'EDIT THE MouseLimits VALUES TO:
CALL MouseLimits(6, 24, 2, 18, 6, 6) 
'REPLACE ALL THE SUBROUTINES WITH: 
OpeningScreen: COLOR 0, 3: CLS
  OPEN "MATHCODE.TXT" FOR INPUT AS #1: i = 1             'Display Puzzle
    DO: i = i + 1: LOCATE i, 6: LINE INPUT #1, tmp$: PRINT tmp$
    LOOP UNTIL EOF(1) OR i = 17
    LOCATE 1, 1: COLOR 1: FOR i = 1 TO 17: PRINT i: NEXT i
    LOCATE 1, 26: PRINT "LeftDrag PUZZLE LETTER or SPACE to row2"
    LOCATE , 26: PRINT "<< SingleLeftClick LETTER HERE"
    LOCATE , 26: PRINT "<< SingleRightClick HERE to renew data"
    LOCATE , 26: PRINT "<< SingleLeftClick NUMBER HERE"
    LOCATE , 26: PRINT "RightDrag row 10, 13 or 16 to below AND"
    LOCATE , 26: PRINT "OPTIONAL type text "; CHR$(27); " "; CHR$(26);
    PRINT ", MUST PressEnter"
    LOCATE 19, 2: PRINT "DoubleLeftClick to check result"
    PRINT " DoubleRightClick OR Esc to close program"
    PRINT " Press Alt+Enter To switch between screens"
  CLOSE #1: COLOR 15
RETURN 
SingleClick: GOSUB RowCol          'Start Here With presses=1 releases=1
  IF click = 1 AND col <= 24 AND (row = 2 OR row = 4) THEN 'click=1=Left
    letter$ = CHR$(SCREEN(2, col)): number$ = CHR$(SCREEN(4, col))
    IF letter$ < "A" OR letter$ > "Z" THEN RETURN
    FOR i = 6 TO 17: FOR j = 6 TO 22 STEP 2: LOCATE i, j
      IF row = 2 THEN                      'Replace Letters With Numbers
        IF CHR$(SCREEN(i, j)) = letter$ THEN PRINT number$;
      ELSEIF row = 4 THEN                  'Replace Numbers With Letters
        IF CHR$(SCREEN(i, j)) = number$ THEN PRINT letter$;
      END IF
    NEXT j: NEXT i: IF row = 4 THEN LOCATE 2, col: PRINT " ";
  END IF
  IF click = 2 AND row = 3 THEN GOSUB OpeningScreen       'click=2=Right
RETURN 
DoubleClick: GOSUB RowCol          'Start Here With presses=2 releases=2
  IF click = 1 THEN                                     'DoubleLeftClick
    x$ = "Yes": y$ = ""                       'x$=Yes=All Digits In Row8
    FOR i = 6 TO 22 STEP 2: z$ = CHR$(SCREEN(8, i)): y$ = y$ + z$
      IF z$ < "0" OR z$ > "9" THEN x$ = "No"       'x$=No=Not All Digits
    NEXT i: LOCATE 23, 4: IF x$ = "No" THEN PRINT "No ! ROW 8 = "; y$
    IF x$ = "Yes" THEN                                 'Calculate Result
      denominator& = VAL(LEFT$(y$, 3)): numerator& = VAL(RIGHT$(y$, 6))
      LOCATE 23, 4: PRINT numerator&; CHR$(246); denominator&;
      PRINT "  quotient"; " ="; numerator& \ denominator&;
      PRINT " remainder"; " ="; numerator& MOD denominator&;
    END IF
  END IF
  IF click = 2 THEN press$ = CHR$(27)   'DoubleRightClick Closes Program
RETURN 
DragMouseCursor: GOSUB RowCol      'Start Here With presses=1 releases=0
  i = row: j = col: tmp$ = CHR$(SCREEN(i, j))     'Save At Start Of Drag
  LOCATE , , 1, 0, 7: CALL AssemblyCode(1, 0, 0, 0)   'Show Both Cursors
  WHILE releases < 1                      'Wait For Mouse Button Release
    CALL AssemblyCode(3, 0, cx, dx): GOSUB RowCol         'Get row & col
    IF click = 1 THEN row = 2 ELSE IF click = 2 THEN col = 29   'Targets
    LOCATE row, col                 'Text Cursor Shows Position For Drop
    bx = click - 1: CALL AssemblyCode(6, bx, 0, 0): releases = bx
  WEND                    'Exit Loop When Button Released At End Of Drag
  LOCATE , , 0: CALL AssemblyCode(2, 0, 0, 0)         'Hide Both Cursors
  IF click = 1 THEN                                           'Left Drop
    IF tmp$ = " " OR (tmp$ >= "A" AND tmp$ <= "Z") THEN PRINT tmp$;
  ELSEIF click = 2 THEN                                      'Right Drop
    IF tmp$ = " " THEN col = 26: GOSUB TypeMessage           'Drag Blank
    IF tmp$ = CHR$(196) AND (i = 10 OR i = 13 OR i = 16) THEN  'Drag Eqn
      x$ = CHR$(SCREEN(i - 2, j)): IF x$ = " " THEN x$ = "0" 'Characters
      y$ = CHR$(SCREEN(i - 1, j)): IF y$ = " " THEN y$ = "0" 'Of Dragged
      z$ = CHR$(SCREEN(i + 1, j)): IF z$ = " " THEN z$ = "0"   'Equation
      IF z$ = "0" AND x$ <> y$ THEN y$ = y$ + "-1" ELSE y$ = y$ + "  "
      PRINT x$; "-"; y$; "="; z$                 'Print Dragged Equation
      j = j - 10: IF i > 10 THEN j = j - 2: IF i > 13 THEN j = j - 2
      LOCATE row, 51: PRINT "Row"; i; ", Eqn"; j / 2; 'Row & Eqn Numbers
      col = 38: GOSUB TypeMessage     'In Same Row As Eqn To Type Result
    END IF
  END IF
RETURN 
TypeMessage: LOCATE , , 1, 0, 7                        'Show Text Cursor
  DO: LOCATE , col  'Text Cursor At Position For Character To Be Printed
    DO: press$ = INKEY$: LOOP UNTIL press$ <> ""     'Wait For Key Press
    IF press$ >= " " THEN PRINT press$; : col = col + 1   'Key=Character
    IF press$ = CHR$(0) + "K" THEN col = col - 1         'Key=Left Arrow
    IF press$ = CHR$(0) + "M" THEN col = col + 1        'Key=Right Arrow
    IF col < 26 THEN col = 26 ELSE IF col > 64 THEN col = 64 'col Limits
  LOOP UNTIL press$ = CHR$(13): LOCATE , , 0    'Exit & Hide Text Cursor
RETURN 
RowCol:
  row = dx \ 8 + 1: col = ((cx \ 8 + 2) \ 2) * 2       'col=Even Numbers
RETURN 
'LEAVE THE SUBPROGRAMS UNCHANGED						         o