On Tuesday 24 January 2006 22:45, Fabrice Bellard wrote: > If you want to model the real PC speaker, the best to do is to generate > a square signal and to pass it thru a low pass filter with a cut off > frequency of a few kHz. Then you could even be able to play samples thru > the simulated PC speaker using the tricks used in old MSDOS programs, > provided QEMU implements a precise cycle counter (it will come someday > !).
Change that few to 15 [kHz] and that would be what some PC-speaker hooking SB-clones did. But there were PCs with piezoelectric speakers, and those could genereate sounds well above 20kHz. But yes, typically 12-15kHz cutoff with 1st or 2nd order filter would do the trick. And if someone wants full reality one would also need some not-too-strong (1st order, 6dB/oct) hi-pass filter around 80-120Hz -- as those tiny PC-speakers are unable to emit bass. rgds -- Sebastian Kaliszewski _______________________________________________ Qemu-devel mailing list Qemu-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/qemu-devel
