Amiga Games Extra 1996 May/Amiga_Games_Extra_CD_5-96.bin/spiele/publicdomain/amclnt/doc/intro.txt

Text File | 1996-02-19 | 21KB | 402 lines

AmigaMUD, Copyright 1996 by Chris Gray


        Introduction to the AmigaMUD System

The AmigaMUD system is a software system for the Commodore Amiga line
of computers which implements a MUD (Multi-User-Dungeon). MUDs have
existed on various computers for about 20 years, usually run at
universities on networked computers. In a typical MUD, several people
connect to the system at the same time and interact by typing in
messages and commands to the MUD. MUDs are usually set up somewhat
like text adventures, in that they contain a small world in which the
players can explore, solve puzzles, etc. MUDs add to the adventure the
possibility of interaction, within the world, of the various players.
Players can talk to others in the same location; they can cooperate in
solving puzzles; they can compete in improving their characters or
personnas; they can engage in combat, etc.

The world in which the MUD is set is chosen and built by one or more
people who are the implementors or "wizards" or "gods" of the MUD. MUD
worlds have been set in various fictional as well as real situations,
such as Star Trek, Xanth, the Discworld, etc. Other MUDs specialize in
role playing, where the players pick a persona and do their best to
stay within it. For example, "furries" on FurryMUD all pick a furred
animal as their character.

Many MUDs exist on the 'internet', the international network of
computer systems, mostly supported by various governments. Amiga
computers are not often on this network, so they will usually get
their multiple players through serial ports and modems. Amiga-based
BBS systems often have multiple lines, and these can be used for
connections to AmigaMUD.

Today, most MUDs are strictly text based. That is, users do all
operations in the MUD by typing commands, and all output is via text
messages. In the last few of years, colour graphics have become
standard on home computers and workstations. MUDs are beginning to
take advantage of that capability by introducing simple graphics
output. Sound output is also possible.

AmigaMUD provides graphics and sound output as a standard element. It
also allows the use of the mouse and numeric keypad as input. The
system still provides the full text input and output interfaces,
however, and can be used in a text-only mode. The standard
availability of graphics output and mouse input can change the nature
of a MUD, and make it available to those who aren't terribly good at
typing, or who are uncomfortable with computers.


Basic Capabilities

The main function of the AmigaMUD system is to allow the playing of a
MUD, which is a multi-player text adventure game. As such, several
people can be playing the same game at the same time. There is no
inherent limit on the number of simultaneous players, but the CPU time
needed to handle the server and the serial port activity will likely
limit a top-end Amiga to under 50 active players.

The AmigaMUD system does word wrapping on output. This means that long
lines are automatically broken up on word boundaries. The designers of
the scenarios and the builders of new rooms and objects, etc. do not
have to worry about properly formatting things. The formatting is done
with respect to the actual output width of the MUD text window, which
varies depending on the amount of overscan the user has setup.

Graphics output is to a 320 pixel wide by 100 pixel high by 32 colour
graphics window at the top of the visible display (unless the user has
chosen to hide it). Primitives exist in the system to draw and fill
lines, circles, polygons, etc. A scenario can also scroll regions of
the graphics window, and can dump IFF ILBM graphics images (from the
machine on which the MUD client program is running) to the window.

The scenario can add "mouse buttons" to the graphics window. These are
small rectangular areas containing text that the user can click on
with the mouse. Doing so triggers an action in the scenario, such as
moving in a specific direction. The scenario can also set up regions
of the display which are sensitive to mouse clicks. Clicking within
such a region sends to the server a message indicating the position
within the region which was selected. This capability is used by the
icon editor in the standard scenario.

The MUD client program can use the Amiga's speech synthesizer software
(libs:translator.library and devs:narrator.device) to generate speech
output. This capability requires that libs:translator.library exist on
the server machine, and that devs:narrator.device exist on the client
machine. Note that these items are not currently shipped with versions
3.0 and up of the Amiga OS software package.

Scenarios can request that sound samples (IFF 8SVX files) be played on
client systems. Since the Amiga has four hardware sound channels, up
to four samples can be played simultaneously. These samples are loaded
from the AmigaMUD:Sounds directory on the client Amiga.

The MUD program supports the concept of icons. These are small (up to
16 x 16 pixels) one-bit-per-pixel images that are overlayed on top of
the main graphics imagery. They are used to indicate the presence, in
the same "room" as the player, of other players and NPCs.

The MUD program can "cache" local copies of descriptions of graphics
imagery, commands to play sounds, icons, etc. This caching can greatly
reduce the amount of data that must be continually retransmitted over
the serial connection, thus speeding up gameplay.

The MUD program includes a builtin full-screen text editor, which can
be used to edit room descriptions, object descriptions, etc. It can
also be used, when in wizard mode, to edit AmigaMUD functions, and is
integrated with the AmigaMUD programming language parser to show the
location of errors. MUD can also call out to an external editor for
these purposes.

The text adventure aspect of AmigaMUD includes a set of fairly
powerful routines to assist in writing code that "understands" pseudo-
English commands. For example, when the scenario is parsing a user
input line like:

  Put the apple, the pear and the black sword into the brown paper bag.

the code that understands how to put things into other things will be
automatically called three times, one for each object to be put into
the bag. Also provided are routines to aid in identifying the objects
being referenced.

The AmigaMUD system includes a fairly efficient interpreted
programming language which is used to build the scenarios or worlds
that run under the system. Note, however, that with the current
scenario, building of rooms, objects, etc. can be done entirely
without using any of this programming language. The language is a
strongly typed, structured language that should be usable by anyone
with a bit of programming experience. The entire scenario is built
using this language - rooms and objects are created dynamically by
executing code in the language. The standard scenario includes a large
set of utility routines designed to simplify the building of rooms,
etc. Here is an example AmigaMUD programming language routine, which
is a part of the standard scenario. It is used to draw the random
coloured rectangles which are the graphics imagery for the "SysAdmin's
Study" room:

    define tp_mall proc drawStudy()void:
    int i, x, y;

    for i from 1 upto Random(20) + 10 do
        GSetPen(nil, Random(32));
        x := Random(159);
        y := Random(99);
        GAMove(nil, x, y);
        GRectangle(nil, Random(160 - x), Random(100 - x), true);
    od;
    /* force a re-draw on look */
    Me()@p_MapGroup := UNKNOWN_MAP_GROUP;
    corp;

The standard scenario provided with AmigaMUD includes "builder
commands", which allow non-wizards to build new rooms and objects into
the scenario, while it is running. If the player is using the full MUD
client program, this building can be done using mouse-buttons and a
full-screen text editor.

The standard scenario also provides some functions which can draw a
simple overhead view of a room based on the obvious exits from that
room. Several styles are available, including pathways, tunnels, and
interior rooms. These simple graphics can be attached to rooms using
mouse-buttons. The colours used can be changed for variety.

If the Amiga running the server is also running UUCP software, the
standard scenario can provide MUD characters with access to usenet
news and email services. The ability to send news and email must be
explicitly enabled, however.

A fairly large combat area, similar in many ways to the areas used in
combat-oriented fantasy role-playing games, is present in the standard
scenario. This area includes most of the traditional elements in a
simplified form, and contains three of the six quests. This is the
largest region of the scenario.


The Components of the System

There are several pieces of the AmigaMUD system. Most of the pieces
are only needed on the central host or server system, however. A
remote system, if the user is satisfied with a text-only interface,
needs none of the AmigaMUD components. A terminal program to call up
the host system is sufficient. To get the full interface, however, the
following two components are needed:

    MUD - this is the main interface program. It provides the graphics
    and text output, the sound output, and the mouse and keypad
    input. It's use is described in detail in the 'MUD.txt'
    document in the AMClnt archive.

    mud.library - this is an Amiga OS shared library. It provides some
    of the functionality of the user interface that is also needed
    by the host/server system. To avoid needless duplication, that
    portion of the code is placed into the shared library, so that
    multiple users of it can use the same copy. This file must be
    copied into the system's 'libs:' directory.

The Amiga that is hosting the AmigaMUD system needs a couple more
programs, and can also use some minor utilities:

    MUDServ - this is the AmigaMUD server program. This is the main
    component of the system; it provides the world, or scenario,
    that the game takes place in, and provides the communication
    between the separate players. See the file 'MUDServ.txt' in
    the AMSrv archive more more details.

    MUDAgent - this program is the connection point between the server
    program and an external user. It communicates with a serial
    port on one end, and with Amiga OS messages to/from MUDServ on
    the other. There must be a copy of this program running for
    each currently active remote player. Local players can use
    'MUD' to connect directly to MUDServ. This program is
    documented fully in file 'MUDAgent.txt' in the AMSrv archive.

    AgentKill - this program is used to shut down copies of MUDAgent
    that were started from the Workbench. If MUDAgents are
    started from a shell, then use the shell 'status' command to
    find their CLI numbers, and the shell 'break' command to shut
    them down.

    SMUD - this is a simple text-only client program that normally
    runs on the same system as the server, and can be run only
    from a shell command line. It is useful for doing quick
    connections to the server since it uses much less memory than
    the full MUD client. It can also accept commands from
    redirected standard input. SMUD is described in file 'SMUD.
    txt' in the AMSrv archive. SMUD does packet-based DOS I/O, so
    it can also be used for remote text-only connections when
    called up by a BBS that is not capable of calling up the full
    MUDAgent interface.

    MUDCre - this program creates an empty AmigaMUD database in the
    current directory. Only those wishing to create an entire new
    scenario from scratch need to be concerned with this program.
    It is described in file 'MUDCre.txt' in the AMSrv archive.

    MUDFlush - this simple program sends a message to MUDServ asking
    that it flush out the database. The image of the database
    produced is complete and consistent, but only as of the
    instant it is produced. If machines are running, they can
    start changing the database as soon as the server is finished
    with the flush. Thus, it is always best to shut down the
    server before making a backup copy of the data files. MUDFlush
    can be used from the Workbench or from a shell.

    Note: this program is included only because it was previously
    included. You should use the scenario's new "backup" facility
    to do safe backups, or shut down the system before making a
    backup of the database files.

    MUDShut - this simple program sends a request to MUDServ asking
    that MUDServ shut down. MUDServ will do so as soon as there
    are no clients connected. MUDShut can be used from the
    Workbench or from a shell. When used from the shell, a "-w"
    flag can be given, in which case MUDShut will not terminate
    until MUDServ has fully shut down and notified MUDShut. This
    facility can be used to do automatic, externally driven
    backups of the database files.

    AmigaMUD: - this assign or volume name should be available when
    running AmigaMUD. The system looks for image and sound files
    under this location. If you do not have this name available,
    you will have to continually dismiss requesters asking for it.


How to Get AmigaMUD Up and Running Quickly

If you only want to get the system up and running to play with
locally, then it is quite easy:

    - copy mud.library to your libs: directory

    - pick a directory with enough space. Copy MUD.data and MUD.index
    to that directory. (These are the pre-built database files.)

    - start MUDServ in that directory. Use the 'run' command to put
    it in the background if you are using a shell.

    - start MUD with the -L flag or the LOCAL tooltype

    - login as SysAdmin, with password SysAdminPassword

    - explore away!


Some AmigaMUD Concepts

server, client - AmigaMUD uses the client-server mode of operation.
    MUDServ is a server; it responds to, or serves, requests for
    action coming from the various clients, which ultimately are the
    people playing the MUD. For example, when a player enters an input
    line in the MUD program, that line is packaged up as a message and
    sent to the server, MUDServ. MUDServ eventually gets around to
    looking at it (it may be busy doing other things), and will then
    process it according to the scenario, or world, that is being run.
    There may be many messages sent back to the client in response to
    the input line, such as several output lines of text, changes in
    the graphics display, sound output, etc. The reverse situation
    never happens - the server never waits for responses from clients,
    since doing so might get it stuck forever. (Actually, the client
    does not wait for a response on an input line message, but it does
    for a variety of other types of messages.)

scenario - the scenario that AmigaMUD is running is governed by the
    contents of the database files. They contain all of the text
    strings and AmigaMUD functions that define the world. In the
    standard scenario, the world contains the minimall area, the
    streets of the town, the builder's guild, the proving grounds,
    etc. Other scenarios are possible, which could have completely
    different layout, different rules, different commands, etc. Other
    MUD systems use names like 'mudlib' for the scenario.

wizard - when most players connect to AmigaMUD, they will see an
    'input> ' prompt and will type scenario commands like "north",
    "take the apple", etc. In this mode of operation, the input
    commands are being interpreted by the scenario. If a player is
    designated as a wizard, however (which can only be done by another
    wizard), then it is possible for the player to go into "wizard
    mode". In this mode of operation, input lines are interpreted
    directly by the AmigaMUD programming language. Normally, the
    prompt changes to '> ' in this mode. For example, a wizard could
    enter a line reading '2 + 2.', and the system would respond with
    '==> 4' - it has parsed the input line into a small function,
    executed the function, and printed the result. Consult the file
    "Programming.txt" in the AMDoc archive for more information on
    wizard mode.

apprentice - an apprentice is something like a partial wizard. They
    can use the programming language like wizards, but must operate
    under certain restrictions.

builtin - much of the standard scenario is functions written in the
    AmigaMUD programming language. These functions are interpreted by
    MUDServ as needed. MUDServ itself provides a number of predefined
    functions, which are executed directly, rather than being
    interpreted. These are called 'builtin' functions. An example is
    the 'Print' builtin, which takes a string expression as its
    argument and prints that string to the text window of the
    currently active client. (It is actually quite a bit more
    complicated than that, but the result is the same.)

bi-directional asynchronous reliable protocol - this mouthfull
    describes the way in which the MUD remote client program and the
    MUDAgent host program communicate. A protocol is just a set of
    rules which govern communication. The protocol, which runs over
    a serial (and usually modem) connection, allows messages to go in
    both directions (client to server and server to client). The
    protocol is asynchronous in that either end can send a message
    whenever it wants, without getting agreement from the other end.
    The protocol is reliable in that each message has a CRC (Cyclic
    Redundancy Check) which allows a receiver to check that the
    message hasn't been mangled during transmission. If it has, the
    receiver tells this to the sender, and the sender will resend the
    message. This continues until it is received correctly, or until
    one of the ends gives up entirely, and terminates the connection.

machine - many modern adventure games have characters other than the
    player who are wandering around in the world. Often, the player
    can interact with these characters. In the role-playing world,
    these other characters are called NPC's (Non-Player Characters).
    Many MUDs have a similar capability. In AmigaMUD, "machines" are
    used to implement NPC's. Machines are much like player characters
    except that they are governed by AmigaMUD programs, instead of by
    a person. Other MUDs call them robots, or bots, or just NPC's.

quest - usually, adventure games have a definite final goal or
    solution. Having a single solvable puzzle in a MUD usually doesn't
    work very well, since the first character to solve the puzzle can
    render it pointless for the rest of the characters. This is
    realistic, but can make for a dull game. Instead, many MUDs have
    quests, which are smaller puzzles which can be solved over and
    over again, although usually only once per character. A similar
    situation occurs with special objects, such as powerful weapons.
    There will usually be a supply of them, although larger scenarios
    can have a small selection of special objects which are unique.

security - security can mean a variety of things in a MUD. The
    simplest meaning is that there be no ways, within the game, for
    cheating on the quests or for gaining power or influence without
    doing so in the "proper" fashion. Problems of these kinds are
    normally just bugs or oversights in the scenario. At the other end
    of the scale are ways by which wizards, remotely connected to the
    MUD, can access or damage the host computer running the MUD. This
    kind of problem is much more severe, and usually arises from bugs
    or oversights in the MUD system itself. In between these two
    extremes are issues such as wizards using their wizard abilities
    to mess up quests and areas built by other wizards.

SysAdmin - all AmigaMUD databases contain a SysAdmin character. This
    character is the "god" of AmigaMUD. It can do anything in the MUD
    and can see anything. SysAdmin can even look into the private
    symbol tables of other wizards. Certain of the builtin functions,
    such as the ones which write to disk, can be executed only by
    functions owned by SysAdmin. Because of this power, the standard
    password for SysAdmin should be changed for any MUD which is made
    available to other players, and the new password should be guarded
    carefully. As shipped, AmigaMUD will not allow SysAdmin to log in
    remotely unless special action is taken to enable it. SysAdmin is
    intended to be used only by the system administrator of the server
    system. If any routines which use some of the dangerous functions
    are written or changed, SysAdmin should be very careful that he
    has not created a way for others to mess up his computer.