| Routines

63B0: Jump to an interruptible subcommand

Used by the routines at 6464 and 7D36. Copies the routine address from BC into bytes 0x09 and 0x0A of the character's buffer (thus setting the interruptible subcommand), and then jumps to that routine.
Input
H | Character number (0xB7-0xD6)
BC | 63ED, 6438, 644D or F54A
63B0 | PUSH BC | Push the routine address in BC onto the stack
63B1 | LD L,$09 | Point HL at byte 0x09 of the character's buffer
63B3 | JR $63AC | Place the interruptible subcommand routine address into bytes 0x09 and 0x0A of the character's buffer, then jump to it