Routines
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B950: Initialise Explosion
Copy an 8-byte explosion template into Explosion_Slot, which starts a sound. The entry point at InitialiseExplosion_Copy takes the template address in HL.
There are five templates. The first is read by TickWaveDuration (type A5) and the other four by TickWaveTable (type A1).
InitialiseExplosion B950 LD HL,$B95C HL=Explosion_Template_1.
InitialiseExplosion_Copy B953 LD DE,$6060 DE=Explosion_Slot.
B956 LD BC,$0008 Copy 08 bytes from HL to DE.
B959 LDIR
B95B RET Return.
Template for TickWaveDuration. It plays one note on each pass, starting from the pitch below and counting down to 01 so the sound rises over 27 notes. Nothing calls InitialiseExplosion, so this one is never used. The copy at InitialiseExplosion_Copy takes four more bytes than this, which are the first instructions at Copy_Explosion_Template, but TickWaveDuration never reads them.
Explosion_Template_1 B95C DEFB $A5 Actor type, handled by TickWaveDuration.
B95D DEFB $20 Not read by TickWaveDuration.
B95E DEFB $08 Repeat count: each note is played 08 times.
B95F DEFB $28 Starting pitch.
This entry point is used by the routines at Handler_PlayerShot and Handler_Missile_ConvertExploding.
Copy_Explosion_Template B960 LD HL,$B965 HL=Explosion_Template_2.
B963 JR InitialiseExplosion_Copy Jump to InitialiseExplosion_Copy.
Template for TickWaveTable: seven notes of falling pitch, each played 08 times.
Explosion_Template_2 B965 DEFB $A1 Actor type, handled by TickWaveTable.
B966 DEFB $08 Counter: a value of 08 gives seven notes.
B967 DEFW $B96A Address of the pitch table minus one.
B969 DEFB $08 Repeat count: each note is played 08 times.
B96A DEFB $00 Index 00 of the pitch table, which is never read.
B96B DEFB $78,$70,$68,$60,$58,$50,$48 Pitch table, played from the last byte back to the first.
B972 DEFB $40 Never played, as the counter reaches zero first.
InitialiseExplosion_2 B973 LD HL,$B978 HL=Explosion_Template_Burst.
B976 JR InitialiseExplosion_Copy Jump to InitialiseExplosion_Copy.
Template for TickWaveTable: seven notes of rising pitch, each played 10 times.
Explosion_Template_Burst B978 DEFB $A1 Actor type, handled by TickWaveTable.
B979 DEFB $08 Counter: a value of 08 gives seven notes.
B97A DEFW $B97D Address of the pitch table minus one.
B97C DEFB $10 Repeat count: each note is played 10 times.
B97D DEFB $00 Index 00 of the pitch table, which is never read.
B97E DEFB $40,$48,$50,$58,$60,$60,$68 Pitch table, played from the last byte back to the first.
B985 DEFB $70 Never played, as the counter reaches zero first.
InitialiseExplosion_3 B986 LD HL,$B98B HL=Explosion_Template_3.
B989 JR InitialiseExplosion_Copy Jump to InitialiseExplosion_Copy.
Template for TickWaveTable: fifteen notes that swap between two pitches in runs of up to four, each note played 06 times.
Explosion_Template_3 B98B DEFB $A1 Actor type, handled by TickWaveTable.
B98C DEFB $10 Counter: a value of 10 gives fifteen notes.
B98D DEFW $B990 Address of the pitch table minus one.
B98F DEFB $06 Repeat count: each note is played 06 times.
B990 DEFB $00 Index 00 of the pitch table, which is never read.
B991 DEFB $40,$40,$40,$40,$50,$50,$50,$50 Pitch table, played from the last byte back to the first.
B999 DEFB $40,$40,$40,$40,$50,$50,$50
B9A0 DEFB $50 Never played, as the counter reaches zero first.
InitialiseExplosion_4 B9A1 LD HL,$B9A6 HL=Explosion_Template_4.
B9A4 JR InitialiseExplosion_Copy Jump to InitialiseExplosion_Copy.
Template for TickWaveTable: fifteen notes of falling pitch, each played 06 times.
Explosion_Template_4 B9A6 DEFB $A1 Actor type, handled by TickWaveTable.
B9A7 DEFB $10 Counter: a value of 10 gives fifteen notes.
B9A8 DEFW $B9AB Address of the pitch table minus one.
B9AA DEFB $06 Repeat count: each note is played 06 times.
B9AB DEFB $00 Index 00 of the pitch table, which is never read.
B9AC DEFB $50,$4E,$4C,$4A,$48,$46,$44,$42 Pitch table, played from the last byte back to the first.
B9B4 DEFB $40,$3E,$3C,$3A,$38,$36,$34
B9BB DEFB $32 Never played, as the counter reaches zero first.
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