chess.6

UNIX v6源代码 这几乎是最经典的unix版本 unix操作系统设计和莱昂氏unix源代码分析都是用的该版

.th CHESS VI 11/1/73
.sh NAME
chess \*- the game of chess
.sh SYNOPSIS
.bd /usr/games/chess
.sh DESCRIPTION
.it Chess
is a computer program that plays class D chess.
Moves may be given either in standard (descriptive) notation
or in algebraic notation.
The symbol `+' is used to specify check;
`o-o' and `o-o-o' specify castling.
To play black, type `first';
to print the board, type an empty line.
.s3
Each move is echoed in the appropriate notation followed by
the program's reply.
.sh FILES
/usr/lib/book		opening `book'
.sh DIAGNOSTICS
The most cryptic diagnostic is `eh?' which
means that the input was syntactically incorrect.
.sh WARNING
Over-use of this program
will cause it to go away.
.sh BUGS
Pawns may be promoted only to queens.