| Routines

28658: Collect the identifier and coordinates of a blackboard that will be wiped

Used by the routine at 26639 to collect information about the blackboard that is going to be wiped by a teacher. Returns with B holding the blackboard identifier (the LSB of 32596, 32602, 32608, 32614 or 32620), and DE holding the coordinates of the top left-hand square of the board.
Input
H | Teacher's character number (201-204)
28658 | LD A,12 | Change the instruction at 26476 to ADD A,12 (for the purpose of this routine, a teacher is considered to be standing next to a blackboard if he's within 12 spaces to the right of its left edge)
28660 | LD (26477),A
28663 | CALL 26453 | Collect information about the blackboard the teacher is standing next to
28666 | LD A,4 | Change the instruction at 26476 back to ADD A,4
28668 | LD (26477),A
28671 | RET |