Author: Robert Hyatt
Date: 11:39:44 03/29/01
Go up one level in this thread
On March 29, 2001 at 11:34:46, Bertil Eklund wrote: >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 My grandfather would have simply replied "So? some crap doesn't smell bad. but in general..." :)
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