[net.micro.cbm] SID NOISE

rcf@inuxd.UUCP (R Fitch) (11/28/84)

	I am having trouble with the excessive background
	noise on the audio output line of my C64.  I make
	morse code tapes for Amateur radio classes with a
	program I have written but when I try to record,
	the background noise from the cpu etc. is really
	annoying.  I finally gave up and now key an external
	oscillator which is really dissapointing since I
	cannot use the SID for which it is intended.

	Has anyone found the right bypassing or modification
	to the SID to solve this problem or am I the only
	one experiencing the problem??? I have tried 3 other
	C64's and all are the same.

			Help will be greatly appreciated!

				R. C. Fitch /AT&T CP Indy

russell@ihuxu.UUCP (Larry Russell) (12/02/84)

I set the volume parameter to 0 during periods of silence.
This is a kluge, but it works.
I've noticed that most canned software (games,etc.) doesn't have this problem,
so I assume they do something similar.
Incidentally, I tried to use the SID filter to filter out the noise,
but this had no effect, so the noise must enter past that point in the
device.
-- 

				Larry Russell
				AT&T-Bell Laboratories
				Naperville, IL
				ihnp4!ihuxu!russell