2.8 Version differences
by Lance Ewing
<be@ihug.co.nz>
Last updated: 27 January 1998
There are a number of different versions of the AGI interpeter
but generally the data formats are the same or can easy be
converted between each other. The following table is a list of
AGI interpreter versions that I know of:
AGI
Version |
Interpreter
File Size |
AGIDATA.OVL
Size |
Number of
Commands |
OBJECT File
Encrypted |
LZW Used In
VOL Files |
| 2.089 |
34305 |
6656 |
155 |
No |
No |
| 2.272 |
34816 |
6656 |
161 |
No |
No |
| 2.411 |
38400 |
7680 |
169 |
Yes |
No |
| 2.435 |
38400 |
7680 |
169 |
Yes |
No |
| 2.439 |
38400 |
7680 |
169 |
Yes |
No |
| 2.440 |
38400 |
7680 |
169 |
Yes |
No |
| 2.915 |
39424 |
8192 |
173 |
Yes |
No |
| 2.917 |
39424 |
8192 |
173 |
Yes |
No |
| 2.936 |
39424 |
8192 |
175 |
Yes |
No |
| 3.002.086 |
40866 |
8064 |
177 |
Yes |
Yes |
| 3.002.098 |
40898 |
8080 |
181 |
Yes |
Yes |
| 3.002.102 |
40898 |
8080 |
181 |
Yes |
Yes |
| 3.002.107 |
40962 |
8080 |
181 |
Yes |
Yes |
| 3.002.149 |
40520 |
7488 |
181 |
Yes |
Yes |
This table illustrates a number of things.
- Firstly, as the interpreter version increased, the number
of AGI commands supported increased with it. The last
eleven we do not know the names of.
- There are two main AGI versions: AGI v2 and AGI v3.
- The early AGI v2 games did not encrypt the OBJECT file
with the "Avis Durgan" string.
- AGI v3 games use adaptive LZW to compress their LOGIC,
VIEW, and SOUND files.
COMMAND ARGUMENT NUMBER DESCREPENCIES
There are four commands that have changed the number of
arguments that are passed to them. All this information is based
on observations made of the above interpreter versions.
- (i) The quit command had no arguments for version 2.089
whereas all the others above have one argument.
- (ii) The print.at and print.at.v commands had only three
arguments for versions 2.089 - 2.400 and four for the
other versions.
- (iii) Unknown command number 176 had one argument for
version 3.002.086 but later versions had no arguments for
this command.
AGI VERSION THREE
There are a number of other differences between AGI v3 and AGI
v2.
- The LOGIC files do not encrypt the text messages with
"Avis Durgan" since there is no need to do this
because it is compressed anyway.
- The PICTURE file format is slightly different for picture
codes 0xF0 and 0xF2, i.e. the codes that change the
visual colour and priority colour. The difference is that
only 4-bits are used to store the colour as opposed to
8-bits in AGI v2.
NUMBER OF STRINGS
There may be some differences in the number of strings
supported by some interpreters as well. All interpreters have at
least 12 strings. Most interpreters have space for 24 strings but
I don't know if the extra space is used for strings or not.
