In Notepad open an EXE file (such as a compiled C program). What happens?

### A good answer might be:

There many bit patterns the monitor can't handle; the display is messed up.

# Executable Files

For extra fun, try sending an EXE file to a printer. Make sure you can stop the printer if you need to. Sometimes it will print endless sheets of paper covered with gibberish. When one says "executable file" one really means:

> Executable File: A file containing a sequence of bytes. Each byte holds a bit pattern that represents part of a machine instruction for a particular processor. The operating system can load (copy) an executable file into main storage and can then execute the program.

A byte in an executable file can contain any possible 8-bit pattern. A file like this often is called a Binary File. This is misleading vocabulary. All files represent their information as binary patterns. When one says "MS Word file" one really means:

> Word File: A file containing a sequence of bytes holding bit patterns created by the MS Word program, which are understood only by that program (and a few others).

There is nothing special about the various "types" of files. Each is a sequence of bytes. Each byte holds a bit pattern. A byte can hold one of 256 possible patterns (although some file types allow only 128 or fewer of these patterns). When longer bit patterns are needed they are held in several contiguous bytes.

### QUESTION 8:

Say that you want to compress a text file with a file compression utility like WinZip. About what percent compression can you expect? (Hint: if you have been paying attention, you can figure out this answer).