| Routines

6200: Make a sound effect

Used by the routines at 66F0 (to make the sound effect of Sam being shot) and 6FE6 (to make the sound effect of a sniper firing).
Input
A | Initial border colour
D | Pitch adjustment
E | Initial pitch
6200 | ADD A,$11 | Flip bit 4 of A and increment the border colour in bits 0-2
6202 | AND $17 | Retain only bits 0-2 and 4
6204 | OUT ($FE),A | Change the border colour and speaker state
6206 | LD B,E | Perform the pitch delay
6207 | DJNZ $6207
6209 | LD B,A | Save A briefly
620A | LD A,E | Adjust the pitch delay for the next pass
620B | ADD A,D
620C | LD E,A
620D | LD A,B | Restore A
620E | JR NZ,$6200 | Jump back unless the pitch delay is now 0
6210 | RET |