Everyone's a Wally: Routine at B7F9

B7F9: Routine at B7F9

Used by the routine at F177.
B7F9	PUSH AF	Stash AF, HL, BC and DE on the stack.
B7FA	PUSH HL
B7FB	PUSH BC
B7FC	PUSH DE
B7FD	EX DE,HL	Switch the DE and HL registers.
B7FE	PUSH HL	Stash HL on the stack.
B7FF	LD D,$FD	D=FD.
B801	LD E,L	E=L.
B802	LD L,H	L=H.
B803	LD H,$00	H=00.
B805	ADD HL,HL	HL*=(20)+DE.
B806	ADD HL,HL
B807	ADD HL,HL
B808	ADD HL,HL
B809	ADD HL,HL
B80A	ADD HL,DE
B80B	LD (HL),C	Write C to *HL.
B80C	POP HL	Restore HL from the stack.
B80D	LD DE,$5300	HL+=5300.
B810	ADD HL,DE	HL+=5300.
B811	EX DE,HL	Switch the DE and HL registers.
B812	LD L,A	Create an offset in HL.
B813	LD H,$00	Create an offset in HL.
B815	ADD HL,HL	HL*=08.
B816	ADD HL,HL
B817	ADD HL,HL
B818	LD BC,($B7E9)	HL+=*B7E9.
B81C	ADD HL,BC	HL+=*B7E9.
B81D	LDI	Write HL to DE, increment both DE and HL by one, and decrease BC by one.
B81F	DEC E	Decrease B by one.
B820	LD A,E	E+=20.
B821	ADD A,$20
B823	LD E,A
B824	JR NC,$B81D
B826	POP DE	Restore DE, BC, HL and AF from the stack.
B827	POP BC
B828	POP HL
B829	POP AF
B82A	RET	Return.