FROTZ(6)FROTZ(6)NAMEfrotz - interpreter for Infocom and other Z-Machine games
SYNOPSISfrotz [options] file
DESCRIPTION
Frotz is a Z-Machine interpreter. The Z-machine is a virtual machine
designed by Infocom to run all of their text adventures. It went
through multiple revisions during the lifetime of the company, and two
further revisions (V7 and V8) were created by Graham Nelson after the
company's demise. The specification is now quite well documented; this
version of Frotz supports version 1.0.
This version of Frotz fully supports all these versions of the Z-
Machine except for version 6. Version 6 is semi-supported by display‐
ing the outlines of V6 graphics with the picture number in the bottom-
right corner.
OPTIONS-a Watch attribute setting. Setting and clearing of attributes on
objects will be noted in debugging messages.
-A Watch attribute testing. Every time the z-machine tests an
attribute value, the test and the result will be reported.
-b <colorname>
Sets the default background color. <colorname> corresponds to
one of the Z-machine colors, which are as follows:
black red green yellow blue magenta cyan white
If color support is disabled or not available on your terminal,
this option does nothing.
-c N Sets the number of context lines used. By default, after a
``[MORE]'' prompt, and assuming there is enough output pending,
Frotz will allow all the currently visible lines to scroll off
the screen before prompting again. This switch specifies how
many lines of text Frotz will hold over and display at the top
of the next screen.
-d Disable color.
-e Enable sound. If you've disabled sound in a config file and
want to hear sound effects, use this.
-f <colorname>
Sets the default foreground color. <colorname> corresponds to
one of the Z-machine colors, which are as follows
black red green yellow blue magenta cyan white
If color support is disabled or is not available on your termi‐
nal, this option does nothing.
-F Force color mode. If you've disabled color in a config file and
want to Frotz to display colors, use this.
-h N Manually sets the screen height. Though most curses libraries
are intelligent enough to determine the current width from the
terminal, it may sometimes be necessary to use this option to
override the default.
-i Ignore fatal errors. If a Z-Machine interpreter encounters a
zcode error such as division-by-zero or addressing an illegal
object, the proper response is to abort execution. This is done
because the zcode program doesn't have a clear idea of what is
going on. There are some games out there that cause fatal
errors because the authors were careless and used an interpreter
that didn't properly check for errors. This option is intended
to get around such bugs, but be warned that Strange Things may
happen if fatal errors are not caught.
-l N Sets the left margin, for those who might have specific format‐
ting needs.
-o Watch object movement. This option enables debugging messages
from the interpreter which describe the moving of objects in the
object tree.
-O Watch object location. These debugging messages detail the
locations of objects in the object tree.
-p Plain ASCII output only. This inhibits the output of accented
letters and other characters from the Latin-1 character set,
replacing them with reasonable alternatives. This may be neces‐
sary on devices lacking these characters.
-P Alter the piracy opcode. The piracy opcode was never used by
Infocom. This switch is really only useful for those who like
to toy around with Z-code.
-q Quiet. Turns off sound effects. Useful when running Frotz on a
remote machine and you don't want to bother whoever's near the
console with weird noises.
-r N Sets the right margin.
-s N Set the random number seed value. The given seed value is used
as the initial seed value on every restart. This is helpful for
testing games like Curses which make random decisions before the
first input (such that the hot key Alt-S does not really help).
-S N Set the transcript width. By default your transscript files are
formatted to a width of 80 columns per line, regardless of the
current screen width. This switch allows you to change this
setting. In particular, use -S 0 to deactivate automatic line
splitting in transscript files.
-t Sets the z-machine's Tandy bit, which may affect the behavior of
certain Infocom games. For example, Zork I pretends not to have
sequels, and Witness has its language toned down.
-u N Sets the number of slots available for Frotz's multiple undo
hotkey (see below). This defaults to twenty, which should be
sufficient for most purposes. Setting too high a number here
may be dangerous on machines with limited memory.
-w N Manually sets the screen width. Again, this should not be nec‐
essary except in special circumstances.
-x Expand the abbreviations "g", "x", and "z" to "again", "exam‐
ine", and "wait". This switch is for use with old Infocom games
that lack these common abbreviations which were introduced in
later games. Use it with caution: A few games might use "g",
"x" or "z" for different purposes.
-Z N Error checking mode.
0 = don't report errors.
1 = report first instance of an error.
2 = report all errors.
3 = exit after any error.
Default is 1 (report first instance of an error).
CONFIGURATION FILES
On startup, frotz will first check the system's frotz.conf then
$HOME/.frotzrc for configuration information. The configuration file
uses a simple syntax of
<variable> <whitespace> <value>
Color names may be any of the following:
black | red | green | blue | magenta | cyan | white
ascii on | off
Use plain ASCII only. Default is "off".
background <colorname>
Set background color. Default is terminal's default background color.
color yes | no
Use color text. Default is "yes" if supported.
errormode never | once | always | fatal
Set error reporting mode.
never Don't report any errors except for fatal ones.
once Report only the first instance of an error.
always Report every instance of an error.
fatal Abort on any error, even non-fatal ones.
Default is "once".
expand_abb on | off
Expand abbreviations. Default is off. Expand the abbreviations "g",
"x", and "z" to "again", "examine", and "wait". This switch is for use
with old Infocom games that lack these common abbreviations which were
introduced in later games. Use it with caution. A few games might use
the "g", "x", or "z" for different purposes.
foreground <colorname>
Set foreground color. Default is terminal's default forground color.
ignore_fatal on | off
Ignore fatal errors. If a Z-Machine interpreter encounters a zcode
error such as division-by-zero or addressing an illegal object, the
proper response is to abort execution. This is done because the zcode
program doesn't have a clear idea of what is going on. There are some
games out there that cause fatal errors because the authors were care‐
less and used an interpreter that didn't properly check for errors.
This option is intended to get around such bugs, but be warned that
Strange Things may happen if fatal errors are not caught.
Default is "off"
piracy on | off
Alter the piracy opcode. Default is off. The piracy opcode was never
used by Infocom. This option is only useful for those who like to toy
around with Z-code.
randseed <integer>
Set random number seed. Default comes from the Unix epoch.
sound on | off
Turn sound effects on or off. Default is "on".
tandy on | off
Set the machine's Tandy bit. This may affect the behavior of certain
Infocom games. For example, Zork I pretends not to have sequels, and
Witness has its language toned down. Default is "off".
undo_slots <integer>
Set number of undo slots. Default is 500.
zcode_path /path/to/zcode/files:/another/path
Set path to search for zcode game files. This is just like the $PATH
environmental variable except that you can't put environmental vari‐
ables in the path or use other shortcuts. For example,
"$HOME/games/zcode" is illegal because the shell can't interpret that
$HOME variable.
The following options are really only useful for weird terminals, weird
curses libraries or if you want to force a certain look (like play in
40-column mode).
context_lines <integer>
Set the number of context lines used. By default, after a ``[MORE]''
prompt, and assuming there is enough output pending, frotz will allow
all the currently visible lines to scroll off the screen before prompt‐
ing again. This switch specifies how many lines of text frotz will
hold over and display at the top of the next screen. Default is "0".
left_margin <integer>
Set the left margin. This is for those who might have special format‐
ting needs.
right_margin <integer>
Set the right margin. This is for those who might have special format‐
ting needs.
screen_height <integer>
Manually set screen height. Most curses libraries are intelligent
enough to determine the current width of the terminal. You may need to
use this option to override the default.
screen_width <integer>
Manually set screen width. Again, this should not be necessary except
in special circumstances.
script_width <integer>
Set the transcript width. Default is 80 columns per line, regardless
of the current screen width. This switch allows you to change this
setting. You may set this to "0" to deactivate automatic line-split‐
ting in transcript files.
The following options are mainly useful for debugging or cheating.
attrib_set on | off
Watch attribute setting. Setting and clearing of attributes on objects
will be noted in debugging messages. Default is "off"
attrib_test on | off
Watch attribute testing. Every time the z-machine tests an attribute
value, the test and the result will be reported. Default is "off".
obj_loc on | off
Watch object location. These debugging messages detail the locations
of objects in the object tree. Default is "off".
obj_move on | off
Watch object movement. This option enables debugging messages from the
interpreter which describe the movement of objects in the object tree.
Default is "off".
ENVIRONMENT
If the ZCODE_PATH environmental variable is defined, frotz will search
that path for game files. If that doesn't exist, INFOCOM_PATH will be
searched.
FURTHER INFORMATION
A git(1) repository of all versions of Unix Frotz back to 2.32 is
available for public perusal here:
https://github.com/DavidGriffith/frotz/.
The bleeding edge of Frotz development may be followed there. A wiki
summarising Frotz is also there at this URL:
https://github.com/DavidGriffith/frotz/wiki/
Source tarballs are available at the IF Archive or any of its many mir‐
rors:
http://www.ifarchive.org/
Most distributions of Linux and BSD include Frotz in their package
repositories.
CAVEATS
The Z Machine itself has trouble with the concept of resizing a termi‐
nal. It assumes that once the screen height and width are set, they
will never change; even across saves. This made sense when 24x80 ter‐
minals were the norm and graphical user interfaces were mostly unknown.
I'm fairly sure there's a way around this problem, but for now, don't
resize an xterm in which frotz is running. Also, you should try to
make sure the terminal on which you restore a saved game has the same
dimensions as the one on which you saved the game.
You can use a path like "/usr/local/games/zcode:$HOME/zcode" with
$ZCODE_PATH or $INFOCOM_PATH because the shell will digest that $HOME
variable for you before setting $ZCODE_PATH. While processing
frotz.conf and $HOME/.frotzrc, a shell is not used. Therefore you can‐
not use environmental variables in the "zcodepath" option within the
config files.
This manpage is not intended to tell users HOW to play interactive fic‐
tion. Refer to the file HOW_TO_PLAY included in the Unix Frotz docu‐
mentation or visit one of the following sites:
http://www.microheaven.com/ifguide/
http://www.brasslantern.org/beginners/
http://www.musicwords.net/if/how_to_play.htm
If you prefer a PDF file of how to play, here is one:
http://inform-fiction.org/I7Downloads/Examples/dm/IntroductionToIF.pdf
BUGS
This program has no bugs. no bugs. no bugs. no *WHAP* thank you. If
you find one, please report it to the Github site referenced above in
FURTHER INFORMATION.
AUTHORS
Frotz was written by Stefan Jokisch for MSDOS in 1995-7.
The Unix port was done by Galen Hazelwood.
The Unix port is currently maintained by David Griffith <dave@661.org>.
SEE ALSOdfrotz(6)nitfol(6)rezrov(6)jzip(6)xzip(6)inform(1)
2.44 FROTZ(6)
