Used by the routine at CREATURE_UPDATE.

Twelve waves at a pitch from BLIP_PITCHES picked by the turn counter's low four bits, if the record was drawn last turn; the flag is cleared, so it sounds once for each time the thing is on the screen. The creature's update calls it (CREATURE_UPDATE). Pentagram has the same bytes, unused.

The villains' update (VILLAIN_WANDER) enters at BLIP_FROM_TABLE, meaning to give each villain its own sixteen pitches from VILLAIN_PITCHES, and misses twice. It loads the table's address into HL, which this routine overwrites with the turn's four bits before adding BC; and the offset it puts in BC, the graphic turned left two bits and cut to its top four, keeps graphic bit 5 as well as the kind, so it is $80, $90, $A0 or $B0 rather than 0 to 48. So a villain's blip is pitched by bytes of the ROM, from $0080 to $00BF, and the four villains' tables are never read (range 4's simulator run saw the villains read their pitches at ROM addresses in each of those four sixteens).