Title : The New Automatic Proofreader
System: Commodore 64
Author: Philip I. Nelson 
Publication: COMPUTE! and COMPUTE!’s Gazette, from February, 1986 onward. These particular scans were taken from the October, 1989 issue.
Page Scan: 74
Preserved By: Bryon Thur [eboy71]
Recommended Emulator: VICE [https://vice-emu.sourceforge.io/]


Loading the application:
* Mount the disk image (Compute New Automatic Proofreader.d64) in your emulator. In VICE, this is done by selecting File → Attach Disk Image
* Load the app by typing LOAD”NEW PROOFREADER”,8
* Once loaded, type RUN to start


Details:
* The New Automatic Proofreader is a utility for improving your accuracy when typing in programs from COMPUTE! and COMPUTE!’s Gazette
* It is a small program that resides in memory while you are typing your program. After typing each line, a 2-digit checksum is displayed in the top left corner of the screen. If it corresponds to the checksum printed in the issue, your line is correct.
* The first version (the Automatic Proofreader) was initially published in the October, 1983 issue of COMPUTE!’s Gazette
* This is the second major version and was initially published in the February, 1986 issue of COMPUTE!’s Gazette. Major improvements included in this version include:
   * Universal compatibility for all Commodore platforms (VIC, C64, C128, Plus/4, C16)
   * Advanced checksum for increased accuracy
   * Hexadecimal checksum (instead of decimal)


Article Text:
“The Automatic Proofreader’ helps you type in program listings for the 128, 64, Plus/4, and 16 and prevents nearly every kind of typing mistake.


Type in the Proofreader exactly as listed, Since the program can’t check itself, type carefully to avoid mistakes. Don’t omit any lines, even if they contain unfamiliar commands. After finishing, save a copy or two on disk or tape before running it. This is important because the Proofreader erases the BASIC portion of itself when you run it, leaving only the machine language portion in memory,


Next, type RUN and press RETURN. After announcing which computer it’s running on, the Proofreader displays the message ‘Proofreader Active”. Now you're ready to type in a BASIC program.


Every time you finish typing a line and press RETURN, the Proofreader displays a two-letter checksum in the upper-left corner of the screen. Compare this result with the two-letter checksum printed to the left of the line in the program listing. If the letters match, it’s almost certain the line was typed correctly. If the letters don’t match, check for your mistake and correct the line.


The Proofreader ignores spaces not enclosed in quotes, so you can omit or add spaces between keywords and still see a matching checksum. However, since spaces inside quotes are almost always significant, the Proofreader pays attention to them. For example, 10 PRINT“ THIS IS BASIC” will generate a different checksum than 10 PRINT”THIS ISBA SIC”.


A common typing error is transposition—typing two successive characters in the wrong order, like PIRNT instead of PRINT or 64378 instead of 64738. The Proofreader is sensitive to the position of each character within the line and thus catches transposition errors.


The Proofreader does not accept keyword abbreviations (for example, ? instead of PRINT). If you prefer to use abbreviations, you can still check the line by LISTing it after typing it in, moving the cursor back to the line, and pressing RETURN. LISTing the line substitutes the full keyword for the abbreviation and allows the Proofreader to work properly. The same technique works for rechecking programs you've already typed in.


If you're using the Proofreader on the Commodore 128, Plus/4, or 16, do not perform any GRAPHIC commands while the Proofreader is active. When you perform a command like GRAPHIC 1, the computer moves everything at the start of BASIC program space—including the Proofreader—to another memory area, causing the Proofreader to crash. The same thing happens if you run any program with a GRAPHIC command while the Proofreader is in memory.


Though the Proofreader doesn’t interfere with other BASIC operations, it's a good idea to disable it before running another program. However, the Proofreader is purposely difficult to dislodge: It’s not affected by tape or disk operations, or by pressing RUN/ STOP- RESTORE. The simplest way to disable it is to turn the computer off then on. A gentler method is to SYS to the computer's built-in reset routine (SYS 65341 for the 128, 64738 for the 64, and 65526 for the Plus/4 and 16). These reset routines erase any program in memory, so be sure to save the program you're typing in before entering the SYS command.


If you own a Commodore 64, you may already have wondered whether the Proofreader works with other programming utilities like “MetaBASIC.” The answer is generally yes, if you're using a 64 and activate the Proofreader after installing the other utility. For example, first load and activate MetaBASIC, then load and run the Proofreader,


When using the Proofreader with another utility, you should disable both programs before running a BASIC program. While the Proofreader seems unaffected by most utilities, there’s no way to promise that it will work with any and every combination of utilities you might want to use. The more utilities activated, the more fragile the system becomes.