Routines| H | Character number of teacher (201-204) |
| 26639 | CDF26F | CALL 28658 | Collect information about board |
| 26642 | 2E0B | LD L,11 | |
| 26644 | 3620 | LD (HL),32 | 32 distinct actions needed to wipe board |
| 26646 | 2C | INC L | |
| 26647 | 7B | LD A,E | A=x-coordinate of left-hand end of board |
| 26648 | C607 | ADD A,7 | A=x-coordinate of right-hand end of board |
| 26650 | 77 | LD (HL),A | Store this in byte 12 of the teacher's buffer |
| 26651 | 2C | INC L | |
| 26652 | 72 | LD (HL),D | Place y-coordinate of top line of board in byte 13 |
| 26653 | 2C | INC L | |
| 26654 | 70 | LD (HL),B | And the board identifier (84, 90, 96, 102, 108) in byte 14 |
| 26655 | 2E09 | LD L,9 | Change the address in byte 9 and 10 of the buffer to 26659 (below) |
| 26657 | 3623 | LD (HL),35 | |
| 26659 | 2E0B | LD L,11 | |
| 26661 | 35 | DEC (HL) | |
| 26662 | F23668 | JP P,26678 | Jump if board has not yet been fully wiped |
| 26665 | 2E0E | LD L,14 | |
| 26667 | 6E | LD L,(HL) | L=board identifier (84, 90, 96, 102, 108) |
| 26668 | 267F | LD H,127 | HL now points to the board's buffer |
| 26670 | 3600 | LD (HL),0 | Signal that the board has been wiped |
| 26672 | 2C | INC L | |
| 26673 | 3600 | LD (HL),0 | |
| 26675 | C39063 | JP 25488 | Now the job's been done, blank out the routine address at bytes 9 and 10 of the teacher's buffer |
| 26678 | CDB461 | CALL 25012 | Update SRB for teacher's current animatory state and location |
| 26681 | E678 | AND 120 | Keep bits 3-6 of the teacher's animatory state |
| 26683 | 2E0B | LD L,11 | Point HL at the board-wiping action counter |
| 26685 | CB46 | BIT 0,(HL) | Is the teacher midstride or wiping (arm up)? |
| 26687 | 2835 | JR Z,26742 | Jump if so |
| 26689 | CB4E | BIT 1,(HL) | Are we ready for a wipe action? |
| 26691 | 2804 | JR Z,26697 | Jump if so |
| 26693 | 3C | INC A | A=animatory state of teacher midstride |
| 26694 | C33061 | JP 24880 | Update SRB for teacher's new animatory state |
| 26697 | C607 | ADD A,7 | A=animatory state of teacher with arm up |
| 26699 | CD3061 | CALL 24880 | Update SRB for teacher's new animatory state |
| 26702 | 2E0C | LD L,12 | |
| 26704 | 5E | LD E,(HL) | E=x-coordinate of next part of board to be wiped |
| 26705 | 35 | DEC (HL) | |
| 26706 | 2C | INC L | |
| 26707 | 56 | LD D,(HL) | D=y-coordinate of top line of blackboardboard |
| 26708 | CD0C67 | CALL 26380 | Update SRB for the top line of the blackboard |
| 26711 | 14 | INC D | D=y-coordinate of bottom line of blackboard |
| 26712 | CD0C67 | CALL 26380 | Update SRB for the bottom line of the blackboard |
| 26715 | 7A | LD A,D | |
| 26716 | C6A0 | ADD A,160 | |
| 26718 | 67 | LD H,A | |
| 26719 | 16B5 | LD D,181 | |
| 26721 | 1A | LD A,(DE) | |
| 26722 | 6F | LD L,A | |
| 26723 | 7E | LD A,(HL) | |
| 26724 | 6F | LD L,A | |
| 26725 | D608 | SUB 8 | |
| 26727 | 5F | LD E,A | |
| 26728 | 2680 | LD H,128 | |
| 26730 | 54 | LD D,H | |
| 26731 | 0608 | LD B,8 | 8 lines per character square |
| 26733 | 3EFF | LD A,255 | 255=blank blackboard byte |
| 26735 | 77 | LD (HL),A | Clear a pixel line on the bottom row of the board |
| 26736 | 12 | LD (DE),A | Clear a pixel line on the top row of the board |
| 26737 | 24 | INC H | |
| 26738 | 14 | INC D | |
| 26739 | 10FA | DJNZ 26735 | Next pixel line |
| 26741 | C9 | RET |
| 26742 | CB4E | BIT 1,(HL) | Is the teacher wiping? |
| 26744 | 2801 | JR Z,26747 | Jump if so |
| 26746 | 1D | DEC E | Teacher is midstride, so now move him one space to the left |
| 26747 | C33061 | JP 24880 | Update SRB for teacher's new location |