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Subject: Re: Good old days, early '80s

Author: Bas Hamstra

Date: 01:13:58 11/25/99

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On November 24, 1999 at 00:02:02, Christophe Theron wrote:

>On November 23, 1999 at 22:53:11, Dave Gomboc wrote:
>
>>On November 23, 1999 at 11:59:46, Christophe Theron wrote:
>>
>>>On November 23, 1999 at 03:54:48, Ed Schröder wrote:
>>>
>>>>>Posted by Christophe Theron on November 22, 1999 at 18:25:35:
>>>>>
>>>>>>>Was it better than Sargon II, or just equal?
>>>>>>
>>>>>>It was better because Sargon was outplayed by search depth in most
>>>>>>cases. In that days Rebel was able to look 6 plies deep all very selective
>>>>>>and much holes involved but very effective playing a program thinking
>>>>>>just 4 plies deep.
>>>>>
>>>>>6 plies on a TRS-80 in the time Sargon took to compute 4?
>>>>>
>>>>>I have the old Sargon II for TRS-80 manual just in front of me. A green manual:
>>>>>"Hayden computer program tapes, Sargon II: A computer chess program by Dan and
>>>>>Kathe Spracklen". I have kept it as a souvenir (I also have the cassette,
>>>>>but I don't dare to open the box).
>>>>>
>>>>>The manual says that it took 6 minutes (average) to compute to ply depth 4.
>>>>>
>>>>>You are saying that in 6 minutes you were able to compute to ply depth 6 on a
>>>>>TRS-80???
>>>>
>>>>6 plies indeed all very selective but a friend of mine had doubled the
>>>>processor speed from 1.77 Mhz to 3.5 Mhz. On standard 1.77 Mhz Rebel on
>>>>40/120 was only able to compute 4 plies and some moves on 6 plies.
>>>>
>>>>The first Rebel was a strange animal. I had to re-invent the wheel
>>>>completely as I had no access to documentation, I wasn't even aware
>>>>documentation existed.
>>>>
>>>>No alpha/beta, no windows, no Q-search, the program could only think
>>>>in steps of 2 plies. Thus 2,4,6,8 etc.
>>>
>>>
>>>???
>>>
>>>How did it work? Why the always even depth?
>>
>>Maybe he had a big odd/even effect.  Funny that he didn't choose 1, 3, 5, 7 ...
>>though.
>>
>>Dave
>
>
>From the text I understood it was a search issue. But I don't see why, that's
>why I ask...
>
>The reason I'm interested in this is that in the early days of computer chess
>programming, people did not know what were the efficient ways to do it. So they
>tried to invent their own algorithms.
>
>Some of them are maybe the future of chess programming.
>
>That was one of my objections to the Crafty or GnuChess project. Reinventing the
>wheel IS fun. Today many chess programs are almost identical. Where is all that
>creativity gone?
>
>God. I'm speaking like Chris W. now!
>
>I like to hear about exotic algorithms designed at the time when the computers
>were very slow.
>
>
>
>    Christophe



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