Author: Bertil Eklund
Date: 08:34:46 03/29/01
Go up one level in this thread
On March 29, 2001 at 10:54:38, Robert Hyatt wrote: >On March 29, 2001 at 09:24:12, Ed Schröder wrote: > >>On March 29, 2001 at 07:43:53, pete wrote: >> >>>On March 29, 2001 at 00:22:03, Robert Hyatt wrote: >>> >>>>> >>>>>There was an extremely nice answer to this and similar posts published in the >>>>>German CSS magazine in an article by Chrilly Donninger some time ago. >>>>> >>>>>It would simply be great if it could be put to the Web ; it explained how the >>>>>autoplayer started and developped and really opened my eyes . >>>>> >>>>>After reading it I understood the problems of the autoplayer and the reasons for >>>>>them much better . >>>>> >>>>>I don't know who holds the rights for it but it was >>>>> >>>>>a.) very convincing >>>>>b.) understandable to any non-programmer guy , too . >>>>> >>>>>pete >>>> >>>> >>>>Don't believe everything you read. >>> >>>Thanks for the tip . >>> >>> I wrote serial I/O multiplexing code >>>>using an 8080 microprocessor. I had _no_ timing dependencies. If you see >>>>old pictures of Cray Blitz and my electronic chess board, you will see a >>>>chess board with a built-in modem, all driven by a Z80 microprocessor. That >>>>thing talked to the cray, to the chess board, and to a dumb terminal so we could >>>>see what the Cray was thinking. Maintaining three separate streams of data >>>>context. Nary a timing issue. >>>> >>>>There were ways to write auto232 without the timing nonsense. It simply wasn't >>>>done. >>>> >>>>And as a result, it belongs in a "hefty bag" if you know what I mean. :) >>> >>>Well , actually I am under the impression you haven't read the article >>>mentioned. Unfortunately the CSS homepage is down and I don't have it handy >>>either currently. From what I remember the autoplayer initially was nothing more >>>than a side-product of the implementation for support of an existing >>>electronical chessboard Auto232 . I don't remember the exact numbers now but the >>>memory limitations were extreme . The article explained the reasons for some >>>technical shortcomings very well . >>> >>>The article agreed that the implementation might not be very well at all and >>>encouraged people to simply write something better if they don't like the >>>product quoting a similar statement from you about Crafty :-). >> >>Yes I remember Chrilly qouting Bob, "auto232 is a piece of junk" with a >>wink. When auto232 came out, I believe it was 1994, it was a sensation. >>Suddenly you could play matches all automatic. It has changed the CC >>community as auto232 rapidly became the key to judge the playing strength >>of new released engines. Piece of junk or not, it still is the key today. >> >>I write this because I feel that using this tool should be discussed >>endlessly, its pro's, its contra's, its bugs. CCC is for 90% about playing >>strength and chess programs are being judged on the use of this fragile >>tool. >> >>In this spirit I have enjoyed Chrilly's contribution because he wrote some >>details I wasn't aware off, and wasn't hiding any quirks of auto232 being >>completely open and honest about a simple idea he once had which changed >>the CC community to a great extend. >> >>Never forget that auto232 is a vulnerable system and many things can go >>wrong. During the beta-poriod of the upcoming Rebel 11 update suddenly >>auto232 complaints from the beta-team came (aborted matches) while nothing >>has been changed in the auto232 code. At first I told the beta-team to >>ignore the complaints saying, "there is nothing changed, auto232 just has >>its own mysterious ways, you never get it optimal". >> >>But Lex could not resist and made changes resulting in a more stabile >>autoplayer. Maybe if Lex reads this he can explain a bit about the nature >>of the changes and why he thinks the autoplayer code suddenly behave >>awkward while nothing had changed. Looking at my own experiences I am >>pretty sure his explanations will be vague, probably related to what Bob >>has been said about "timings", maybe the nowadays faster hardware could >>be an issue too. >> >>Making your engine auto232 compatible is a risky job, a road full of stings, >>you lay your faith in the hands of a fragile master-slave protocol. Bugs in >>the software is almost inevitable because bugs are hard to trace, if not >>impossible. When there is a bug you first have to realize there is one >>because the bug is invisible as in the Rebel case and it took me years to >>realize it and then proof it, which was a story of its own. >> >>To be complete, I don't believe a word of some critical voices who suggest >>deliberate manipulation by producers to get an unfair advantage. Auto232 may >>crash all the time in won/lost or draw positions, it is just random. If there >>are bugs this is not deliberate, it just comes with the nasty protocol you >>are trying to control in which you never will succeed in a 100% successful >>way. >> >>2 hurrays for auto232 as 3 is too much. >> >>Ed >> >> >> >>>pete > > >To me, auto232 pales when compared to the winboard system. I have been using >xboard/winboard to play matches for _years_ and have _never_ had to deal with >introducing delays, varying the delays depending on whether or not I am probing >endgame databases, etc. > >Some of the auto232 ideas were definitely neat. Grabbing a chess move by >watching video RAM. Sending it over an RS232C port. But Jesus, this can be >done without making it highly sensitive to various timing issues. > >I will certainly say one thing. Anybody that writes code with that many timing >holes had better _never_ try to write a parallel chess engine. It will _never_ >be debugged with those kinds of critical design flaws included. > >Writing code to handle asynchronous events is not difficult. In fact, if I >were trying to write a driver that misbehaves as badly as auto232, I really >would not know where to start. It would be very hard for me to write code >that fails or works depending on lots of random timing considerations. > >So conceptually, yes auto232 is great. But its implementation sucks with two >straws. :) Hi! But for some reason you can play houndreds of games in a row with old programs like Fritz3, Genius1-5 and Comet for DOS, against any other program without any problem at all (except under-promotion). Bertil
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