Technician Ted: Routine at 5D80

5D80: Initialize display

This routine takes the text starting at 5E55 and scrolls it onto screen, accompanied by white noises
5D80	DI
5D81	LD B,$20	Scroll for 20 characters
5D83	XOR A
5D84	INC A
5D85	LD ($5E08),A	Store current offset of text
5D88	PUSH BC
5D89	LD A,($5E08)
5D8C	LD E,A
5D8D	LD D,$00
5D8F	LD HL,$5E75	First line
5D92	SBC HL,DE
5D94	PUSH HL
5D95	LD DE,$4000	Put it on the top of the screen
5D98	CALL $5DE7	Scroll it
5D9B	POP HL
5D9C	LD DE,$0060	Third line
5D9F	ADD HL,DE	Third line
5DA0	LD DE,$50C0	Second bottom line of screen
5DA3	CALL $5DE7	Scroll it
5DA6	LD A,($5E08)
5DA9	LD E,A
5DAA	LD D,$00
5DAC	LD HL,$5E75	Second line
5DAF	ADD HL,DE
5DB0	PUSH HL
5DB1	LD DE,$4020	Second to top line of screen
5DB4	CALL $5DE7	Scroll it
5DB7	POP HL
5DB8	LD DE,$0060	Fourth line
5DBB	ADD HL,DE	Fourth line
5DBC	LD DE,$50E0	Bottom line of screen
5DBF	CALL $5DE7	Scroll it
5DC2	LD HL,$5E08	Get current text offset
5DC5	INC (HL)	Move on by one
5DC6	CALL $5E09	Play a sound
5DC9	POP BC
5DCA	DJNZ $5D88	Onto the next character
5DCC	LD HL,$5AFA	Set 3 characters starting at 5AFA to be red-on white. This means the timer gets displayed as inverse to everything else.
5DCF	LD B,$03
5DD1	LD (HL),$7A
5DD3	INC HL
5DD4	DJNZ $5DD1
5DD6	RET