EMU_CHAN_FM2FRQ2
emu_wrptr(sc, ch, EMU_CHAN_FM2FRQ2, 24); /* 1 Hz */
emu_wrptr(sc, v->vnum, EMU_CHAN_FM2FRQ2, 0);
emu_wrptr(sc, v->vnum, EMU_CHAN_FM2FRQ2, 0);
emu_wrptr(sc, ch, EMU_CHAN_FM2FRQ2, 24); /* 1 Hz */