Msg: 68 *Conference*
06-09-91 13:17:17
From: FRANK MCJUNKINS
To : CHARLES STEVENS
Subj: 102 TONES
Thanks for the 'basic' info, Charles. I didn't get the end of you message though. In the meanwhile, I'm getting a little soured by the lack of response to inquiries about this machine. In a way its good, as its forced me to spend a whole lot more time than I anticipated learning the machine and its in's and outs. I discovered the answer to my own question which is answered here for anyone else who wants to make the 102 create a specific tone frequency OTHER than the musical notes: Fa = Desired audio tone. Fs=SOUND number. 4915200 (Clock xtal freq.) Formula is: 4915200/Fa=N N/2=Fs Example. You want to make the machine create a 1000 cycle (hertz) tone. 4915200/1000=4915.2 4915.2/2=2457.6 SOUND=2457.6 The stability will depend on the actual crystal frequency and the ambient temperature of the machine. I found the tone that results when I use this formula is within a few cycles of what I really want, so if your use is critical, you may need to play with the numbers a bit to compensate for the crystal being off frequency, and also remember that the temperature of the computer will affect the crystal frequency and thus the resulting SOUND number. Now the next project is to discover where I can get the actual audio frequency output from the machine, and find a way to make a sine wave out of the apparent square wave audio tone that the SOUND number creates.