Author: Lex Loep
Date: 11:44:40 03/29/01
Go up one level in this thread
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. Basically I changed some timings, the protocol seems to dictate that characters may not be transmitted to fast so there is a 100ms delay between characters. I also changed some other delays at game end. Further I found a bug in handling one of the chessbase extensions, it could happen that both programs where endlessly sending each other NAK characters. My background is in data communications and as such I can say the protocol is seriously flawed, its a miracle it works most of the time. I think the only reason that it is still around is that it is the only thing that works with most commercial programs. Lex >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
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