DISASSEMBLING A PROGRAM

(READING THE .HEX FILE)
Page 4

This section does not use the Multi-Chip Programmer but it is in this section as it is a part of the process of programming. If you take a .hex program from a book or magazine, or read a program from a chip, the block of digits is almost impossible to read. Sometimes it is important to know if the numbers refer to a particular program and you may wish to know if it is the latest version. You may also need to make a modification.
The program in this article (the program is called Disasm) will take a .hex file from a PIC16F84 and convert it back into a layout very similar to the set of instructions in an .asm file. The only difference is the absence of annotations and labels.
The program is called Disasm (for Dis-assembly program) and the files you need to get this program up-and-running, are HERE.
The files are:

• Disasm.exe 15k Application File This is the file you use (see below).
• About.frm 3k FRM File
• Cmdialog.vbx 19k VBX File
• Disasm.frm 10k FRM File
• Disasm.mak 1k MAK File
• VBRUN300.DLL 389k DLL file
  These are on your computer, in Disassembler folder: _CD/_Pic Lab_cd/Disassembler

Disasm requires two files: Cmdialog.vbx and Vbrun300.dll to be put into: C:\Windows\System
Installation is now complete.

USING DISASM

Disasm will disassemble your .hex files. Firstly you will need a .hex file.
For all the .hex files for the 5x7 Display Project, [click HERE](//TODO FIXME - should link to github file repo).
To make it easy, you can put them onto a disk and access them in drive A as 84 Disasm only sees the first 8 letters of each name and it is very difficult to follow if the names have more than 8 letters.

You are now ready to use Disasm.
To access Disasm, click HERE.
To run Disasm, double-click on the icon:

and a window will appear.

Click on File. Click on Open. Double-click on the open folder: c:\ The folders on drive C will appear. Move down the list until 5x7dis~1 appears. Double-click on 5x7dis~1. The .hex files in this folder will appear in the window. Double-click on the file you want to disassemble. It will disassemble immediately. You can open two or more .hex windows (Disasm windows) at the same time to compare listings.
To save a disassembled file you MUST rename the extension to .asm, otherwise you will LOSE the original .hex listing.
To save a file, click on File. Click on Save as: Click on the highlighted file in the address window to de-highlight it. Change the extension to .asm Click ok.
If you are working on a project, you must keep a back-up copy of your program on a floppy, just in case something goes wrong. It is very difficult to re-build something that is lost, especially if it is a written piece of work.