pc9801-on.c

pc9801-on.c

/* pc9801-on.c
 * gcc -lasound -o pc9801-on{,.c}
 */

#include <alsa/asoundlib.h>
main()
{
        snd_pcm_t *h;
        snd_pcm_open(&h, "default", SND_PCM_STREAM_PLAYBACK, SND_PCM_ASYNC);
        snd_pcm_set_params(h, SND_PCM_FORMAT_FLOAT, SND_PCM_ACCESS_RW_INTERLEAVED, 1, 44100, 1, 10000);

        float w[2][0x4001], f = 0.2;
        int i = 0x2000;
        while (i--) {
                if (!(i % (11025 / 480)))
                        f = -f;
                w[0][i] = w[1][i*2] = w[1][i*2+1] = f;
        }

        snd_pcm_writei(h, w[0], 0x1500);
        snd_pcm_writei(h, w[1], 0x1500);
}