Amiga Games: Greatest Hits 1996/Amiga Games: Greatest Hits 1996.iso/spiele/publicdomain/scott/docs/definit.txt

Text File | 1996-07-29 | 6KB | 143 lines

Game

A game consists of a header of 14 values each apparently 16 bit

0       Unknown
1       Number of items
2       Number of actions
3       Number of Nouns and Verbs (one list is padded)
4       Number of rooms
5       Maximum a player can carry
6       Starting Room
7       Total Treasures (*)
8       Word Length (only seen 3,4 or 5)
9       Time light source lasts. This counts down every time item 9 is
        in game. Brian Howarths games allow -1 for never run down. When
        it runs out the light item (9) is dumped in room 0 and a look
        done. Messages vary between interpreters and include things
        like 'Your light is flickering and dying' as well as
        'Light runs out in %d turns'.
10      Number of Messages
11      Room you must put treasure in to score points. Not all games use
        the treasure system for scoring
12      Unknown

All the number of something values are the last item to be read counting
from 0. Thus 3 messages, means messages 0, 1, 2 and 3.

(*) This can be calculated in game. What happens if the number is wrong
I don't know. I've found no games that it occurs in.

A game has 16 (maybe more) binary flags, and 8 (maybe more counters). A few
later games seem to have 2 (maybe more) values to store location numbers in
temporarily - eg Yoho spell in Claymorgue.

Following the header is a list of game actions. Each is of the form

150*verb+noun
5 repeats of condition+20*value
150*action1+action2
150*action3+action4

Conditions

0       Parameter
1       Item <arg> carried
2       Item <arg> in room with player
3       Item <arg> carried or in room with player
4       In room <arg>
5       Item <arg> not in room with player
6       Item <arg> not carried
7       Not in room <arg>
8       BitFlag <arg> is set.
9       BitFlag <arg> is cleared
10      Something carried       (arg unused)
11      Nothing carried         (arg unused)
12      Item <arg> not carried nor in room with player
13      Item <arg> is in game           [not in room 0]
14      Item <arg> is not in game       [in room 0]
15      CurrentCounter <= <arg>
16      CurrentCounter >= <arg>
17      Object still in initial room
18      Object not in initial room
19      CurrentCounter = <arg>

Actions

0       Does nothing
1-51    Print message 0-50. Some drivers add a space some add a newline.
52      Get item <arg>. Checks if you can carry it first
53      Drops item <arg>
54      Moves to room <arg>
55      Item <arg> is removed from the game (put in room 0)
56      The darkness flag is set
57      The darkness flag is cleared
58      Bitflag <arg> is set
59      The same as 55 (it seems - I'm cautious about this)
60      BitFlag <arg> is cleared
61      Death. Dark flag cleared, player moved to last room
62      Item <arg> put in room <arg>
63      Game over.
64      Describe room
65      Score
66      Inventory
67      BitFlag 0 is set
68      BitFlag 0 is cleared
69      Refill lamp (?)
70      Screen is cleared. This varies by driver from no effect upwards
71      Saves the game. Choices of filename etc depend on the driver alone.
72      Swap item <arg1> and item <arg2> locations
73      Continue with next line (the next line starts verb 0 noun 0)
74      Take item <arg> - no check is done too see if it can be carried.
75      Put item <arg1> with item <arg2> - Not certain seems to do this
        from examination of Claymorgue
76      Look (same as 64 ?? - check)
77      Decrement current counter. Will not go below 0
78      Print current counter value. Some drivers only cope with 0-99
        apparently
79      Set current counter value
80      Swap location with current location-swap flag
81      Select a counter. Current counter is swapped with backup counter
        <arg>
82      Add <arg> to current counter
83      Subtract <arg> from current counter
84      Echo noun player typed without CR
85      Echo the noun the player typed
86      CR
87      Swap current location value with backup location-swap value <arg>
88      Wait 2 seconds
89      SAGA - draw picture <n> (actually <n+number of rooms>, as each
        Look() draws picture <room number> automatically)
        Older spectrum driver - crashes
        Spectrum Seas of Blood - seems to start Fighting Fantasy combat mode
90-101  Unused
102+    Print message 51-99


This is followed by the words with verbs and nouns interleaved. A word with
a * at the beginning is a synonym for the word above.
Verb 1 is GO, verb 10 is GET, verb 18 is DROP (always).
Nouns 1-6 are directions.

This is followed by the rooms. Each room is 6 exits (north south east west
up down) followed by a text string.

Then come the messages, stored as a list of strings.

Next come the items in the format item text then location. Item text may
end with /TEXT/. This text is not printed but means that an automatic
get/drop will be done for 'GET/DROP TEXT' on this item. Item names beginning
with '*' are treasures. The '*' is printed. If you put all treasures in the
treasure room (in the header) and 'SCORE' the game finishes with a well done
message. Item location -1 is the inventory (255 on C64 and Spectrum tape
games) and 0 means not in play in every game I've looked at. The lamp (always
object 9) behaviour supports this belief.

A set of strings follow this. In order they match to each line of verb/noun
actions, and are comments. The Spectrum and C64 tape system where the
database is compiled into the program has no comments.

Finally three values follow which are version, adventure number and an
unknown magic number.