
puzzle -- '15' Puzzle (1.2) : external command / by Jeff Hansen

syntax:  puzzle

ex:      puzzle
         rep 20; puzzle
         spool =:txt; puzzle

Puzzle is a Davex external command similar to the Macintosh desk accessory of
the same name.  It is an implementation of the '15' Puzzle that was the rage
in the 1870's.  These puzzles were composed of 15 numbered wooden blocks and
a tray.  Modern versions, found in some novelty stores, are plastic, and
composed of one unit, as not to lose the pieces.

The object of the puzzle is to arrange the numbers into natural order, with
the blank space in the lower right position.  A move consists of 'sliding'
a block into the blank space.  This has the effect of exchanging the
positions of the block and the space.

The cursor is moved by the arrows, and the keys I, J, K, and L.  Pressing
<space> or <return> with the cursor on a block adjacent to the blank space
(not diagonal!), will move the block into the blank space.  The bell will
ring if you attempt an invalid move.  Pressing <esc> will exit.  Upon
completion of the puzzle, press any key to return to Davex.  Version 1.2
adds Mouse (if present) support, in addition to the keyboard commands.

Puzzle will work while 'spooling' files to the printer, so you can entertain
yourself while printing those big documents.

(see also: spool)
