This is another article taken from the Unix newsnet. Transferred by Mike Blenkiron, and tidied by Dean Garraghty.¢----------------------------------¢¢¢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)¢¢¢Tom Klok.¢
