-Movement commands within the same update "overwrite" each other, in a sense.
-.SH THE HISTORY OF SAIL
-I wrote the first version of
-.I Sail
-on a PDP\-11/70 in the fall of 1980.
-Needless to say, the code was horrendous,
-not portable in any sense of the word, and didn't work.
-The program was not
-very modular and had fseeks() and fwrites() every few lines.
-After a tremendous rewrite from the top down,
-I got the first working version up by 1981.
-There were several annoying bugs concerning firing broadsides and
-finding angles.
-.I Sail
-uses no floating point, by the way, so the direction routines are rather
-tricky.
-Ed Wang rewrote my angle() routine in 1981 to be more correct (although
-it still doesn't work perfectly), and he added code to let a player select
-which ship he wanted at the start of the game (instead of the first one
-available).
-.PP
-Captain Happy (Craig Leres) is responsible for making
-.I Sail
-portable for the first time.
-This was no easy task, by the way.
-Constants like 2 and 10 were very frequent in the code.
-I also became famous for using "Riggle Memorial Structures" in
-.I Sail.
-Many of my structure references are so long that they run off the line
-printer page.
-Here is an example, if you promise not to laugh.
-.br
-.sp
-.ce
-specs[scene[flog.fgamenum].ship[flog.fshipnum].shipnum].pts
-.br
-.sp
-.PP
-.I Sail
-received its fourth and most thorough rewrite in the summer and fall
-of 1983.
-Ed Wang rewrote and modularized the code (a monumental feat)
-almost from scratch.
-Although he introduced many new bugs, the final result was very much
-cleaner and (?) faster.
-He added window movement commands and find ship commands.
-.SH HISTORICAL INFO
-Old Square Riggers were very maneuverable ships capable of intricate