Basic Renumber

 9949 LET g=PEEK 23635+PEEK 23636*256
 9950 LET l=PEEK g*256+PEEK (g+1): LET g=g+4
 9951 PRINT AT PI,4-LEN STR$ l;l;
 9952 IF PEEK g=14 THEN LET g=g+6
 9953 IF PEEK g=13 THEN LET l=0
 9954 PRINT CHR$ PEEK g;: LET g=g+1
 9955 IF l THEN GO TO 9952
 9956 PAUSE 0: CLS : GO TO 9950
 9957 LET bs=26710: REM RENUM STARTS HERE 
 9958 INPUT " INPUT start no. ";g: INPUT " THEN INPUT STEP ";ff
 9959 LET m=g: CLS 
 9960 PRINT "Change these lines": LET i=bs+4
 9961 IF PEEK i<>13 THEN GO TO 9965
 9962 IF PEEK (i+1)>34 THEN GO TO 9990
 9963 LET m=m+ff
 9964 LET i=i+5
 9965 LET h=(1 AND PEEK i=236)+(2 AND PEEK i=237)
 9966 IF PEEK i=14 THEN LET i=i+5
 9967 IF h THEN GO SUB 9969
 9968 LET i=i+1: GO TO 9961
 9969 PRINT m;(" GO TO " AND h=1)+(" GO SUB " AND h=2);
 9970 LET h=0
 9971 IF PEEK (i+1)>=48 AND PEEK (i+1)<58 THEN GO TO 9973
 9972 PRINT " * ": RETURN 
 9973 LET j=2
 9974 IF PEEK (i+j)=14 THEN GO TO 9978
 9975 LET j=j+1
 9976 IF j>5 THEN GO TO 9972
 9977 GO TO 9974
 9978 LET l=1: LET k=0
 9979 LET k=k+(PEEK (i+j-1)-48)*l
 9980 LET j=j-1
 9981 IF PEEK (i+j-1)=236 OR PEEK (i+j-1)=237 THEN GO TO 9983
 9982 LET l=l*10: GO TO 9979
 9983 LET j=bs: LET n=0
 9984 IF PEEK j*256+PEEK (j+1)>=k THEN GO TO 9988
 9985 LET n=n+1
 9986 LET j=j+(PEEK (j+2)+PEEK (j+3)*256)+4
 9987 GO TO 9984
 9988 LET k=g+n*ff
 9989 PRINT k: RETURN 
 9990 LET j=0: LET i=bs
 9991 GO SUB 9994
 9992 LET i=i+PEEK (i+2)+PEEK (i+3)*256+4
 9993 GO TO 9991
 9994 IF PEEK i>34 THEN STOP 
 9995 IF g<256 THEN GO TO 9997
 9996 LET j=j+1: LET g=g-256
 9997 POKE i,j: POKE (i+1),g
 9998 LET g=g+ff: RETURN 
 9999 SAVE "BASRENUM"