Routines| DE | 16384 (from 63553) or 16415 (from 63561) |
| 63512 | 0600 | LD B,0 | |
| 63514 | D9 | EXX | |
| 63515 | 0E15 | LD C,21 | 21 rows on screen (3 at bottom are fixed) |
| 63517 | 0608 | LD B,8 | 8 pixel lines per row of screen |
| 63519 | D9 | EXX | |
| 63520 | 62 | LD H,D | |
| 63521 | 6B | LD L,E |
| 63522 | 2C | INC L |
| 63522 | 2D | DEC L |
| 63523 | 7B | LD A,E | |
| 63524 | 0E1F | LD C,31 | 31 bytes to shift per pixel line |
| 63526 | EDB0 | LDIR | Shift to the left |
| 63526 | EDB8 | LDDR | Shift to the right |
| 63528 | 5F | LD E,A | |
| 63529 | 14 | INC D | Point DE at first (or last) byte of next pixel line in this row |
| 63530 | D9 | EXX | |
| 63531 | 10F2 | DJNZ 63519 | Shift the remaining pixel lines in this row |
| 63533 | D9 | EXX | |
| 63534 | 7B | LD A,E | |
| 63535 | C620 | ADD A,32 | |
| 63537 | 5F | LD E,A | |
| 63538 | 3804 | JR C,63544 | |
| 63540 | 7A | LD A,D | |
| 63541 | D608 | SUB 8 | |
| 63543 | 57 | LD D,A | |
| 63544 | D9 | EXX | |
| 63545 | 0D | DEC C | |
| 63546 | 20E1 | JR NZ,63517 | Jump back until all 21 rows have been shifted |
| 63548 | D9 | EXX | |
| 63549 | 3AFF7F | LD A,(32767) | A=column of play area (that was) at far left of screen |
| 63552 | C9 | RET |