Using Debug to create COM programs from .SCR files

The article mentions a number of script files (.SCR files) used with Debug to create .COM files. The process of creating these files is as follows:

  1. 1. Open up Memo and key in the files exactly as they are shown in the article, with one exception. The text that comes after the semicolon on each line of a script file is simply a remark describing what the line does. You may omit typing the semicolon and text that follows when you key in the script file. Any line with only a semicolon and text should be completely omitted.

  2. Be aware also that each script file listing will have two blank lines only: one between the INT 21 and RCX statements, and one after the final Q command.

  3. 2. After you have keyed in the lines, double-check your typing and then save the file with its given Filename (i.e., in example 1, the file would be saved as YN.SCR).

  4. 3. Assemble the script file by going to the DOS prompt and entering the command: debug < filename.scr where FileName stands for the name of the script file.

  5. 4. (Optional) Triple-check your work, from the DOS prompt use the command: debug filename.com and, at DEBUG's - prompt, press U, and then (ENTER), to unassemble the code. Compare the unassembled listing on the screen with the one given here. If needed, correct any typing mistakes and try again.

Creating batch files

Most batch files described in this article can be created in Memo (or any word processor capable of saving a file in ASCII format).

Open Memo and key in the batch files as shown below. Then save the file under the name given. It's that simple.

Inserting binary code into a batch file, as described in this article, cannot be done in Memo. You'll need a text editor capable of displaying binary code. QEDIT <See Shareware/Freeware index> is one such text editor. There are others.