, and they do, but so far I only get what sounds like noise. I will experiment further with that though. For now, I've made another update to the Sanxion cover where the pwm is stable:

 

Sanxion2t.xex 5.56 kB · 1 download

This is much better. In some places "authentic". 

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7 hours ago, EnderDude said:

Indeed. So, I've also been trying to see if distortions other than pure square would work, and they do, but so far I only get what sounds like noise. I will experiment further with that though. For now, I've made another update to the Sanxion cover where the pwm is stable:

 

Sanxion2t.xex 5.56 kB · 2 downloads

You rock! :D

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Yes, it happens sometimes. It happened to me with this one:

 

 

Good luck monetizing 36 views ;)

 

But I wish Iron Maiden all the best, and they deserve this, ehm... cent :)

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while I love the band and their music, it's often ripped from other writings and influences... sometimes blatant and other times not so much. Being so quick to protect their own stuff containing those other works etc. A number or their stories and songs are retelling of biblical stories and story lines as well as the flip sides of the same. Some of the stuff is just re mixes of old rhymes and poems etc. I would prefer that they let others do as they did, then they'd be hardcore in what they've said and done, commanding respect.

 

Oh well, Welcome to the Hell that is copyright corporate clutching lawyer loving lowdown laydowns of the law 😮

 

heh, I did that...

 

Now place the needle on the vinyl and listen to the rhyme of the ancient mariner... awesome stuff! I highly recommend it when your in that particular sort of mood!

Edited by _The Doctor__
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