Routines
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43729: Start Picture Mode When The Screen Is Idle
Used by the routines at 43716 and ProcessCharacterData.
When nothing is on screen, clears the picture buffer and selects picture mode.
StartPictureModeScreenIdle 43729 PUSH DE Save DE and jump to StartPictureModeScreenIdle_CheckDisplayMode if the command mode at 40996 is set.
43730 LD A,(40996)
43733 AND A
43734 JR NZ,StartPictureModeScreenIdle_CheckDisplayMode
43736 LD (43687),A Clear the state byte at 43687.
43739 LD HL,(41003) Read the word at ActiveTextPointer, save it and call ClearCoordinateBuffer to clear the co-ordinate buffer.
43742 PUSH HL
43743 CALL ClearCoordinateBuffer
43746 JR NZ,StartPictureModeScreenIdle_ClearBorrow Go to StartPictureModeScreenIdle_ClearBorrow when ClearCoordinateBuffer returns non-zero.
43748 LD A,(43687) Jump to StartPictureModeScreenIdle_ClearBorrow if the state byte at 43687 is set.
43751 AND A
43752 JR NZ,StartPictureModeScreenIdle_ClearBorrow
43754 LD A,2 Write 2 to the command mode at 40996.
43756 LD (40996),A
43759 POP HL Restore the saved pointer from the stack.
43760 PUSH IY Copy the character record from IY into HL.
43762 POP HL
43763 LD DE,24 Point HL at the co-ordinates 0024 bytes into the character record, and DE at the buffer at Buffer_CoordinateData.
43766 ADD HL,DE
43767 LD DE,43692
43770 EX DE,HL Swap the pointers, take 6 bytes and copy them.
43771 LD BC,6
43774 LDIR
43776 LD HL,(41001) Read the word at SavedTextPointer.
43779 LD (41003),HL Store it in the word at ActiveTextPointer and jump ahead to StartPictureModeScreenIdle_CheckDisplayMode to check display mode.
43782 JR StartPictureModeScreenIdle_CheckDisplayMode
StartPictureModeScreenIdle_ClearBorrow 43784 LD A,1 Write 1 to the command mode at 40996.
43786 LD (40996),A
43789 POP HL Restore the saved pointer from the stack.
43790 LD (41003),HL Store the pointer in the word at ActiveTextPointer.
StartPictureModeScreenIdle_CheckDisplayMode 43793 POP DE Restore the source from the stack.
43794 XOR A Clear the state byte at 43687 and call CheckDisplayMode to check display mode.
43795 LD (43687),A
43798 CALL CheckDisplayMode
43801 JR C,CopyDisplayIfNeeded_ReportDone Jump ahead to CopyDisplayIfNeeded_ReportDone if CheckDisplayMode finds the marker bit already clear.
43803 JR Z,StartPictureModeScreenIdle_TestBitLowByte Go to StartPictureModeScreenIdle_TestBitLowByte if bit 1 of the source is clear.
43805 CP 144 Jump ahead to SearchCommandHandlerTable if it is 144.
43807 JP Z,SearchCommandHandlerTable
43810 CP 160 Jump ahead to HandleClassAWord if it is 160.
43812 JP Z,HandleClassAWord
43815 BIT 3,E Jump ahead to ReadObjectProcessingFlag if bit 3 is clear.
43817 JR Z,ReadObjectProcessingFlag
43819 LD A,(40978) Jump to CopyDisplayIfNeeded_ReportDone if the pictures-enabled byte at 40978 is set.
43822 AND A
43823 JR NZ,CopyDisplayIfNeeded_ReportDone
43825 LD A,(40987) Jump to ReadObjectProcessingFlag if the initialised flag is set.
43828 AND A
43829 JR NZ,ReadObjectProcessingFlag
43831 LD A,(41005) Jump to CopyDisplayIfNeeded_ReportDone if the byte at SavedSourceByte is not 192.
43834 CP 192
43836 JR NZ,CopyDisplayIfNeeded_ReportDone
43838 LD A,176 Jump ahead to CopyDisplayIfNeeded_ReportDone if D is not 176.
43840 CP D
43841 JR NZ,CopyDisplayIfNeeded_ReportDone
43843 LD A,2 Leave 2 as the result.
43845 AND A Clear the borrow so the script reads the result as success.
43846 RET Return.
See whether bit 3 of the low byte of the source is set, then read the pointer at the object Processing Source Flag, then record the pointer in the object Processing Source Flag.
StartPictureModeScreenIdle_TestBitLowByte 43847 BIT 3,E Go to ApplySavedClause if bit 3 of this byte is clear.
43849 JP Z,ApplySavedClause
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