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Routines |
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The sound with index A will become the pending sound if the currently pending sound index is either zero, or of higher index than A (i.e. lower priority).
On entering this routine, register L will have a pseudo-random (undefined) value due to the register's use in other routines.
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| 59722 | CALL 59613 | Set pending sound index to A if it is currently zero, or lower priority | ||||||||
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This entry point is used by the routine at 34438.
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| 59725 | LD A,(34273) | Load A with index of pending sound and if this is zero then return | ||||||||
| 59728 | OR A | |||||||||
| 59729 | RET Z | |||||||||
| 59730 | DEC A | Decrease A to give zero-based sound index | ||||||||
| 59731 | PUSH IX | Store IX | ||||||||
| 59733 | LD IX,59635 | Point IX at second byte of first entry in sound parameters table | ||||||||
| 59737 | ADD A,A | Load BC with eight times pending sound index | ||||||||
| 59738 | ADD A,A | |||||||||
| 59739 | ADD A,A | |||||||||
| 59740 | LD C,A | |||||||||
| 59741 | LD B,0 | |||||||||
| 59743 | ADD IX,BC | Add BC to IX as offset to point to sound data for pending sound | ||||||||
| 59745 | LD A,B | Set index of pending sound to zero | ||||||||
| 59746 | LD (34273),A | |||||||||
| 59749 | LD C,(IX+0) | Load C with outer repeat count | ||||||||
| 59752 | LD B,(IX+1) | Load B with inner repeat count | ||||||||
| 59755 | LD E,(IX+2) | Load E with delay constant E | ||||||||
| 59758 | LD D,(IX+3) | Load D with delay constant D | ||||||||
| 59761 | LD H,(IX+6) | Load H with most significant byte of pseudo-random address | ||||||||
| 59764 | PUSH BC | Store BC (B = inner repeat count, C = outer repeat count) | ||||||||
| 59765 | LD A,(34217) | Set speaker state and border colour | ||||||||
| 59768 | SET 4,A | |||||||||
| 59770 | OUT (254),A | |||||||||
| 59772 | LD B,D | Pause for period D | ||||||||
| 59773 | NOP | |||||||||
| 59774 | DJNZ 59773 | |||||||||
| 59776 | BIT 7,H | If no-pause flag is set then skip ahead to 59794 | ||||||||
| 59778 | JR NZ,59794 | |||||||||
| 59780 | LD B,(HL) | Load B with value from pseudo-random address | ||||||||
| 59781 | INC HL | Advance HL | ||||||||
| 59782 | BIT 0,(IX+0) | Pause for period B | ||||||||
| 59786 | NOP | |||||||||
| 59787 | NOP | |||||||||
| 59788 | NOP | |||||||||
| 59789 | NOP | |||||||||
| 59790 | NOP | |||||||||
| 59791 | NOP | |||||||||
| 59792 | DJNZ 59782 | |||||||||
| 59794 | RES 4,A | Reset speaker state and set border colour | ||||||||
| 59796 | OUT (254),A | |||||||||
| 59798 | LD B,E | Pause for period E | ||||||||
| 59799 | NOP | |||||||||
| 59800 | DJNZ 59799 | |||||||||
| 59802 | LD A,(IX+4) | Adjust value of delay constant D | ||||||||
| 59805 | ADD A,D | |||||||||
| 59806 | LD D,A | |||||||||
| 59807 | LD A,(IX+5) | Adjust value of delay constant E | ||||||||
| 59810 | ADD A,E | |||||||||
| 59811 | LD E,A | |||||||||
| 59812 | POP BC | Restore BC (B = inner repeat count, C = outer repeat count) | ||||||||
| 59813 | DJNZ 59764 | Decrease repeat count and loop back to 59764 | ||||||||
| 59815 | DEC C | Decrease outer repeat count | ||||||||
| 59816 | JR NZ,59752 | If non-zero (i.e. more repeats to process) then loop back to 59752 | ||||||||
| 59818 | POP IX | Restore IX | ||||||||
| 59820 | RET | Return | ||||||||
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