SciSys Mark V Prototype
SciSys Mark V Prototype 1 25 x 25

There is reason to believe that this chess computer is unique. It is a prototype, forerunner of the SciSys Chess Champion Mark V which won the World Microcomputer Chess Championship (Commercial Group) at Travemunde, West Germany, 21 - 27th September 1981. Several prototypes were built. In particular a team of prototypes contested the Asian Cities Team Championships held in Hong Kong in February 1981. This one stayed in Europe where it was demonstrated at tournaments and exhibitions, and shown to journalists and prospective commercial partners.

Back in the 1980s it was usual for development machines and prototypes to be scrapped or cannibalised for parts after their immediate purpose was fulfilled, and it is probable that all the other prototypes will have been scrapped. That this particular prototype survived is down to Kevin O’Connell (link 1) and the fact that three chess Grandmasters autographed the Prototype in Hamburg, West Germany in April 1981. Even then it is probably the fact that Mikhail Botvinnik’s was one of those autographs which saved this particular machine. Botvinnik was the World Chess Champion 1948-57, 1958-60 and 1961-63, one of the greatest players of all-time and teacher of World Champions Karpov, Kasparov and Kramnik, in addition to being a computer chess expert. So it was the autograph(s) rather than the Prototype itself that was thought sufficiently valuable to keep stored in a cellar, a cupboard and a storage box through the 1980s and 90s. With the more recent resurgence in interest in old chess computers perhaps it is the machine itself, rather than the autographs, which deserves some attention now.

In 2000 the Prototype was included in an internet auction, bundled with a Mark V, just one item in an extensive collection of chess books, equipment and memorabilia which Kevin O’Connell had decided to clear (link 2 - catalogue). The Mark V and Prototype did not sell but they resurfaced again in 2005 when Lesley O’Connell, Kevin’s wife, placed them on Ebay. The lot was sold to a German collector for 314.12, without the Prototype’s power supply, and with no guarantee that it worked (link 3). In fact it did not work and there is an email to the buyer from Lesley and Kevin O’Connell explaining its history (link 4). However it was then expertly repaired by Arno Kreuzberg who built a new power supply for it, and it has been well looked after ever since. In 2009 the owner played it in an online tournament, where it scored 5/9 in an U1500 Elo group (link 5 and link 6).

Now the Prototype is back in Britain where it was originally developed and programmed. It’s history is probably as well documented as any chess computer of that pre-internet era, thanks to the involvement of prolific authors David Levy and Kevin O’Connell. On this webpage much of the available information is brought together to give an explanation and the history of the Prototype. At the bottom of the page are links to these and other relevant articles and websites.

SciSys Mark V Prototype 4 15 x 15

The project which was to reach fruition with the Chess Champion Mark V was born in late March 1980 at a meeting between David Broughton, David Levy and Kevin O’Connell. David Broughton was chief programmer at Philidor Software, hired by Levy and O’Connell after his Vega program came second to Sargon winning the Amateur prize at the PCW Microcomputer Chess Championships in 1979. At the meeting it was agreed to develop a chess computer program, to be called Philidor, incorporating Philidor Software’s emerging selective search ideas (link 7). Work started on the program at the end of May 1980.

SciSys Mark V Prototype 2 10 x 10
SciSys Mark V Prototype 3 10 x 10

By November 1980, still without an openings library, Philidor was able to match Broughton, its author, rated approximately 1700 Elo. Satisfied with progress thus far there followed a period of testing against commercial chess computers already on the market. In December 1980 a small openings library was added and the Prototype you see was entered in the Islington Christmas Congress in London scoring 2 1/2 out of 6, equivalent to a 1700 Elo rating. [Note chess computer Elos at this time were inflated, partly because club chess players were not as knowledgeable about how to beat them as they soon became]

At the beginning of February 1981 the Prototype travelled around Europe visiting various cities including Copenhagen, Dortmund, Frankfurt and the International Toy Fair at Nurnberg. There it was demonstrated to a number of German computer chess journalists including Frederic Friedel, Bjorn Schwarz and Ivan Kuhnmund, receiving good feedback in particular for its playing style which was more positional than most chess computers of the time, which had brute force strategies and a tendency to grab material whatever.

Also in February a team of four prototypes competed in the Asian Cities Team Championship in Hong Kong against strong opposition resulting in a performance rating of 1860 Elo from 5 wins, 2 draws and 19 losses.

Early in March 1981 the Prototype competed at Computachess ‘81, a Man-Machine five round Swiss tournament played at Trinity College, University of Dublin. The tournament and its chess computers are reported at length in Tim Harding’s “The Chess Computer Book” (link 8).

On April 9th and 10th 1981, the “Advances in Computer Chess 3” conference was held at Imperial College, London. Ken Thompson attended and brought with him a transportable (1979) version of BELLE, the World Computer Chess Champion. Even without its larger openings book or transposition tables BELLE was still a formidable opponent  and the opportunity was taken for a two game friendly match between the Prototype and BELLE. The Prototype won with white, a game published here (link 9).

On April 12th 1981 the Prototype was at a simultaneous exhibition in Hamburg where Mikhail Botvinnik beat the Prototype in 32 moves and Ludek Pachman beat it in 54 moves. It was then, at the end of its brief period in the limelight, that the Prototype was signed by chess Grandmasters Botvinnik, Pachman and Pfleger.


Mikhail Botvinnik and his autograph which looks nothing like Botvinnik in Latin script.
Below Helmut Pfleger and Ludek Pachman

Botvinnik autograph 4

From May 1981 the Prototype was replaced in tournament and demonstration appearances by pre-production Mark V’s.
On May 28th - 31st 1981 one of these early Mark V’s competed at the Paris Chess Programs World Tournament where the Philidor team were disappointed to come second to Mephisto Experimental X with a 5/7 score.. A tournament report by Kevin O’Connell can be found here (link 10).

In June 1981 work finished on the public version of Philidor, i.e. the version released for sale in the Chess Champion Mark V, which was then planned to hit the market in September. By then work had already started on Philidor 2, which was eventually to appear as the Mark VI / Philidor module (link 11).

Between 21st and 27th September 1981 the World Microcomputer Chess Championships were held at Travemunde, West Germany. There an early production Mark V won the Commercial Group and became World Champion. There are plenty of sources of information available on this tournament but you can find an article by David Levy and Kevin O’Connell here (link 12).


SciSys Mark V Prototype 10 20 x 20

A Mark V and the Mark V Prototype side by side.
Apart from the LCD chessboard and main keypad there are few similarities between the development machines and the final product.

SciSys Mark V Prototype 11 15 x 15
SciSys Mark V Prototype 9 10 x 10
SciSys Mark V Prototype 8 10 x 10
SciSys Mark V Prototype 5 25 x 25

As can be seen from the photographs the Prototype contains a Z80A processor and was therefore at the end of its working life still using David Broughton’s program rather than Mark Taylor’s rewrite/conversion for the 6502 processor. By March 1981 six programmers, including Broughton, were devoting some of their time to the Philidor project as it neared completion. In addition to providing overall direction David Levy had been involved with developing the heuristics for the project and provided the opening book. Kevin O’Connell looked after the business side as well as operating and demonstrating the Prototype at tournaments, conferences, exhibitions and private meetings. So Philidor was a team effort.

David Broughton discusses his contribution to the Philidor project in an interview with Bernhard Drexler for Wiki to be found here (link 13). In a similar interview with David Levy (link 14) credit for the final Mark V program is given to Mark Taylor. It was reported in an article by Gerd Friedrich (Rochade magazine July 1981) that the Prototype with Z80 processor played 3-4 times slower than the final Mark V with Mark Taylor’s rewritten program. I shall do some testing and add some games between the Prototype and Mark V to this article in due course. For now you will find one game from the 2009 Online Tournament below.

SciSys Mark V Prototype 6 50 x 50

Inside the Mark V Prototype can be found a Z80A processor date stamped 7829, two Z80-P10 Input/Output devices and multiple TMS 2516JL-35 2KB EPROMs. The crystal is stamped 655 3.6 kHz. The photo below shows the back of the LCD chessboard.

SciSys Mark V Prototype 12 15 x 15 SciSys Mark V Prototype 7 Cropped 80 x 80



1. “Chess Computers - The UK Story” at
2. “Chess & The Library of Kevin O’Connell” Phillips Auctioneers catalogue 7th November 2000.
3. Ebay auction for the SciSys Chess Champion Mark V + Prototype dated 18th November 2005.
4. Email from Ebay seller to buyer dated 29th November 2005.
5. Online Tournament U1500 Elo Group 2009.
6. 2009 Online Tournament games in PGN format.
7. “SEX Algorithm In Computer Chess (Search EXtension) 1989” at Chess Programming from the ICGA Journal paper Vol.12 No.1
8. “The Chess Computer Book” Timothy Harding, Pergamon Press, January 1982.
9. “The Best Chess Computer Yet?” article by David Levy and Kevin O’Connell published in Chess, July 1981.
10. Report on the Paris Chess Programs World Tournament (May 28th-31st 1981) by Kevin O’Connell in Personal Computer World August 1981.
11. SciSys Chess Champion Mark VI + Sensor Board at
12. “A New World Champion” article by David Levy and Kevin O’Connell published in Chess, October-November 1981.
13. David Broughton interview by Bernhard Drexler for Wiki, February 2006.
14. David Levy interview by Bernhard Drexler for Wiki, February 2006.

   Hein Veldhuis’s webpage on the SciSys Chess Champion Mark V Prototype
   ICGA Tournaments - 2nd World Microcomputer Chess Championship (Commercial), Travemunde, West Germany - Download Games
   SciSys Chess Champion Mark V @ Wiki (German and English)
   SciSys Chess Champion Mark V @


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