File comparisons

When practising the tutorials it is worth using a Ramdisk. For further details of a ramdisk go here

I have files on my computer system which carry legal significance.  I have backed up my files to another directory or have downloaded a file and want to check if anything has changed.  Very large files can have a password placed in them.  Comparing two large files can enable a password to be found.





Create Files as instructions here.


1 Compare Files


--------------NetWork-----------------

1 Two Files Compares two files

2 Two Files Byte Differences 10K to 1000k max Compares two files and checks for differences

3 One File with Many Select file and search for other files that are exact copies of this file

4 File with Compressed File Compares compressed File and non-compressed file
There are three types of compressed Files
  • Compression of Small file
  • Compression of Large File
  • Compression of Large File that is split into Manageable  chunks for sending via email
All three types of compressed file can be compared with a single file.  The compression routine was written at the time of Windows98.  It was designed for files less than 4.2GB and was at a time when you had to find a compression program.  So the compression was useful as part of this program.

5 Partial Files Compares two files for a set load of bytes.  The position where the compare starts can be different for each file.

-No NetWork Encrypted File Compare-

---Single Password----

6 Decrypt

7 Split Decrypt

---Two Passwords---

8 Decrypt

9 Split Decrypt



Test Files


  1. Download "c.t" and "d.t"
  2. Move both "c.t" and "d.t" to directory on ramdisk called "large"
  3. Create " create SHA Check Files (19,929,168 Bytes)" using the "Install - New Create Files , Directories for Program Checking"
  4. Run another program instance
  5. Type "ALT+U"
  6. Type "I"

  1. Click on "create SHA Check Files (19,929,168 Bytes) in list (A)
  2. Click on "Get Directory" button
  3. Select Drive
  4. Create Directory "check"
  5. Select Directory "check


  1. Type "ALT+3"


  1. Click on "Create Selection" button (E)
    1. SHA Check Files created in Folder
    2. SHA Check Files created in Sub Folder


  1. Click on "Leave" button (C)
  2. Close Program Instance


  1. Copy file "a.txt" from "check" directory to directory above "check" directory
    1. Will use this in 3 One File with Many










 Two Files


  • By Mouse
  1. Click on "File Comparisons"
  2. Click on "Compere Files"
  3. Click on "1 Two Files"
  •       By Keyboard
  1. Type "ALT+F"
  2. Type "11"
  3. Select directory "large"

  1. Select file "c.t"
  2. Type "ALT+1" or click on "File -1" button
    1. File "c.t" selected
  3. Select file "d.t"
  4. Type "ALT+2" or click on "File -2" button
    1. File "d.t" selected


  1. Type "ALT+3" or click on "Process -3" button
    1. Two files are checked byte by byte
    2. In this case found to be different


  1. Type "ALT+O" or click on "OK" button
    1. Display returns to Opening Screen
2 Two Files Byte Differences 10K to 1000k max


  •   By Mouse
  1. Click on "File Comparisonss"
  2. Click on "Compare Files"
  3. Click on "1 Two Files"
  • By Keyboard
  1. Type "ALT+F"
  2. Type "12"
  3. Select directory "large"


  1. Select file "c.t"
  2. Type "ALT+1" or click on "File -1" button
    1. File "c.t" selected

  1. Select file "d.t"
  2. Type "ALT+2" or click on "File -2" button
    1. File "d.t" selected

(A) Directory of first file
(B) First file name
(C) Directory of Second file
(D) Second file name
(E) Size of data to check list
(F) Where to start data checking list in 10 k steps from 0K to 490K. k in killo bytes
(G) Where to start data checking list in 0.5M steps from 0M 0.5M before end of file. N in Mega bytes
(H) Copies selected parameters onto clipboard
(I) clear clipboard
(J) continue to file compare with start point in (O)
(K) Return to opening screen
(L) Number of different bytes that can be recorded when making comparisons
(M) Number of bytes that cannot be recorded if different
(N) File size
(O) Position where file comparisons start
(P) start pint from list (F)
(Q) start point from list (G)
(R) Bytes that can be assessed

  1. Click on "1000k" in list (E)
    1. 1,000,000 is entered in (L)
  2. Click on "10k" in list (F)
    1. 10,000 is entered in (P)
    2. 10,000 is entered in (O)
    3. 1,038,576 is entered in (R)
  3. Click on "0.5M" in list (G)
    1. 510,000 is entered in (O)
    2. 500,000 is entered in (Q)
    3. 538,576 is entered in (R)
  4. Click on "Copy to ClipBoard" button (H)




  • Clipboard contents pasted into notepad


  1. Type "ALT+C" or click on "Continue" button (J)
    1. Two files in (B) and (D) compared from start point (O)


  1. Click on "Copy Selected Line" button (D)

  • Clipboard contents pasted into notepad

  1. Click on "Copy All" button (E)

  • Clipboard contents pasted into notepad



  1. Click on "Copy All tabbed" button (J)

  • Clipboard contents pasted into notepad



  • Clipboard contents pasted into OpenOffice Calc program




  1. Click on "Copy 4 lines" button (I)

  • Clipboard contents pasted into notepad

  1. Click on "Go Again" button (K)
    1. Returns to Display below
  1. Click on "Leave" button (G)
    1. returns to opening screen


  1. Click on "Leave" button (G)
    1. returns to opening screen

3 One File with Many


  1. Copy file "a.txt" from directory "check" to directory above "check"
    1. Will use this file in tutorial that follows
  • By Mouse
  1.     Click on "File comparisons"
  2.     Click on "Compare Files"
  3.     Click on "3 One File with Many"
  • By Keyboard
  1.     Type "ALT+F"
  2.     Type "13"


  1. Select file "a.txt"
  2. Type "ALT+1" or click on "File -1" button
  3. File "a.txt" selected
  4. Type "ALT+2" or click on "File -2" button
  5. Directory selected


  1. Type "ALT+3" or click on "Process -3" button


  • This is done on a ramdisk. Hence the speed of 0ms
  • Found two files that were the same as search file "G:\a.txt"
  1. Click on "Copy to ClipBoard" button
  2. Paste into notepad
  • Can click on "Print" button to print results


  1. Close notepad
  2. Click on "leave" button
    1. Display returns to opening screen

4 File with Compressed File

The  tutorial to create compressed file "testfile.txt" is Here.  "testfile.txt" is used because "testfile.txt" is small enough for small compression and large enough for large compression and split file compression.
The tutorial can be used to create:
  • "testfile.txt.ezp" size 102,600 from "testfile.txt" size 2,228,890
  • "testfile.txt.elzp" size 102,606 from "testfile.txt" size 2,228,890
  • "testfile.txt.0lezp" split file compression from "testfile.txt" size 2,228,890 with sizes
    • testfile.txt.0lezp - 194
    • testfile.txt.1lezp - 46,489
    • testfile.txt.2lezp - 45,937
    • testfile.txt.3lezp - 10,676

  1. Make directory "compress"
  2. Copy to "compress" files:
    1. "testfile.txt"
    2. "testfile.txt.ezp"
    3. "testfile.txt.elzp"
    4. "testfile.txt.0lezp"
    5. "testfile.txt.1lezp"
    6. "testfile.txt.2lezp"
    7. "testfile.txt.3lezp"


  •     By Mouse
  1.  Click on "File Comparisons"
  2. Click on "Compare Files"
  3. Click on "4 File with Compressed File"
  • By Keyboard
  1. Type "ALT+F"
  2. Type "14"
  3. Select directory "compress"


  1. Select "testfile.txt.ezp"
  2. type "ALT+1"
    1. "testfile.txt.ezp" selected
  3. Select "testfile.txt"
  4. type "ALT+2"
    1. "testfile.txt" selected


  1. Type "ALT+3"


  1. Click on "Leave" button
    1. display returns to opening screen
  1. Type "ALT+F"
  2. Type "14"
  3. Select directory "compress"

  1. Select "testfile.txt.elzp"
  2. type "ALT+1"
    1. "testfile.txt.elzp" selected
  3. Select "testfile.txt"
  4. type "ALT+2"
    1. "testfile.txt" selected


  1. Type "ALT+3"


  1. Click on "Leave" button
    1. display returns to opening screen
  1. Type "ALT+F"
  2. Type "14"
  3. Select directory "compress"

  1. Select "testfile.txt.0lezp"
  2. type "ALT+1"
    1. "testfile.txt.0lezp" selected
  3. Select "testfile.txt"
  4. type "ALT+2"
    1. "testfile.txt" selected


  1. Type "ALT+3"




  1. Type "ALT+3"


5 Partial Files

very large file example on network



  • By Mouse
  1. Click on "File Comparisons"
  2. Click on "Compare Files"
  3. Click on "5 Partial Files"
  • By Keyboard
  1. Type "ALT+F"
  2. Type "15"
  3. Select directory "\\VBOXSVR\test"
    1. (on my system)
  4. Using truecrypt made 19GB file "a.t"
    1. made copy of "a.t" called "a (copy).t"
  5. select "a (copy).t"
  6. Type "ALT+1" or click on "File -1" button
    1. "a (copy).t" selected
  7. Select "a.t
  8. Type "ALT+2" or click on "File -1" button
    1. "a.t" selected


  1. Type "ALT+3" or click on "Process -3" button

(A) Hexidecimal number
(B) Hexidecimal number converted to decimal
(C) Number of characters of hexidecimal number in (A)
(D) "OK" button press to start file compare
(E) "Cancel" press to return to opening screen
(F) Number of bytes to compare
(G) Size of file 1
(H) Position where compare starts for File 1
(I) file 1 "size" (G) minus "Number of bytes to compare" (F)
(J) Position of last compare byte for File 1
(K) File 1 name here it is on a network
(L) Size of File 2
(M) Position where compare starts for File 2
(N) File 2 "size" (L) minus "Number of bytes to compare" (F)
(O) Position of last compare byte for File 2
(P) File 2 name here it is on a network

  1. Copy Size in (I) to (F)
    1. 20,401,084,656 in (I) is displayed in (F)
  2. Enter 10 in (H)
  3. Enter 10 in (M)


  1. Click on "OK" button (D)
    1. Compare file 1 and file 2 byte by byte commences


  • Display when bytes in the two files are being compared


  • Display when All bytes have been compared
  • Click on "Leave" button to return to opening screen
  • Click on "Copy to ClipBoard" button to copy details to clipboard
  • Click on "Clear ClipBoard" button to clear clipboard
  • Click on "Go Again" button to return to "Partial Compare Details" screen
  1. Click on "Copy to ClipBoard" button
  2. Paste Clipboard into notepad


  1. Close Notepad
  2. Click on "Go Again" button
File a.t was modified with 1 Byte changed at position "20,400,992,257"
This modification was carried out using "6 Read File Sectors" (Modify Contents) under "Obtain Selected Data" in "Utilities" Type "ALT+U" then "O6"

  1. Put 10 in (H)
  2. Put 10 in (M)
  3. Put 20,401,094,646 in (F)

  1. Click on "OK" button (D)
    1. Compare file 1 and file 2 byte by byte commences


  • Compare starts at 10
  • File 1 different to file 2 at 20,400,992,257 Bytes
  • File 2 different to file 1 at 20,400,992,257 Bytes
  • Compared 20,400,992,247 bytes before difference found





  1. Click on "Cancel" button (E)
    1. Display returns to opening screen
5 Partial Files
2 Downloaded file example

  • By Mouse
  1. Click on "File Comparisons"
  2. Click on "Compare Files"
  3. Click on "5 Partial Files"
  • By Keyboard
  1. Type "ALT+F"
  2. Type "15"
  3. Select directory "large" that was prepared in test files
  4. Select "c.t"
  5. Type "ALT+1" or click on "File -1" button
    1. "c.t" selected
  6. Select "d.t"
  7. Type "ALT+2" or click on File -2" button
    1. "d.t" selected


  1. Type "ALT+3" or click on "Process -3" button


(A) Hexidecimal number
(B) Hexidecimal number converted to decimal
(C) Number of characters of hexidecimal number in (A)
(D) "OK" button press to start file compare
(E) "Cancel" press to return to opening screen
(F) Number of bytes to compare
(G) Size of file 1
(H) Position where compare starts for File 1
(I) file 1 "size" (G) minus "Number of bytes to compare" (F)
(J) Position of last compare byte for File 1
(K) File 1 name here it is on a network
(L) Size of File 2
(M) Position where compare starts for File 2
(N) File 2 "size" (L) minus "Number of bytes to compare" (F)
(O) Position of last compare byte for File 2
(P) File 2 name here it is on a network

  1. Type 1000000 in (F)
  2. Type 100 in (H)
    1. 1,000,100 entered in (J)
  3. Type 100 in (M)
    1. 1,000,100 entered in (OJ)


  1. Click on "OK" button


  1. Click on "Leave" button to return to opening screen