Professional BASIC Programming Tips

Techniques used by expert Commodore programmers to write faster, more efficient code.

Speed Optimization

REM SLOW:
FOR I = 1 TO 1000
X = X + 1
NEXT I

REM FAST (USE INTEGER VARIABLES):
FOR I% = 1 TO 1000
X% = X% + 1
NEXT I%

Memory-Saving Tricks

• Remove REM statements in final version
• Use multiple statements per line with colons
• Shorten variable names (A instead of ANSWER)
• Use ? instead of PRINT

REM EXPANDED (EASY TO READ):
10 REM CALCULATE TOTAL
20 LET TOTAL = 0
30 FOR COUNT = 1 TO 10
40 LET TOTAL = TOTAL + COUNT
50 NEXT COUNT
60 PRINT "TOTAL IS "; TOTAL

REM COMPRESSED (SAVES MEMORY):
10 T=0:FORI=1TO10:T=T+I:NEXT:?"TOTAL IS";T

Useful Subroutines

59000 REM *** CLEAR SCREEN ***
59010 PRINT CHR$(147);:RETURN

59100 REM *** WAIT FOR KEYPRESS ***
59110 GET A$:IF A$="" THEN 59110
59120 RETURN

59200 REM *** CENTER TEXT ***
59210 PRINT TAB((40-LEN(T$))/2);T$
59220 RETURN

Debugging Technique

10 REM ADD STOP POINTS TO DEBUG
20 X = 5: Y = 10
30 STOP : REM PROGRAM PAUSES HERE
40 Z = X * Y
50 PRINT Z
RUN
BREAK IN 30
PRINT X, Y    : REM CHECK VALUES
CONT          : REM CONTINUE RUNNING

"The best programmers are lazy - they write efficient code so the computer does more work and they do less!" - COMPUTE! Magazine