Home Computer Magazine’s Bug-Out

Title – Home Computer Magazine’s Bug-Out
System – Commodore 64
Author – Home Computer Magazine Staff
Publication – Home Computer Magazine, Volume 5, No. 6, November 1985
Page Scans – 1 2 3
Preserved by – eboy71
Recommended Emulator – VICE

Download ROM

Loading the Utility –

• Mount the disk image (BUG-OUT-HCM-Nov-85-Vol-5-06.d64) in your emulator. In VICE, this is done by selecting File → Attach Disk Image
• Load the app by typing LOAD”BUG-OUT”,8
• Once loaded, type RUN to start

Article Text

Bug-Out is an error detection program for catching type-in mistakes. It is available for every computer brand HCM covers— Apple, Atari, Commodore, IBM, and Texas Instruments. When you use this utility, typos are easily found and corrected.

Before you type-in another HCM program, type-in the Bug-Out program specified for your computer. Because a properly typed-in Bug-Out routine is essential for it to accurately detect typing errors in other programs, be extra careful to ensure accuracy. Once you have it entered, save Bug-Out to tape (an option for Atari and Commodore only) or disk.

Comparing Two Sets of BOC’s
When you look at our listings, you will notice an upper-case letter placed in the left-most column at the beginning of each program line. Separated from the line numbers by a bold vertical bar, this letter is the correct BOC. Do not type these letters in. The BOC is a quality control character. Each program line is carefully dissected, and mathematically compacted into a single character representation.

These letters will help you detect key-in errors after you have a listing fully entered. When you RUN the Bug-Out program as directed below, it will generate another series of BOCs either on the screen, or to a printer. Compare the codes generated by the Bug-Out program with the codes published in the left-most column of our listings. If a published BOC for a line is different from a BOC for your typed version of the same line, you will know that line contains a typing error.

How To Do It

1. The first step is to type-in the desired program.

2. After typing the program in, SAVE it as usual.

3. Then also SAVE the program as an ASCII text file— this is the format needed for Bug-Out to do its job. Always use a different file name to distinguish between the program file SAVEd in step 2 and this text file. We suggest you add a suffix like .T (or __T on the 99/4A) to the end of the text file name for added clarity. The process of saving programs as ASCII text files on each machine is detailed on page 78 (see “Turning Programs Into Text Files”).

4. After you’ve SAVEd your program as an ASCII text file, make sure that the disk or tape containing the text file is inserted, then RUN the Bug-Out program. Once RUN, Bug-Out will ask for the name of the ASCII file and whether you want the program’s output to go to the screen or the printer. After all this has been entered, the computer will print out its list of BOCs and the corresponding line number. For example:

N 100 S 110 Q 120 .. .

5. Carefully go through the program listing in the magazine to find, and take note of, all the published BOCs that are different from the BOCs generated by the Bug-Out program. Every line that you find with a different BOC code has been typed incorrectly, and should be carefully examined and corrected.

To correct your mistakes (if any), LOAD (OLD on the 99/4A) the program version (not the text file) that you keyed in previously. Now, make the necessary changes to the incorrect program lines and repeat the previous 5 steps until all the BOC codes match. Once they all match, your program should be error free.

REM statements that are not typed correctly will result in erroneous BOCs. If the only differences between a typed-in program and the magazine listing are in REM statements, the program will still RUN as intended. So you needn’t waste time concerning every REM statement before running your HCM programs.

Turning Programs into Text Files
C-64 disk users enter: OPEN 8,8,8,”PRGNAME.T,S,W” : CMD 8 : LIST

When the cursor returns, enter: PRINT# 8 : CLOSE 8

C-64 tape users enter OPEN 1, 1,1, “PRGNAME.T”: CMD 1: LIST

When the cursor returns, enter: PRINT#1 : CLOSE 1

Editor’s Notes:

• This is definitely one of the more novel types of automatic proofreaders (like COMPUTE!’s Automatic Proofreader) that were around in the 80’s.
• Most would check the program in real time. Home Computer Magazine took the approach of checking it after the program was typed in, which first involved converting the program to a text file (see the instructions above.)