Author Topic: cpc 464 inconsistant sound issue  (Read 1113 times)

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Offline falken

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cpc 464 inconsistant sound issue
« on: 17:19, 08 March 15 »
Hello  :)

I'm trying to debug a sound problem with my cpc, when I run a game the music sounds quite crazy, notes wrong and stuff like that.

I've done some testing with the basic "sound" command, in comparison with winape. I made a little program as follows:

10 x=1
20 sound x,400,50,15

The documentation  says: SOUND <channel status>, <tone period>[,<duration>[,<volume>]]
So my understanding is that this should play a tone on channel x, with frequency 400, duration 40 and volume 15.

I ran this multiple times in winape, with x at values 1,2 and 3. Each time the same single tone was produced.

I ran this multiple times on my cpc, again with x at values 1,2 and 3. This time different tones were produced, sometimes high, sometimes low. Sometimes two different tones at once.

Does this point to a particular issue with the mobo? Could the resistors be faulty?

Thanks for any advice :-)
« Last Edit: 17:32, 08 March 15 by falken »

Offline McKlain

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Re: cpc 464 inconsistant sound issue
« Reply #1 on: 23:13, 08 March 15 »
About the channel values you need to use 1,2 and 4 (left, center, right).

Code: [Select]
The <channel status> parameter must yield an integer in the range 1 to 255. The
parameter is bit significant, with each bit of the binary value of <channel status>
signifying the following:
Bit 0: (decimal 1) send sound to channel A (Least significant bit)
Bit 1: (decimal 2) send sound to channel B
Bit 2: (decimal 4) send sound to channel C

But still, there must be something wrong with your cpc.