Tranz Am: Routine at 64C7

64C7: Handler: Update Time

Used by the routine at HandlerPlayer. Adds one second to the time taken every 32 frames. The time is held as three BCD bytes from Time_1: hours (a single digit), minutes and seconds.
HandlerTime	64C7	LD A,($5C78)	Fetch the frame counter from FRAMES.
	64CA	CP $32	Return if less than 32 frames (one second) have passed.
	64CC	RET C	Return if less than 32 frames (one second) have passed.
	64CD	SUB $32	Take 32 frames off the frame counter.
	64CF	LD ($5C78),A	Write the remaining frames back to FRAMES.
Update the time from the smallest unit upwards. Handles the "seconds".
	64D2	LD HL,$5E33	Point HL at the seconds of the time (Time_3).
	64D5	LD A,(HL)	Grab the seconds.
	64D6	INC A	Add one second.
	64D7	DAA	Convert to BCD and write seconds back to Time_3.
	64D8	LD (HL),A	Convert to BCD and write seconds back to Time_3.
	64D9	CP $60	Return unless seconds have reached 60.
	64DB	RET NZ	Return unless seconds have reached 60.
	64DC	LD (HL),$00	Reset seconds to 00.
Handles the "minutes".
	64DE	DEC HL	Point HL at the minutes of the time (Time_2).
	64DF	LD A,(HL)	Grab the minutes.
	64E0	INC A	Add one minute.
	64E1	DAA	Convert to BCD and write minutes back to Time_2.
	64E2	LD (HL),A	Convert to BCD and write minutes back to Time_2.
	64E3	CP $60	Return unless minutes have reached 60.
	64E5	RET NZ	Return unless minutes have reached 60.
	64E6	LD (HL),$00	Reset minutes to 00.
Handles the "hours".
	64E8	DEC HL	Point HL at the hours of the time (Time_1).
	64E9	LD A,(HL)	Grab the hours.
	64EA	INC A	Add one hour.
	64EB	DAA	Convert to BCD.
	64EC	AND %00001111	Keep only bits 0-3 (so the hours are a single digit).
	64EE	LD (HL),A	Write hours back to Time_1.
	64EF	RET	Return.