''Colossus Chess'' is a series of chess-playing computer programs developed by Martin Bryant, commercially released for various home computers in the 1980s.

History

Bryant started ''Colossus Chess'' in 1983, using his '' White Knight Mk 11'' program, winner of the 1983 European Microcomputer Chess Championship, as a basis. It was developed on an

Apple II The Apple II (stylized as ) is an 8-bit home computer and one of the world's first highly successful mass-produced microcomputer products. It was designed primarily by Steve Wozniak; Jerry Manock developed the design of Apple II's foam-mold ...

, but was first commercially released for Commodore 64 as ''Colossus Chess 2.0'' (

CDS Micro Systems CDS Software (also known as CDS Micro Systems for its earlier titles) was an independent publisher and developer of computer game software based in Doncaster, South Yorkshire, UK. History The company was founded by Ian Williams, a computer pro ...

, 1984). A number of releases for 8-bit microcomputers followed. Version 3.0 was released in 1984 for the

Atari 8-bit family The Atari 8-bit family is a series of 8-bit home computers introduced by Atari, Inc. in 1979 as the Atari 400 and Atari 800. The series was successively upgraded to Atari 1200XL , Atari 600XL, Atari 800XL, Atari 65XE, Atari 130XE, Atari 800XE ...

of computers (published by English Software), followed by 4.0 in 1985 which was released on most formats of the day (published by CDS). As other games of the time, the

Acorn Electron The Acorn Electron (nicknamed the Elk inside Acorn and beyond) was a lower-cost alternative to the BBC Micro educational/home computer, also developed by Acorn Computers Ltd, to provide many of the features of that more expensive machine at a p ...

implementation required that part of the screen memory be used as working space. ''Colossus Chess'' featured time-controlled play with game clocks, an opening book with 3,000 positions, and

problem Problem solving is the process of achieving a goal by overcoming obstacles, a frequent part of most activities. Problems in need of solutions range from simple personal tasks (e.g. how to turn on an appliance) to complex issues in business an ...

-solving mode that could solve normal mates, selfmates and

helpmate A helpmate is a type of chess problem in which both sides cooperate in order to achieve the goal of checkmating Black. In a helpmate in ''n'' moves, Black moves first, then White, each side moving ''n'' times, to culminate in White's ''nth'' move ...

s. (product manual) Pondering on opponent's time and a three-dimensional

chessboard A chessboard is a used to play chess. It consists of 64 squares, 8 rows by 8 columns, on which the chess pieces are placed. It is square in shape and uses two colours of squares, one light and one dark, in a chequered pattern. During play, the bo ...

were introduced in ''Colossus Chess 4.0''. All releases were written in the assembly language of the appropriate

CPU A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, and ...

; the

ZX Spectrum The ZX Spectrum () is an 8-bit home computer that was developed by Sinclair Research. It was released in the United Kingdom on 23 April 1982, and became Britain's best-selling microcomputer. Referred to during development as the ''ZX81 Colou ...

version could examine an average of 170 positions per second. Uncommon for microcomputer chess programs of the era, ''Colossus'' had a full implementation of the rules of chess, including underpromotion, the fifty-move rule, draw by repetition, and

draw Draw, drawing, draws, or drawn may refer to: Common uses * Draw (terrain), a terrain feature formed by two parallel ridges or spurs with low ground in between them * Drawing (manufacturing), a process where metal, glass, or plastic or anythin ...

by insufficient material. ''Colossus'' was also able to execute all the basic

checkmate Checkmate (often shortened to mate) is any game position in chess and other chess-like games in which a player's king is in check (threatened with ) and there is no possible escape. Checkmating the opponent wins the game. In chess, the king is ...

s, including the difficult bishop and knight checkmate.

''Colossus Chess X''

The program was subsequently ported to Atari ST (1988),

Amiga Amiga is a family of personal computers introduced by Commodore International, Commodore in 1985. The original model is one of a number of mid-1980s computers with 16- or 32-bit processors, 256 KB or more of RAM, mouse-based GUIs, and sign ...

(1989) and

IBM PC The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a tea ...

(1990) under the title ''Colossus Chess X''. The new releases featured four chess sets and enhanced graphics developed with the assistance of Gary Thomlinson and Carl Cropley. The opening book was extended to 11,000 positions, and the program had the ability to learn from past playing experiences.

UCI version

No work was done on ''Colossus Chess'' from 1991 to 2005, when Martin Bryant created a completely new and freely available Windows version conforming to the

Universal Chess Interface The Universal Chess Interface (UCI) is an open communication protocol that enables chess engines to communicate with user interfaces. History In November 2000, the UCI protocol was released. Designed by Rudolf Huber and Stefan Meyer-Kahlen, the ...

. It was written in C#, then converted to C for speed, and was finally publicly released in 2006. , the latest version is 2008b.

Reception

'' Info'' gave ''Colossus Chess IV'' for the Commodore 64 three stars out of five, stating that it was less attractive but "a darn sight more playable" than '' Chessmaster 2000'' with both keyboard and joystick controls. The magazine warned of the difficulty of remembering the "shifted keyboard control sequences ... badly in need of a quick-reference card".

References

External links

Colossus home page
* * * * *
''Colossus Chess 4.0 product manual'' (C64)
{{BBC Computer Literacy Project 1984 video games 1985 video games 1986 video games 1987 video games 1988 video games 1989 video games 1990 video games Chess engines Amiga games Amstrad CPC games Amstrad PCW games Apple II games Atari 8-bit family games Atari ST games BBC Micro and Acorn Electron games Commodore 16 and Plus/4 games Commodore 64 games DOS games MSX games ZX Spectrum games Video games developed in the United Kingdom