
FROTZ V2.41 - an interpreter for all Infocom games. Complies with standard
1.0 of Graham Nelson's specification. Written by Stefan Jokisch in 1995-7

    This program once started as a re-make of Mark Howell's Zip, but
    has grown into an utterly new interpreter.

    Jim Dunleavy <jim.dunleavy@erha.ie> maintains the 32bit DJGPP
    version.

    Please report bugs in Amiga Frotz to <davidk@monis.co.uk>

Copyright:

    Frotz is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
   
    Frotz is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
   
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA

Syntax: frotz [options] story-file

    -i	     ignore fatal runtime errors

    Set this switch and Frotz no longer worries about anything the
    game tries to do. This can help you to get around fatal errors.

    -S #     set the width of the transscript file

    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 -S0
    to deactivate automatic line splitting in transscript files.

    -c #     set the number of context lines

    When the game prints several pages of text in a row, Frotz stops
    for a more prompt after each page. The first prompt appears when
    your input reaches the top of the window. Further prompts appear
    when the previous page has been scrolled off the window. You can
    use this switch to make the latter more prompts appear earlier.

    -u #     set the number of undo slots for multiple undo

    Sets the number of slots available for Frotz's multiple undo hotkey
    (see below). This defaults to 500, which should be sufficient for
    most purposes. Setting too high a number here may be dangerous
    on machines with limited memory. You can turn off the undo feature
    altogether by using -u0.

    -s #     set the random number seed

    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). The meaning of seed values is
    explained in the next section.

    -x       expand abbreviations (g, x, z ==> again, examine, wait)

    This switch was made for old Infocom games that lack the common
    abbreviations introduced in later games. Use it with caution: A
    few games might use "g", "x" or "z" for different purposes.

    -o       watch object movement
    -O       watch object locating
    -a       watch attribute assignment
    -A       watch attribute testing

    Although these switches may be of assistance while debugging new
    games, they are are actually meant to be cheat functions. The -o
    switch, for example, helps to locate the thief in 'Zork 1' and
    the cat in 'Curses'. The other switches produce a lot of obscure
    messages during the game; but some of these messages might give
    you important clues if you watch carefully.

    -t       set the Tandy bit

    Some old Infocom games were sold by the Tandy Corporation. These
    games behave slightly different when you use this option. For
    example, 'The Witness' gets censored: bastards turn into idiots,
    private dicks into private eyes and so on.

    -p       alter behaviour of piracy opcode

    The piracy opcode was never used by Infocom, and this switch is
    only useful for those who like to toy around with Z-code.

    -R       save/restore in old Frotz format

    By default Frotz save files are stored in the Quetzal format.
    If you have save files from earlier versions of Frotz you can
    use the -R switch to restore them.

    -Z #     set error reporting mode

    Available modes are

    0 = no errors are reported
    1 = report first occurence of error (default)
    2 = report all errors
    3 = exit after any error

Special keys:

    Alt-D - toggle debugging options (-a, -A, -o, -O)
    Alt-H - help on hot keys
    Alt-N - new game (restart)
    Alt-P - turn on input line playback
    Alt-R - toggle input line recording on/off
    Alt-S - set the random number seed
    Alt-U - multiple undo, works even for old V1 to V4 games
    Alt-X - exit game

    When testing a text adventure it can be difficult to reproduce a
    specific bug. To avoid this problem you should use the Alt-R key
    to record all your inputs in a command file. Later you can press
    Alt-P to feed the command file back into Frotz. In many cases,
    however, you will find that the result is different because most
    games contain random events. Luckily, Frotz provides a hot key
    to control these events. Type Alt-S and you are asked for a seed
    value, i.e. a value in the range from 1 to 32767. Normally, you
    would choose a number >= 1000. Smaller values generate a special
    sequence of random numbers as proposed by Nelson. (For instance,
    the seed value 4 generates 1, 2, 3, 4, 1, 2, 3, 4, 1...). In any
    case, random events become predictable until the next restart.

    See also the command line option -s above.

    When you need to type an unpleasantly long word, try to type the
    first three or four letters then press the tabulator key. If you
    are lucky, Frotz fills in some or all of the missing letters.

Environment variables:

    If Frotz can't find a game in the current directory it searches
    the semicolon-separated list of paths in the ZCODE_PATH environment
    variable. If ZCODE_PATH is undefined it will try the INFOCOM_PATH
    variable.

Questions and answers:

    Q: What is Frotz?
    A: Frotz runs text adventures which come in so-called story files:
       ZORK1.DAT, TRINITY.DAT, CURSES.Z5, JIGSAW.Z8, ARTHUR.ZIP etc.

    Q: Where can I find story files to use with Frotz?
    A: First, you can use the files from your original Infocom games. It
       is possible to play Atari ST, Amiga or Macintosh games on your PC
       once you manage to transfer the story files. Some people even
       extracted story files from old Atari 800, Apple II and C-64 disks
       (ask your local 8bit guru). Second, there is an increasing number
       of new games available on the Internet. Check the if-archive at
       ftp.gmd.de.

    Q: Why does Frotz stop with an error message?
    A: It might have detected a bug in the story file other interpreters
       overlooked. Use the -i switch to run your story file anyway. It's
       also possible that the story file is corrupt; be sure to download
       story files in binary mode, especially when you use a WWW browser.

    Q: What do I need to play graphic games?
    A: In addition to the story file, you also need appropriate graphics
       files in your current directory. CG1 files work for CGA mode, MG1
       files for both MCGA and AMIGA modes and finally EG1/EG2 files for
       EGA mode. If you extract a story file from Amiga/Macintosh disks,
       you should get the MG1 file from the if-archive at ftp.gmd.de.

    Q: What do I need for sound?
    A: You need the original 'Sherlock' or 'Lurking Horror'. Next get the
       SHSOUND.ZIP or LHSOUND.ZIP package from ftp.gmd.de (directory is
       /if-archive/infocom/missing-files). Each package contains a readme
       file, sound files and a tool to update your old story file. Follow
       the instructions in the readme file.

    Q: When exactly should I hear sound?
    A: Here are two examples: In 'Lurking Horror', you can hear chanting
       during your dream in the terminal pool. In 'Sherlock', you should
       play the violin.

    Q: Why doesn't the sound work?
    A: Be sure to use the correct story files: 'Sherlock' release 26 (not
       release 21) or 'Lurking Horror' release 221 (not release 203). The
       release number is shown at the start of the game.

List of fatal errors:

    - "Bad stack frame"
    - "Byte swapped story file"
    - "Call to illegal address"
    - "Call to non-routine" [1]
    - "Cannot open story file"
    - "Division by zero"
    - "Error reading save file"
    - "Illegal attribute"
    - "Illegal object" [2]
    - "Illegal window"
    - "Illegal window property"
    - "Jump to illegal address"
    - "Nesting stream #3 too deep"
    - "No such property"
    - "Out of memory"
    - "Print at illegal address"
    - "Stack overflow" [3]
    - "Stack underflow" [4]
    - "Store out of dynamic memory"
    - "Story file read error"
    - "Text buffer overflow"
    - "Unknown opcode"
    - "Unknown Z-code version"

    [1] The first byte of a routine must be less than 16.
    [2] In V4 and above, object numbers > 2000 are considered illegal.
    [3] Checked on every call instruction.
    [4] Checked on every return from a subroutine.

Acknowledgements:

    Many thanks to Paul D. Doherty for his continuing support of this
    project. Thanks to everyone who sent bug reports, contributions or
    helpful hints (in alphabetical order):

    Thomas Biskup, Ian Carpenter, Graeme Cree, Jason Dyer,
    Carl Edman, Julian Eggebrecht, Bernhard Fuchs, Joe Hachem,
    John Kennedy, Kirk Klobe, Marnix Klooster, John Mackin,
    Paul O'Brian, Magnus Olsson, Barry Prescott, L. Ross Raszewski,
    Ambat Sasi Nair, Alan Sherrod, Linards Ticmanis and Paolo Vece.

    Last but not least, thanks to the porters:

    David Kinder (Amiga), Rich Lawrence (Windows 95/NT),
    Andrew Holdsworth (RiscOS), Christos Dimitrakakis (HP-UX),
    Christopher J. Madsen (OS/2), Galen Hazelwood (Unix curses library),
    Ian Dean (Windows CE), Dave Griffith (current Unix maintainer).

    Executables are available from ftp.gmd.de and from

	http://www.geocities.com/SiliconValley/Heights/3222/frotz.html

    which is the Frotz home page maintained by Chris Madsen.
