CloneSpy by Thomas Jentzsch (Version 1.1)

In the year 2000 Thomas Jentzsch (XYPE) posted a small program, which he called "CloneSpy". Noticed by only a few people, this cute litte piece of software got lost, but now we have it here on GameReset!

It is a Borland Pascal program that compares rom-dumps. This is done by a pseudo dictionary-based compression, which finds duplicate code or data fields. Each rom is compared against all other ones, and when it shows some relationship to another rom, the later is also compared against the first. This gives two compare values, which are written into a text file ("clones.txt").

The following interesting facts can be read from this list:

  • which original rom was used for a clone/hack?
  • were has code been reused for different games
  • how big are the differences between PAL and NTSC versions?
  • how different are versions of the same game?
  • are all clone-suspected games really clones?
  • does an oversized dump also contain another rom?

Not included are

  • Homebrew-Demos (mainly from the Stella Mailing List),
  • Multipacks
    (because everythinng would be related to everything else :-),
  • splitted files of the Starpath-games,
  • all those "known bad dumps" (those with [b] in the name)

Thomas created an updated version 1.1 which is now ready to download!
It includes for example binaries like Lord of the Rings, Ewok Adventure, Elevator Action and it compares all known homebrew and demo-games in a second file ("Demos.txt").

Download and store them in one directory
To view Thomas' list created now on a base of 1399 bins, just start "ListSpy.exe"

ListSpy.exe shows the txt-file "clones.txt" as a list of matrixes, where similar roms are grouped together. The colored ( numbers show how similar two roms are.
(Red = very similar - Blue = little similar)
To create your own list based on your Atari 2600 binaries, put CloneSpy.exe in your bin-directory and run it.
Wait for a clones.txt-file to be created (it could be a long time!) and view this file with ListSpy.exe

Here is the download of version 1.1: (80 KB)
It contains:

  • CloneSpy.exe (the creator)
  • ListSpy.exe (the viewer)
  • Clones.txt (the list)
  • Demos.txt (textfile comparing homebrew and newer games)
    (Note: to read this file you have to rename it "clones.txt")

Here are some nice interesting points that become obvious reading the list:

  • Combat - Tank Plus inkludes Space War !
    (you could play it if you split the file)
  • there are two very different versions of Dodge'em
  • all Mythicon games are (you guessed it) nearly identical
  • in Music Machine there seems to be some stolen Kaboom-code
    (MM has a religious backgroud, so perhaps the hand of god helped a little ;)
  • Motocross Race borrowed at Pole Position
  • Brick Kick borrowed at Pac Man
    (obviously they borrowed the "flicker routine" ;)