[comp.sys.atari.8bit] 16-bit Sound

Tom_Klok@mindlink.UUCP (Tom Klok) (02/10/91)

> umhild11@ccu.umanitoba.ca writes:
> 
> My request is this:would some kind soul find this article and copy out the
> table for me, or failing that, does anyone know the equations which will give
> me the correct values for these tables?

From the Hardware Manual:

The POKEY counters can be clocked at three different frequencies:
1.78979 MHz
63.9210 KHz
15.6999 KHz

The Normal Formula for output frequency is:

        Fout = Fin / 2N

where N = the binary number in the frequency register (AUDF), plus 1 (N = AUDF
+ 1).  The Modified Formula should be used when Fin = 1.79 MHz and a more exact
result is desired:

            Fin
Fout = -------------
       2 (AUDF + M)

where M = 4 if 8 bit counter (AUDCTL bit 3 or 4 = 0)
      M = 7 if 16 bit counter (AUDCTL bit 3 or 4 = 1)

--

So, in your case, you'd want to use the formula

        1.78979 x 10^6
Fout =  --------------   Hz
         2 (AUDF + 7)

Hope that helps.

Tom Klok
a344@mindlink.UUCP   |   "What, me hurry?"   -- Alfred E. Von Neuman

deg@sei.cmu.edu (Donald Griffin) (02/23/91)

You were looking for the 16-bit sound table from a COMPUTE! magazine.  While
I don't want the responsibility for typing it in (with errors!), I do have the
article in question  (page 214 in the March, 1983 issue), and will be happy to
mail you a copy if you wish to provide an address.

Let me know if I can be of help.

Don Griffin