From: Ullrich von Bassewitz (uz_at_musoftware.de)
Date: 1999-12-01 09:22:11
> Okey, but i heard I had to make a irq player or something to make the > sid file run/play. tell me more please :) You don't need an IRQ player to play the SIDs. The only thing of importance is that the play routine is called in regular intervalls. If your program manages to call the routine without using an IRQ that's ok. Usually, things are simpler if you use an IRQ handler, since you don't have to care about it, it works in the background. But since a SID player has nothing to do apart from playing the music, you may also do without. I'm pretty sure that SIDPLAY under Linux does not use any interrupt... Writing an IRQ handler is not too difficult, but it should be written in assembler. You may call C functions from the assembler code, but this needs special precautions for reentrancy and is usually not worth the effort. If you need sample code for a program that combines an IRQ handler written in ASM with more code written in C, you may have a look at my morse trainer. The source is available from ftp://home/ftp/pub/uz/misc/morse-64-1.0.zip The actual tunes (three voices) are played by an IRQ handler in the background, all other stuff (user interaction, precalculation, effects...) is done in C. Regards Uz -- Ullrich von Bassewitz uz_at_musoftware.de ---------------------------------------------------------------------- To unsubscribe from the list send mail to majordomo_at_musoftware.de with the string "unsubscribe cc65" in the body(!) of the mail.
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