Tile World's Emulation of the Lynx Ruleset
Tile World's emulation of the Lynx ruleset intentionally diverges from
the original Atari implementation in a few minor aspects. These
differences are allowed to stand because:
they are not seen as important to the structure of the original
ruleset, and/or they are clearly due to limitations of the hardware
that the game was originally created for;
they are difficult or impossible to be observed in the original level
retaining them would place limits the sorts of levels that can be
created in the future, in return for little or no improvement in
playability or aesthetic appeal.
Of course, these criteria are partly subjective, and while the author
listens to the opinions of the general community, in the end he
follows his own judgement.
(These criteria also reflect the different statuses of the MS and Lynx
games. The MS game is widely played, and its odd ruleset is carefully
examined for any advantage it can give in increasing scores. In
contrast, the Lynx game was hardly played at all at the time Tile
World was first conceived, and few people knew much about its
internals or the inconsistencies in its ruleset. Because of this
discrepancy, Tile World's emulation of the Lynx game was pursued
mainly to revive a game that was on the verge of becoming moribund.
Emulation of the MS game, on the other hand, was of little interest to
the community unless it was as accurate as possible.)
The specific differences that exist between the original Atari Lynx
implementation and Tile World's Lynx ruleset are as follows.
On the Atari Lynx, no more than 128 creatures could exist at one time.
Attempting to create a 129th creature with a clone machine would cause
it to "run out". Tile World imposes no such limit.
On the Atari Lynx, Chip could hold no more than 255 of each type of
key. If a 256th key was picked up, Chip's inventory for that key would
reset to zero. Tile World imposes no such limit.
On the Atari Lynx, attempting to move off the edge of the map had
unpredictable results. Sometimes it would allow you to wrap around,
but it might also cause bizarre changes to the game's state. Tile
World consistently prohibits movement beyond the map's edge.
Blobs have random movement which changes with each play of a level, in
contrast with walkers, whose random movement is always the same. On
the Atari Lynx, this was done by having the blobs' random numbers
augmented with the current timer value, which meant that there were
really only four possible random-number sequences for the blobs, and
it could be controlled by controlling the stepping. (This also meant
that a walker could become unpredictable in its movement if the level
also contained a blob.) Tile World avoids having blobs become
predictable by giving them a completely separate random-number
The Atari Lynx did not permit arbitrary wiring of buttons. Brown
buttons were automatically connected to the next bear trap in reading
order (scanning to the right, then along the next row going down, and
restarting at the top if the bottom is reached, until a beartrap is
found), and likewise with red buttons and clone machines. Tile World
follows the explicit wiring information present in the data file.
On the Atari Lynx, there were no Wall North or Wall West tiles. These
two tiles were introduced by the MS version, even though they do not
appear in the original level set. Tile World nonetheless permits these
tiles to be used in Lynx levels.
In a simliar vein, the MS data file format permits various kinds of
"invalid" level sets that would be impossible to define for the Atari
Lynx, due to using a completely different data format. Tile World
nevertheless sometimes permits these levels to be played, if the
divergence is minor enough.
Note that, with the exception of the blobs' random movement, all of
the differences listed here can be suppressed by running Tile World in
"pedantic mode". This is done by supply the -P option on the
command line. When Tile World is running in pedantic mode, it will
e.g. ignore the wiring information in the data file and connect
buttons in reading order.
Note that solution files created under Lynx pedantic mode may very
well not work in normal Lynx mode, and vice versa. Tile World does not
keep track of which mode was used when a solution was created. (The
main purpose of supplying pedantic mode is for those who wish to use
Tile World to test levels that are ultimately meant to be played with
the original game, either on actual Lynx hardware or on one of its