7  REM  PSQUAR, HEWLETT-PACKARD 36249A, 6/74
8  REM  DEF FNA(X)=M*X+B
10  REM PROGRAM PATTERN SQUARES
12  REM JOHN A. COCHRAN R.H.S. RIDGEFIELD 12/27/72
15  DEF FNA()=M*+B
50  REM CHANGE EQUATION AT STATEMENT 300
70  LET T=0
200  PRINT "INPUT VALUES FOR LEFT,RIGHT,BOTTOM,AND TOP OF GRAPH:"
210  INPUT X5,X6,Y5,Y6
280  PRINT "PLTL"
282  LET M=-1
285  FOR B=-15 TO 15 STEP 5
287  READ N5,M5,S5
290  FOR X=N5 TO M5 STEP S5
300  LET Y=FNA(X)
305  GOSUB 9500
310  NEXT X
315  LET T=0
320  PRINT "       PLTT"
322  PRINT "PLTL"
325  NEXT B
330  LET M=0
335  FOR B=-10 TO 10 STEP 2.5
340  READ N5,M5,S5
345  FOR X=N5 TO M5 STEP S5
350  LET Y=FNA(X)
355  GOSUB 9500
360  NEXT X
365  LET T=0
367  PRINT "       PLTT"
370  PRINT "PLTL"
375  NEXT B
380  LET M=1
385  FOR B=-15 TO 15 STEP 5
387  READ N5,M5,S5
388  FOR X=N5 TO M5 STEP S5
390  LET Y=FNA(X)
392  GOSUB 9500
394  NEXT X
396  LET T=0
397  PRINT "       PLTT"
398  PRINT "PLTL"
400  NEXT B
405  FOR B=-10 TO 10 STEP 2.5
410  READ N5,M5,S5
415  FOR Y=N5 TO M5 STEP S5
420  LET X=B
425  GOSUB 9500
430  NEXT Y
435  LET T=0
437  PRINT "       PLTT"
440  PRINT "PLTL"
445  NEXT B
890  PRINT "       PLTT"
900  STOP 
9010  DATA -10,-5,1,-10,0,2,-10,5,1
9015  DATA -10,10,2,-5,10,1,0,10,2
9020  DATA 5,10,1
9025  DATA -10,10,2,-7.5,7.5,2.5,-5,5,2
9030  DATA -2.5,2.5,2.5,-10,10,5,-2.5,2.5,2.5
9035  DATA -5,5,2,-7.5,7.5,2.5,-10,10,5
9040  DATA 5,10,1,0,10,2,-5,10,3
9045  DATA -10,10,2,-10,5,3,-10,0,2
9050  DATA -10,-5,1
9055  DATA -10,10,5,-7.5,7.5,2.5,-5,5,2
9060  DATA -2.5,2.5,2.5,-10,10,5,-2.5,2.5,2.5
9065  DATA -5,5,2,-7.5,7.5,2.5,-10,10,5
9500  LET X8=9999*(X-X5)/(X6-X5)
9510  LET Y8=9999*(Y-Y5)/(Y6-Y5)
9520  IF X8>9999 OR Y8>9999 THEN 9600
9530  IF X8<0 OR Y8<0 THEN 9600
9540  IF T=0 THEN 9700
9550  PRINT "PLTL"
9560  LET T=0
9570  GOTO 9700
9600  IF T=1 THEN 9800
9610  PRINT "       PLTT"
9620  PRINT "OFF SCALE"
9630  LET T=1
9640  GOTO 9800
9700  PRINT INT(X8);INT(Y8)
9800  RETURN 
9999  END 
