Routines
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25960: Play Music
Used by the routines at StartGame, HandleCake and HandleFallingCharlie.
Plays a tune using the BEEPER routine. Each byte of the tune is a note number, in bits 0-4, which chooses the pitch and length of the note from the table at MusicNotes. The tune ends at the byte 255.
Input
DE Address of the tune
PlayMusic 25960 LD A,(DE) Fetch the next note of the tune.
25961 CP 255 Return if the end of the tune (255) has been reached.
25963 RET Z
25964 AND %00011111 Keep only bits 0-4 (the note number).
25966 DEC A Decrease the note number by one (note numbers start from 1).
25967 SLA A Double the note number, as there are two bytes for each note.
25969 LD C,A Use the result as an offset into the table of notes.
25970 LD B,0
25972 LD HL,26004 Find the entry for the note in MusicNotes.
25975 ADD HL,BC
25976 PUSH DE Stash the pointer to the tune on the stack.
25977 LD A,(HL) Fetch the pitch of the note.
25978 INC HL Increment HL by one.
25979 LD E,(HL) Fetch the length of the note into E.
25980 LD D,0 Set the high byte of the length to 0.
25982 LD L,A Put the pitch in L.
25983 LD H,0 Set the high byte of the pitch to 0.
25985 SLA L Multiply the pitch by 4 for the BEEPER routine.
25987 RL H
25989 SLA L
25991 RL H
25993 PUSH IX Stash IX on the stack.
25995 CALL 949 Play the note using BEEPER.
25998 POP IX Restore IX from the stack.
26000 POP DE Restore the pointer to the tune from the stack.
26001 INC DE Move on to the next note of the tune.
26002 JR PlayMusic Jump back to PlayMusic to play the next note (the tune only ends when the terminator is reached).
View the equivalent code in;
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