Routines
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25799: Handler: Update Time
Used by the routine at HandlerPlayer.
Adds one second to the time taken every 50 frames. The time is held as three BCD bytes from Time_1: hours (a single digit), minutes and seconds.
HandlerTime 25799 LD A,(23672) Fetch the frame counter from FRAMES.
25802 CP 50 Return if less than 50 frames (one second) have passed.
25804 RET C
25805 SUB 50 Take 50 frames off the frame counter.
25807 LD (23672),A Write the remaining frames back to FRAMES.
Update the time from the smallest unit upwards.
Handles the "seconds".
25810 LD HL,24115 Point HL at the seconds of the time (Time_3).
25813 LD A,(HL) Grab the seconds.
25814 INC A Add one second.
25815 DAA Convert to BCD and write seconds back to Time_3.
25816 LD (HL),A
25817 CP 96 Return unless seconds have reached 96.
25819 RET NZ
25820 LD (HL),0 Reset seconds to 0.
Handles the "minutes".
25822 DEC HL Point HL at the minutes of the time (Time_2).
25823 LD A,(HL) Grab the minutes.
25824 INC A Add one minute.
25825 DAA Convert to BCD and write minutes back to Time_2.
25826 LD (HL),A
25827 CP 96 Return unless minutes have reached 96.
25829 RET NZ
25830 LD (HL),0 Reset minutes to 0.
Handles the "hours".
25832 DEC HL Point HL at the hours of the time (Time_1).
25833 LD A,(HL) Grab the hours.
25834 INC A Add one hour.
25835 DAA Convert to BCD.
25836 AND %00001111 Keep only bits 0-3 (so the hours are a single digit).
25838 LD (HL),A Write hours back to Time_1.
25839 RET Return.
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