Routines
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24692: Run Script Table
Used by the routine at ObeyCommand.
Walks a bytecode table. A line whose verb and noun match is executed; a failed condition or a bit-6 action stops the line. 127 ends the table.
The ordinary command scripts live at CommandScripts and are marked by a clear script-set flag.
RunScripts 24692 LD HL,39508 Select the ordinary scripts. The high-priority entry joins here.
24695 XOR A
24696 LD (23446),A
This entry point is used by the routine at RunPriorityScripts.
RunScripts_Line 24699 PUSH HL Keep the line pointer in DE while HL walks it.
24700 POP DE
24701 XOR A No line has matched yet, and no condition has failed.
24702 LD (23417),A
24705 LD (24266),A
24708 CALL MatchCommand Call MatchCommand to test the verb and noun.
24711 JR RunScripts_Next The next byte is a condition or an action.
RunScripts_Failed 24713 XOR A A failed line is abandoned and the next one is tried.
24714 LD (24266),A
24717 CALL SkipLine
RunScripts_Next 24720 LD A,H Return at the 127 end marker.
24721 OR L
24722 RET Z
24723 BIT 7,(HL) Bit 7 on the current byte starts the actions.
24725 JR NZ,RunScripts_Matched
A condition byte, shifted, picks a routine from 26571. The object byte in front of it is looked up in ObjectLocations.
RunScripts_Condition 24727 LD A,(HL) Shift the condition number so it indexes a word.
24728 SLA A
24730 LD IX,26571 Index the condition table at 26571.
24734 LD C,A
24735 LD B,0
24737 ADD IX,BC
24739 LD A,(IX+0) Plant that routine over the call at 24769.
24742 LD (24770),A
24745 LD A,(IX+1)
24748 LD (24771),A
24751 PUSH HL The next bytecode byte is the object number.
24752 INC HL
24753 LD A,(HL)
24754 LD C,A
24755 LD IX,24010 Point at that object's location in ObjectLocations.
24759 ADD IX,BC
24761 LD B,A The location itself is what the condition compares.
24762 LD A,(IX+0)
24765 LD C,A
24766 INC HL The byte after the object is the condition's parameter.
24767 LD A,(HL)
24768 PUSH DE
24769 CALL 6 The condition routine returns normally when it passes, or sets ConditionFailed when it fails.
24772 POP DE
24773 POP HL
24774 CALL SkipCondition
24777 LD A,(24266) A failure skips the rest of this line.
24780 OR A
24781 JR NZ,RunScripts_Failed
24783 BIT 7,(HL) Otherwise keep testing while bit 7 is clear.
24785 JR Z,RunScripts_Condition
The line matched. Remember that, and perform each action until one asks to stop.
RunScripts_Matched 24787 LD A,1 Remember that a line matched.
24789 LD (23417),A
RunScripts_NextAction 24792 LD A,(23430) The word slot is clear, so nothing to forget.
24795 OR A
24796 JR Z,RunScripts_Action
24798 XOR A The first matched line of a command clears WordSlot.
24799 LD (23430),A
RunScripts_Action 24802 BIT 6,(HL) Bit 6 asks the runner to stop after this action.
24804 JR Z,RunScripts_Do
24806 LD A,1
24808 LD (24266),A
RunScripts_Do 24811 LD A,(HL) Keep the action number in the low six bits and double it.
24812 AND 63
24814 SLA A
24816 LD IX,27349 Index from the word inside 27348. Action 0 is the beeper operand; the routines start at ActionTable.
24820 LD C,A
24821 LD B,0
24823 ADD IX,BC
24825 LD A,(IX+0) Plant that routine over the call at 24855.
24828 LD (24856),A
24831 LD A,(IX+1)
24834 LD (24857),A
24837 PUSH HL The next bytecode byte is the object number.
24838 INC HL
24839 LD A,(HL)
24840 LD IX,24010 Point at that object's location in ObjectLocations.
24844 LD C,A
24845 ADD IX,BC
24847 LD B,A The location itself is passed to the action.
24848 LD A,(IX+0)
24851 LD C,A
24852 INC HL The byte after the object is the action's parameter.
24853 LD A,(HL)
24854 PUSH DE
24855 CALL 6 Call the patched action.
24858 POP DE Restore the line pointer and the table pointer.
24859 POP HL
24860 CALL SkipAction Call SkipAction to step past the action.
24863 LD A,(24266) Stop the table when the action raised ConditionFailed.
24866 OR A
24867 RET NZ
24868 BIT 7,(HL) Bit 7 continues this line's next action.
24870 JR NZ,RunScripts_NextAction
24872 JP RunScripts_Failed Jump to RunScripts_Failed to start the next line.
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