aica/tima: slow TIMA interrupt from once every 1 counts to once every 3 counts

src/interpreter.cpp

@@ -249,11 +249,13 @@ void interrupt()
       break;
     }
     */
-    if (state.channel[ch].keyon > 128) {
+    const int keyon_tick = 254;
+    if (state.channel[ch].keyon > keyon_tick) {
       state.channel[ch].keyon -= 1;
     }
-    if (state.channel[ch].keyon == 128) {
+    else if (state.channel[ch].keyon == keyon_tick) {
       wait(); aica_sound.channel[ch].KYONB(1);
+      state.channel[ch].keyon -= 1;
     }
   }
   wait(); aica_sound.channel[0].KYONEX(1);
@@ -263,7 +265,7 @@ void interrupt()
   }
   for (int ch = 0; ch < 64; ch++) {
     int keyon = state.channel[ch].keyon;
-    if (keyon < 128 && keyon != 0) {
+    if (keyon != 0) {
       state.channel[ch].keyon -= 1;
     }
   }

src/scene/tracker/channel_status.cpp

@@ -64,6 +64,8 @@ void draw(ta_multiwriter& multi, int x, int y)
 
       int keyon = 128 * (state.channel[ch].keyon - 224) / 16;
       if (keyon < 0) keyon = 0;
+      if (keyon != 0)
+        printf("%d %d\n", state.channel[ch].keyon, keyon);
       uint32_t base_color = (keyon << 16) | (keyon << 8) | (keyon << 0);
       transfer_rectangle(multi.op,
                          xi, y, 1.0 / 10000.0,