Back to Skool: Routine at 7C98

7C98: Raise the signal for a certain event

Used by the routine at F073 to raise the signal for the event identifier in A. In practice only event IDs 0x08-0x0C are used, which indicate to anyone listening that the teacher has arrived at the classroom door.

Input
A	Event identifier (0x08-0x0C) from the teacher's command list
H	Teacher's character number (0xC9-0xCC)

7C98

CALL $7C75

Convert the event ID into an appropriate bit mask (0x01, 0x02, 0x04, 0x08 or 0x10)

7C9B

OR (HL)

Merge the existing event flags in 7F81

This entry point is used by the (unused) routine at 7CA1.

7C9C

LD (HL),A

Set or reset the appropriate bit at 7F81

7C9D

EX DE,HL

Restore the character number to H

7C9E

RET