![]() |
Routines |
H | Character number of teacher (201-204) |
26639 | CALL 28658 | Collect information about board |
26642 | LD L,11 | 32 distinct actions are needed to wipe the board; store this counter in byte 11 of the teacher's buffer |
26644 | LD (HL),32 | |
26646 | INC L | L=12 |
26647 | LD A,E | A=x-coordinate of left-hand end of board |
26648 | ADD A,7 | A=x-coordinate of right-hand end of board |
26650 | LD (HL),A | Store this in byte 12 of the teacher's buffer |
26651 | INC L | Place y-coordinate of top line of board in byte 13 of the teacher's buffer |
26652 | LD (HL),D | |
26653 | INC L | And the board identifier (LSB of 32596, 32602, 32608, 32614 or 32620) in byte 14 |
26654 | LD (HL),B | |
26655 | LD L,9 | Change the routine address in bytes 9 and 10 of the teacher's buffer to 26659 (below) |
26657 | LD (HL),35 | |
26659 | LD L,11 | Byte 11 holds the board-wiping action counter |
26661 | DEC (HL) | Decrement the counter |
26662 | JP P,26678 | Jump if the board has not yet been fully wiped |
26665 | LD L,14 | Collect the board identifier in L |
26667 | LD L,(HL) | |
26668 | LD H,127 | HL now points to the board's buffer |
26670 | LD (HL),0 | Signal that the board has been wiped by zeroing the first two bytes of the blackboard's buffer |
26672 | INC L | |
26673 | LD (HL),0 | |
26675 | JP 25488 | Now the job's been done, remove the address of this routine from bytes 9 and 10 of the teacher's buffer |
26678 | CALL 25012 | Update SRB for the teacher's current animatory state and location |
26681 | AND 120 | A=teacher's base animatory state |
26683 | LD L,11 | Point HL at the board-wiping action counter |
26685 | BIT 0,(HL) | Is the teacher midstride or wiping (arm up)? |
26687 | JR Z,26742 | Jump if so |
26689 | BIT 1,(HL) | Are we ready for a wipe action? |
26691 | JR Z,26697 | Jump if so |
26693 | INC A | A=animatory state of teacher midstride |
26694 | JP 24880 | Update SRB for the teacher's new animatory state |
26697 | ADD A,7 | A=animatory state of teacher with arm up |
26699 | CALL 24880 | Update SRB for the teacher's new animatory state |
26702 | LD L,12 | Collect the x-coordinate of part of board to be wiped into E |
26704 | LD E,(HL) | |
26705 | DEC (HL) | Decrease this x-coordinate ready for the next wipe |
26706 | INC L | Collect the y-coordinate of the top line of the blackboard into D |
26707 | LD D,(HL) | |
26708 | CALL 26380 | Update SRB for the top line of the blackboard |
26711 | INC D | D=y-coordinate of the bottom line of the blackboard |
26712 | CALL 26380 | Update SRB for the bottom line of the blackboard |
26715 | LD A,D | Prepare H for picking up skool UDG base address LSBs later |
26716 | ADD A,160 | |
26718 | LD H,A | |
26719 | LD D,181 | Pick up the Q value (0<=Q<=143) for the lower blackboard tile being wiped from page 181 in L |
26721 | LD A,(DE) | |
26722 | LD L,A | |
26723 | LD A,(HL) | Collect the LSB of the base address of the skool UDG for this blackboard tile in L |
26724 | LD L,A | |
26725 | SUB 8 | Set E to the LSB of the base address of the skool UDG for the upper blackboard tile |
26727 | LD E,A | |
26728 | LD H,128 | The base page for all blackboard tile UDGs is 128 |
26730 | LD D,H | |
26731 | LD B,8 | 8 lines per character square |
26733 | LD A,255 | 255=blank blackboard byte |
26735 | LD (HL),A | Clear a pixel line in the skool UDG for the lower blackboard tile |
26736 | LD (DE),A | Clear a pixel line in the skool UDG for the upper blackboard tile |
26737 | INC H | Next pixel row of the lower blackboard tile UDG |
26738 | INC D | Next pixel row of the upper blackboard tile UDG |
26739 | DJNZ 26735 | Jump back until the two blackboard tile UDGs have been cleared |
26741 | RET |
26742 | BIT 1,(HL) | Is the teacher wiping? |
26744 | JR Z,26747 | Jump if so |
26746 | DEC E | Teacher is midstride, so now move him one space to the left |
26747 | JP 24880 | Update SRB for the teacher's new animatory state and location |