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title: Excalibur Mirage

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Excalibur Mirage [1] Excalibur Mirage,

a robot type dedicated chess computer by Excalibur Electronics, released in 1996 [2]. The computer features a X-Y plotter type actuator with motor driven leadscrews and solenoid able to pick up and move the magnetic pieces, a sensory board, LCD, and a control button panel. The program is Ron Nelson's initial chess program developed for Excalibur, and ran on Hitachi's H8 controller at 10 MHz with 48 KiB ROM and 2 KiB RAM. The development was supported by chess consultant and opening book author Larry Kaufman [3] [4].

Failure Rates

Quote by Ron Nelson [5]

But the Pop-Up Tent, Inc mechanical “engineer”, screwed up on the Mirage housing design and the main motor mounting was off axis and caused high [failure rates](https://en.wikipedia.org/wiki/Failure_rate).

Attack Maps

Quote by Ron Nelson [6]

In 1981 at the [California ACM Computer Chess Tournament](ACM_1981 "ACM 1981"), [Kathy](Kathe_Spracklen "Kathe Spracklen") introduced me to their friend [Ken Thompson](Ken_Thompson "Ken Thompson"). I asked him about his [Belle](Belle "Belle") hardware chess machine, and he was quick to explain how the Hardware [Attack Bitmaps](Attack_and_Defend_Maps "Attack and Defend Maps") worked. I realized that attack bitmap approach was now in a [Chess Challenger](Chess_Challenger "Chess Challenger"), but in software. I used the Belle Attack Map generation on my [H8](H8 "H8") program.

Tactical Quiescence

Further Quote by Ron Nelson [7]

But it was my watching the [games](Chess_Game "Chess Game") and the [PRVs](Principal_Variation "Principal Variation") like you do, and we did at [ACM tournaments](ACM_North_American_Computer_Chess_Championship "ACM North American Computer Chess Championship") that started me asking questions of [Dan](Dan_Spracklen "Dan Spracklen"). Why can we not [generate](Move_Generation "Move Generation") [checks](Check "Check") in the [quiescent search](Quiescence_Search "Quiescence Search")? He said because it would [blow up](Search_Explosion "Search Explosion") the [search](Search "Search") and slow down. Ok, I said, but what if we only generated checks that didn't occur as often, like a knight check that [forked](Double_Attack "Double Attack") a major piece. He said, ummm,,, that would not take much and the search would not blow up.  So that is how we slowly started developing a [tactical](Tactics "Tactics") quiescent search that had all of the things a strong chess player explores when thinking of a tactical position. But I would see that the PRV was missing these obvious strong player "tricks" and have Dan look to see if he could add them. Because of the attack map, all this type of information was easily divined. At the [Micro Tournament](WMCCC_1988 "WMCCC 1988") in Spain, it was music to my ears to have the Chess Master commentator, perhaps [Mike Valvo](Michael_Valvo "Michael Valvo"), say The [Fidelity](Fidelity "Fidelity") unit was playing moves it had never before been capable of playing. Just like the Masters we played to get the certified rating, who were amazed.


I used this same type of tactical threat generation on the H8 machine, since I had attack maps with the needed information.

See also

Manual

Forum Posts

Excalibur Electronics by ChessChallenger, Hiarcs Forum, December 22, 2015 Excalibur Electronics by ChessChallenger, Hiarcs Forum, December 22, 2015 Ron Nelson by ChessChallenger, Hiarcs Forum, December 23, 2015 » Excalibur Ron Nelson by ChessChallenger, Hiarcs Forum, December 23, 2015 » Fidelity Electronics, Sidney Samole Re: Ron Nelson by ChessChallenger, Hiarcs Forum, December 24, 2015 » Excalibur Mirage, Eric White Re: Ron Nelson by ChessChallenger, Hiarcs Forum, December 29, 2015

Chess Products Ron Nelson designed/programmed by ChessChallenger, Hiarcs Forum, January 11, 2016

External Links

Chess Computer

Misc

References

  1. ↑ Capture from the Video
  2. ↑ Chess Products Ron Nelson designed/programmed by ChessChallenger, Hiarcs Forum, January 11, 2016
  3. ↑ Excalibur Electronics by ChessChallenger, Hiarcs Forum, December 22, 2015
  4. ↑ Re: Ron Nelson by ChessChallenger, Hiarcs Forum, December 23, 2015
  5. ↑ Ron Nelson by ChessChallenger, Hiarcs Forum, December 23, 2015
  6. ↑ Excalibur Electronics by ChessChallenger, Hiarcs Forum, December 22, 2015
  7. ↑ Re: Ron Nelson by ChessChallenger, Hiarcs Forum, December 29, 2015

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