Author: Rolf Tueschen
Date: 23:48:13 08/22/04
Go up one level in this thread
On August 23, 2004 at 02:09:51, Paul H wrote: >On August 23, 2004 at 00:31:53, Rolf Tueschen wrote: > >>On August 22, 2004 at 17:17:25, Paul H wrote: >> >>>The argument here is not based on the output of the engine or the strenght of >>>the engine or the kind of moves that it generates. If ElChinito is only Elo >>>1000, it still does change the fact that the binary ElChinito.exe is made from >>>Crafty source. If it is Elo 1000 using crafty code, it just means that there are >>>changes that made it so. >>> >>>I just did a thorough code analysis. It reveals facts that even Bob only >>>realizes now. Even without the source code, Bob agrees that those portions of >>>code is from Crafty. Again, that is without the source code. Have you seen >>>anyone do this kind of technical analysis here before? And after all that, you >>>compare it to a primitive witch hunt? >>> >>>I am about to also post the disassembly of the function NextMove(). These are >>>all technical facts. >>> >>>Why don't you review all the code analysis and tell us that it is wrong. >> >> >>I am also part of the handful of people in CCC who can't understand code >>analysis or anything with code. Could you please explain to these few what you >>did in your analysis? You say that you can get details of a program's code if >>you have only the exe? - A question in that context would also be, if you could >>clarify if LIST (Graz) was a Crafty clone or at least if it used parts of Bob's >>code? Would your answer be also relevant if say some critics still claimed that >>they had data that LIST in fact were a clone or used parts of its code? - Thank >>you in advance. > >You analyze an exe file by running a disassembler on it. You will get a file in >assembly language. Now you can read it as a computer language, just like you >would read any other computer language (like C/C++, Pascal). When C/C++ code is >turned into an exe file, it is first converted to assembly language. This is the >same assembly language file that you get when you disassemble the exe. You can >also look at the disassembly of an exe by loading it in a debugger. > >Disassembling is the method used when people want to determine what a virus does >(since you don't have the source code of the virus; you only have the infected >exe file). People also use the method to determine how to "crack" a program >(like removing some copy-protection code). It is also the method for determining >if others are using your intelectual property (like if Oracle wants to see if >IBM's DB2 database software is using any Oracle technology) - its much like what >we are doing here between Crafty and ElChinito. > >Btw, to turn C/C++ to assembly language, you don't need a compiler. You can >translate it manually, but it is a lot of work. You can also manually convert an >exe to assembly language. Again, it is a lot of work. > >As for List, I have mentioned this before, that I analyzed version 4.61 of List >and found that it does not use BitBoards at all, and that I could not find any >similarity with Crafty. Dann agrees that it does not use BitBoards because he >has seen the code. > >The effect of not using BitBoards is huge. The attack functions will be very >different. The evaluation functions which rely a lot on computing attacks will >look very different. The move generation will be very different. And with the >use of x88 boards, the board indexing is very different too. > >If one takes some code from Crafty but converts it to a non-bitboard code, the >disassembly with look very different. > >Mind you however, that to convert Crafty to use non-bitboards is a lot of work. >It is not the kind that a cheap cloner will want to do. In such a case, you >could already qualify for copying the idea and not the code. And that would be allowed? This is all indeed breathtaking for me as a lay, but let me finally ask, if you could also decrypt this way how commercial exes would work? Say Fritz or Shredder? And if you did, if they _also_ used at least a little bit of Crafty code? That indeed would set the record straight. Or do they just copy ideas? :) As usual my very last question is still another one. What did you find for RUFFIAN 1 or 2? We were all very surprised that such a prog should be possible completely out of the closet from a newcomer.
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