Routines
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D8AD: Read A Command Line
Used by the routine at ReadCommandLine.
Reads a command line. Prints a prompt and stores the text at 5B00.
ReadCommandLine_CommandLinePrints D8AD LD A,$3E Print character 3E through Print_Character.
D8AF CALL Print_Character
D8B2 LD A,$20 Take a space and print it through Print_Character.
D8B4 CALL Print_Character
D8B7 LD HL,$5B00 Take the line buffer.
D8BA LD B,$80
ReadCommandLine_Loop D8BC LD A,$01 Mark the command line as started.
D8BE LD ($D897),A
D8C1 LD C,$00
This entry point is used by the routine at IgnoreInputUntilGameHasStarted.
ReadCommandLine_CompareLocationData D8C3 CALL WaitForKeyWithTimeout Go to IgnoreInputUntilGameHasStarted_InputPrintCharacter if WaitForKeyWithTimeout returns zero.
D8C6 JP Z,IgnoreInputUntilGameHasStarted_InputPrintCharacter
D8C9 BIT 7,B Jump ahead to ReadCommandLine_TestMarkerClear if bit 7 is clear.
D8CB JR Z,ReadCommandLine_TestMarkerClear
D8CD CP $40 Jump ahead to IgnoreInputUntilGameHasStarted if the command is 40.
D8CF JP Z,IgnoreInputUntilGameHasStarted
ReadCommandLine_TestMarkerClear D8D2 BIT 0,C Call MapCursorKeys if bit 0 of C is clear.
D8D4 CALL Z,MapCursorKeys
D8D7 LD C,$01 Jump ahead to ReadCommandLine_TestBackspacePrintedBackspace if the input is not 18.
D8D9 CP $18
D8DB JR NZ,ReadCommandLine_TestBackspacePrintedBackspace
D8DD CALL DeleteInputCharacter Delete the last input character and go back to ReadCommandLine_Loop.
D8E0 JR ReadCommandLine_Loop
A backspace is printed as a backspace unless the top bit of the count is set.
ReadCommandLine_TestBackspacePrintedBackspace D8E2 CP $08 Jump ahead to ReadCommandLine_TestQuotationMarkToggles if the command is not 08.
D8E4 JR NZ,ReadCommandLine_TestQuotationMarkToggles
D8E6 BIT 7,B Jump back to ReadCommandLine_CompareLocationData while bit 7 is present.
D8E8 JR NZ,ReadCommandLine_CompareLocationData
D8EA LD A,$08 Print character 08 through Print_Character.
D8EC CALL Print_Character
D8EF INC B Jump back to ReadCommandLine_CompareLocationData while this byte is not 22.
D8F0 DEC HL
D8F1 LD A,(HL)
D8F2 CP $22
D8F4 JR NZ,ReadCommandLine_CompareLocationData
D8F6 LD A,($D897) Toggle the quotation-mark flag at D897.
D8F9 XOR $01
D8FB LD ($D897),A
D8FE JR ReadCommandLine_CompareLocationData Read the next key from ReadCommandLine_CompareLocationData.
A quotation mark toggles the typing marker. A key at or above 40 is stored as typed.
ReadCommandLine_TestQuotationMarkToggles D900 CP $40 Jump ahead to ReadCommandLine_TestCountHasReached if the key is at least 40.
D902 JR NC,ReadCommandLine_TestCountHasReached
D904 CP $22 Jump ahead to ReadCommandLine_TestBlankFullStop unless the key is a double quote (22).
D906 JR NZ,ReadCommandLine_TestBlankFullStop
D908 LD A,($D897) Toggle the quotation-mark flag at D897.
D90B XOR $01
D90D LD ($D897),A
D910 CALL NZ,TestFullStop Call TestFullStop to add a full stop when the quotation marker turns on.
D913 LD A,$22 Take a quotation mark and jump ahead to ReadCommandLine_TestCountHasReached.
D915 JR ReadCommandLine_TestCountHasReached
A blank or a full stop ends this input, and a carriage return ends the line.
ReadCommandLine_TestBlankFullStop D917 CP $20 Jump to ReadCommandLine_TestCountHasReached if the player pressed "SPACE".
D919 JR Z,ReadCommandLine_TestCountHasReached
D91B CP $0D Jump to ReadCommandLine_CommandMarkerLeave if the player pressed "ENTER".
D91D JR Z,ReadCommandLine_CommandMarkerLeave
D91F CP $2E Jump ahead to ReadCommandLine_TestCountHasReached if the input is 2E.
D921 JR Z,ReadCommandLine_TestCountHasReached
D923 CP $2C Jump ahead to ReadCommandLine_TestCountHasReached if the input is 2C.
D925 JR Z,ReadCommandLine_TestCountHasReached
D927 CP $2F Jump ahead to ReadCommandLine_TestCountHasReached if the input is 2F.
D929 JR Z,ReadCommandLine_TestCountHasReached
D92B CP $60 Jump ahead to ReadCommandLine_TestCountHasReached if the input is 60.
D92D JR Z,ReadCommandLine_TestCountHasReached
D92F CP $2D Jump ahead to ReadCommandLine_TestCountHasReached if the input is 2D.
D931 JR Z,ReadCommandLine_TestCountHasReached
D933 CP $3A Go to ReadCommandLine_TestCountHasReached when the input is a colon.
D935 JR Z,ReadCommandLine_TestCountHasReached
D937 CALL TestDigit Call TestDigit and jump to ReadCommandLine_CompareLocationData if the character is not a digit.
D93A JR C,ReadCommandLine_CompareLocationData
ReadCommandLine_TestCountHasReached D93C DEC B Jump to ReadCommandLine_CommandLinePrints_0 if the count has reached zero.
D93D INC B
D93E JR Z,ReadCommandLine_CommandLinePrints_0
D940 LD (HL),A Store the character in the line buffer and print it through Print_Character.
D941 CALL Print_Character
D944 INC HL Step to the next entry and count down one.
D945 DEC B
ReadCommandLine_CommandLinePrints_0 D946 JP ReadCommandLine_CompareLocationData Return to ReadCommandLine_CompareLocationData for the next character of the command.
Read the command marker, then leave a carriage return.
ReadCommandLine_CommandMarkerLeave D949 LD A,($D897) Call LeaveQuoteResult if the quotation mark flag at D897 is zero.
D94C AND A
D94D CALL Z,LeaveQuoteResult
D950 CALL TestFullStop Call TestFullStop to test for a sentence stop.
D953 LD A,$0D Take a new line and store it at the line buffer, then call Print_Character to print character.
D955 LD (HL),A
D956 CALL Print_Character
D959 OR %00000001 Reset the zero flag.
D95B RET Return.
View the equivalent code in;
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