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3 minutes ago, ParanoidLittleMan said:

I did not mean that Atari's 50066 Hz was bad for sound quality or like - just that was not compatible.

I agree that this frequency is very unusual, I don't know of any other system which uses it.

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3 minutes ago, ParanoidLittleMan said:

I did not mean that Atari's 50066 Hz was bad for sound quality or like - just that was not compatible.

I remember that I tested the DMA sound on different machines and that the actuel frequencies were not exactly the same on a TT and on a STE.

I made tests (a large sound that I played with DMA measuring the time).

It appeared that on a TT (compared to a STE):

    remplace 12517 with 12584,
    remplace 25033 with 25169,
    remplace 50066 with 50337.

Then, I went on investigating...

The DMA sound seems to be driven by a clock derived from the CPU clock.

On the TT, the crystal is at 32 215 906 Hz (the double of the VME clock that is documented to be 16.107953 MHz).

and:

 

32 215 906 / 2560 = 12584

32 215 906 / 1280 = 25169

32 215 906 / 640  = 50337

 

That looks correct to me.

 

So, the DMA on the STE must derive from the CPU clock, something like:

8 010 880 / 640 = 12517

A CPU clock at 8,01088 MHz.

 

Guillaume.

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4 hours ago, vol said:

Thank you very much.  Your Atari is the fastest in my tables that have just been updated.  It is interesting that the 68020 and 68030 show almost identical performance.

 

Just wait until someone with a 50mhz Pak 68/3 board with FAST RAM, or a

TT030 with a working Cattamaran @48mzh and FAST RAM runs this, won't

be in front long...  :)

 

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Yes, I expected that someone will see that those 50066, 25033 freqs are just divided from main, roughly 32 MHz clock, or rather from roughly 8 MHz for CPU. That way Atari saved on one crystal.

I had no clue about exact clock in TTs, and will avoid to listen music, played so rushed on it 🙂

 

And to add that freqs are for sure not exactly same in NTSC  (America) and PAL (Europe) STEs (as it is with STFMs too) . There is slight diff. , and the reason is avoiding interference with color carrier in NTSC or PAL encoder.  I googled little, but instead exact crystal freqs found another sad example how some 'experts' are poor with knowledge: https://comp.sys.atari.st.narkive.com/vUJrGBhT/atari-st-crystal-frequencies

 

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21 hours ago, vol said:

...

Thank you very much.  Your Atari is the fastest in my tables that have just been updated.  It is interesting that the 68020 and 68030 show almost identical performance.

As I know 68030 is 68020 with added PMMU unit. And maybe with more flexible data lines - can be set for 32, 16 and ? 8 bit wide bus. 

What hurts is that was launched later than 80386 - so blame not only Atari, but Motorola too for losing market .

And about prices:  PCs with 32 bit 80386 were too expensive, even around 1993, 80386SX was what was sold then more .

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19 minutes ago, ParanoidLittleMan said:

Yes, I expected that someone will see that those 50066, 25033 freqs are just divided from main, roughly 32 MHz clock, or rather from roughly 8 MHz for CPU. That way Atari saved on one crystal.

I had no clue about exact clock in TTs, and will avoid to listen music, played so rushed on it 🙂

 

And to add that freqs are for sure not exactly same in NTSC  (America) and PAL (Europe) STEs (as it is with STFMs too) . There is slight diff. , and the reason is avoiding interference with color carrier in NTSC or PAL encoder.  I googled little, but instead exact crystal freqs found another sad example how some 'experts' are poor with knowledge: https://comp.sys.atari.st.narkive.com/vUJrGBhT/atari-st-crystal-frequencies

 

If you want to test the actual DMA soudnfrequencies on one particular machine, you can use my little tool !

 

Guillaume.

dmasound.zip

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On 5/4/2021 at 7:56 PM, DarkLord said:

 

Just wait until someone with a 50mhz Pak 68/3 board with FAST RAM, or a

TT030 with a working Cattamaran @48mzh and FAST RAM runs this, won't

be in front long...  :)

 

I happen to have that exact TT setup. Next time I am in Maine I’ll give it a try.

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2 minutes ago, mdivancic said:

I happen to have that exact TT setup. Next time I am in Maine I’ll give it a try.

 

Looking forward to the results - it should edge my Pak 68/3 equipped STacy by a wee bit.  :)

 

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Hurra ! Instead Amiga vs ST war we have now TT vs Paked Stacy war 🙂   Sorry, could not resist 🤩

Serious mode on: That PAK 68/3 in Stacy - is it using regular ST video/graphic HW or there is some added graphic module, card - like Nova  ?

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6 hours ago, ParanoidLittleMan said:

Hurra ! Instead Amiga vs ST war we have now TT vs Paked Stacy war 🙂   Sorry, could not resist 🤩

Serious mode on: That PAK 68/3 in Stacy - is it using regular ST video/graphic HW or there is some added graphic module, card - like Nova  ?

 

Funny.  :)

 

Nothing special about the video hardware. It's the stock monochrome LCD screen that comes with a STacy.

 

640 x 400 resolution.

 

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Posted (edited)
10 hours ago, ParanoidLittleMan said:

Hurra ! Instead Amiga vs ST war we have now TT vs Paked Stacy war 🙂   Sorry, could not resist 🤩

Serious mode on: That PAK 68/3 in Stacy - is it using regular ST video/graphic HW or there is some added graphic module, card - like Nova  ?

The Atari ST is just a bit faster than the Amiga but the Amiga has its advantages too. ;)  It is interesting that this resembles the situation with the Atari 800 and Commodore 64.  History repeated itself. :) It is also interesting that the Apple II and first Macs were slower than the Commodore 64 and Amiga and had less impressive graphics/sound than the Atari 800 and Atari ST but Apple beat Commodore and Atari.

Edited by vol

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An Amiga guy has been able to do an almost impossible thing and find a way to make the algorithm implementation faster a little.  He also helped to prove that the 68020/30 code is actually faster than the 68000 code now.  So please help me again.  Run pi-st and pi-st30 on your hardware for me (100/1000/3000 digits).  I am sure that further improvements are impossible so this is rather my last request. 

pi-st-6.zip

Edited by vol

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