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Routines |
| Prev: 9DA7 | Up: Map | Next: 9E4F |
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Used by the routine at MainLoop.
Starts a program packet flying from a program transmitter, unless one is already on its way. It queues the messages "PROGRAM SENT FROM" and "SECTOR n".
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| SendProgramPacket | 9DFE | LD A,($9770) | Fetch the type of the program packet (entity 0E). | |||||
| 9E01 | AND A | Return if it is already in use. | ||||||
| 9E02 | RET NZ | |||||||
| 9E03 | PUSH HL | Save the address of the transmitter... | ||||||
| 9E04 | PUSH HL | ...twice. | ||||||
| 9E05 | LD HL,$9770 | Point HL at ProgramPacketEntity. | ||||||
| 9E08 | LD B,$10 | Clear all 10 bytes of the entity. | ||||||
| SendProgramPacket_ClearEntity | 9E0A | LD (HL),$00 | Zero a byte. | |||||
| 9E0C | INC HL | Move on to the next byte. | ||||||
| 9E0D | DJNZ SendProgramPacket_ClearEntity | Loop back until the entity has been cleared. | ||||||
| 9E0F | POP HL | Restore the address of the transmitter. | ||||||
| 9E10 | LD IX,$9770 | Point IX at ProgramPacketEntity. | ||||||
| 9E14 | LD (IX+$00),$6E | Set the type of the entity to 6E, the first sprite of the program packet. | ||||||
| 9E18 | LD DE,$C515 | Point DE at Map. | ||||||
| 9E1B | SBC HL,DE | Subtract it to find the offset of the transmitter. | ||||||
| 9E1D | LD A,L | Fetch the low byte of the offset. | ||||||
| 9E1E | AND $3F | The column is in the low six bits. | ||||||
| 9E20 | ADD HL,HL | Multiply the offset by four... | ||||||
| 9E21 | ADD HL,HL | |||||||
| 9E22 | LD L,A | ...and keep the column in L. | ||||||
| 9E23 | LD A,H | The row is in the high byte, in the low six bits. | ||||||
| 9E24 | AND $3F | Limit the row to 00-3F... | ||||||
| 9E26 | LD H,A | ...and keep it in H. | ||||||
| 9E27 | LD A,($9617) | Fetch the random number... | ||||||
| 9E2A | AND $3F | ...limited to 00-3F... | ||||||
| 9E2C | LD (IX+$07),A | ...as a timer for the program packet. | ||||||
| 9E2F | LD (IX+$02),L | Set the X cell of the packet to that of the transmitter. | ||||||
| 9E32 | LD (IX+$04),H | Set the Y cell of the packet to that of the transmitter. | ||||||
| 9E35 | PUSH DE | Save the registers. | ||||||
| 9E36 | PUSH BC | Save the registers. | ||||||
| 9E37 | LD DE,$0002 | Queue message 02, "PROGRAM SENT FROM"... | ||||||
| 9E3A | CALL QueueMessage | ...using QueueMessage. | ||||||
| 9E3D | CALL FindSector | Find the sector that the packet is in using FindSector. | ||||||
| 9E40 | LD E,$01 | Queue message 01, "SECTOR n"... | ||||||
| 9E42 | CALL QueueMessage | ...using QueueMessage. | ||||||
| 9E45 | LD HL,$0105 | Start effect 01 (five tones). | ||||||
| 9E48 | LD ($9688),HL | Store the length and the effect number for PlaySoundStep. | ||||||
| 9E4B | POP BC | Restore the registers. | ||||||
| 9E4C | POP DE | Restore the registers. | ||||||
| 9E4D | POP HL | Restore the address of the transmitter. | ||||||
| 9E4E | RET | Return. | ||||||
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