Voila, j'ai un fichier .jam qui contient des données qui m'interessent.
Malheuresement, je ne trouve pas de programme qui me permette de traiter ce genre de fichier.
 
Si quelqu'un peut m'aider...
 
Merci d'avance!!

Ca ressemble fortement à une image à ouvrir avec Roxio Jam, un soft de gravure pour Mac ...

regarde là éventuellement
http://www.filext.com/detaillist.p [...] mit3=Go%21

il semblerait que cela soit une image Microprose (la societe de jeux video). Mias rien concernant comment l'ouvrir!!

hi hi t'as trouvé où ton fichier ? regarde avec XnView, il ouvre quasiment tout...

En fait c'est un fichier d'un jeu, qui contient de jolis ecrans de chargement! mais impossible d'avoir ces screens autres part.
 
La j'ai un loadscrn.jam, je pense qu'ils sont dedans!
 
Sinon impossible de l'ouvrir avec XN'View!

il fait quelle taille ton fichier ?
ouvre le avec un truc genre textpad pour voir la structure... ou alors avec RessourceHacker voir si il trouve qqch

mon fichier pese 86mo!!
 
Impossible de l'ouvrir avec ResHacker et voila le resultatavec textpad:
 

J'ai vu aussi que c'était une extension java pour les portables .

j'avais vu ca aussi hier, mais j'pense po que ca ait un rapport!

hm... je ne sais pas trop...

t'as lu çà http://ourworld.compuserve.com/hom [...] ay/gp2.htm

C'est quand meme dommage, ils font de beaux screens, mais ils ne les mettent po dispo, ni te donne un moyen d'y accede (mis a prt ds le jeu)!

ca sent bon ce que tu m'as donne wonee!! j'essaie de suite!!

par contre, desolé mais je comprend po trop comment ca marche! voila ce que me dit le .txt:
 
     GP2JAM - Grand Prix 2 JAM to BMP Converter
   Copyright (c) 1996 Trevor Kellaway (100331.2330@compuserve.com)
 
         V2.0 28th Sep 1996
 
Please read this file as it contains lots of useful tips. Make sure you read
it before sending me any E-mail questions!
 
If you have a web browser why not have a look at the GP2JAM.HTM contained in
this distribution rather than this dull ASCII file!
 
Introduction
------------
Grand Prix 2 (GP2) from Microprose stores its image files in a unique format,
these files have the extension '.JAM' (referred to as 'JAM' files).
 
GP2JAM is a DOS program which converts GP2 JAM files to .BMP files and back
again. You will find these images in the X:\GP2\GAMEJAMS\ directory and sub-
directories on your hard disk (or CD-ROM drive), where X: is the drive letter
where you installed the game or your CD-ROM drive letter.
 
GP2JAM supports virtually all the JAM files (~200!). For example you can
convert from a WILLIAMS.JAM file to a WILLIAMS.BMP. You can now use your
favourite bitmap editor to modify the image and save it. Next you would
convert the WILLIAMS.BMP back to WILLIAMS.JAM.
 
Note: You must have installed GP2 in either Medium or Full install mode for
the modified JAM files to appear in the game. Minimum install mode will not
work (even though it does actually copy the JAM files to your hard disk it
doesn't seem to read them!).
 
Installation
------------
This distribution should include the following files:
 
 GP2JAM.TXT A text version of the help file.
 GP2JAM.HTM An HTML version of the help file.
 GP2JAM.EXE The converter program.
 32RTM.EXE    32-bit DOS extender (not reqd. for WFW/W95/NT), only DOS.
 DPMI32VM.OVL 32-bit DOS extender (not reqd. for WFW/W95/NT), only DOS.
 
Copy GP2JAM.EXE to any directory on your hard disk, I recommend that you
create a new directory (say 'C:\JAM'), you can then keep all your updated JAMs
and BMPs there without cluttering up the game directories (this also allows
you to reinstall the game without losing your images). If you are running
under straight DOS (not WFW/W95/NT) then you will need to copy 32RTM.EXE and
DPMI32VM.OVL to the same directory as GP2JAM.EXE.
 
Quick Start
-----------
Here is a quick tutorial on how to start painting the Williams.
 
Change directory to where you put GP2JAM.EXE ('C:\JAM'). Convert the Williams
JAM file to a bitmap by typing the following at a DOS command prompt:
 
 GP2JAM -jC:\GP2\GAMEJAMS\WILLIAMS.JAM
 
This should create a WILLIAMS.BMP in the current directory (Note: If the game
is stored on a different drive then add the appropriate drive letter at the
front of the filename).
 
Now startup your favourite bitmap editor (Paint Shop Pro is a good one, much
better than Windows/W95 Paintbrush) and load the WILLIAMS.BMP. You should see
a picture of the different panels of the car. Paint the car and then save
the WILLIAMS.BMP again.
 
Now back at the DOS prompt convert the file back to a JAM:
 
 GP2JAM -bWILLIAMS.BMP -jC:\GP2\GAMEJAMS\WILLIAMS.JAM
 
That should be it. Startup GP2 and admire your work!
 
Important
---------
All of the JAM files have a unique identity (ID) encoded in them so you can't
copy a WILLIAMS.JAM over the top of say a BENETTON.JAM, you will get a
transparent (invisible) car! GP2JAM will always display the actual JAM ID when
converting to help you identify which file you are manipulating, this only
becomes useful if you start renaming the JAM files in your directory (don't
rename the games JAM files!).
 
Usage
-----
GP2JAM [-h?v] [-y] [-bFILENAME.BMP] [-jFILENAME.JAM]
 
     -h|-?         Display this usage message.
     -v            Display the version number & contact information.
     -i            Display information about conversion process.
 
     -jFNAME.JAM Set the JAM filename to be 'FNAME.JAM'.
     -bFNAME.BMP Set the BMP filename to be 'FNAME.BMP'.
 
     -y            Automatically answer all questions with 'Yes'.
 
When converting from a JAM to BMP you need only specify the JAM filename:
 
 GP2JAM -jWILLIAMS.JAM
 
This will automatically create a WILLIAMS.BMP (based on the JAM ID), if the
WILLIAMS.BMP file already exists you will be asked if you wish to overwrite
it. You can turn off these prompts by using the '-y' option which will
automatically respond 'Yes' to all prompts.
 
If you wanted to use a different bitmap filename specify it after the JAM
filename:
 
 GP2JAM -jC:\GP2\GAMEJAMS\WILLIAMS.JAM -bCAR1.BMP
 
To convert back from a BMP to a JAM file you must specify both filenames and
the BMP filename must be first:
 
 GP2JAM -bWILLIAMS.BMP -jC:\GP2\GAMEJAMS\WILLIAMS.JAM -y
 
This will update the existing WILLIAMS.JAM file (Note: the '-y' option was
present to automatically respond to the overwrite prompt).
 
Note: The destination JAM file *must* already exist, GP2JAM only updates the
original JAM file from BMP, it never actually creates the JAM file.
 
You can display the usage message by starting GP2JAM either with no command
line options, or use either '-?', or '-h'.
 
To find out which version of GP2JAM you have use the '-v' option, this also
displays the author's E-mail address and web site URL.
 
You can obtain a list of the all the JAM files supported by GP2JAM by using
the '-f' option.
 
Bitmaps and Palettes
--------------------
When you first convert an original game JAM file GP2JAM may display the
following warning:
 
 'Warning: The image contains unique colours which can't be mapped to GP2JAM's
 standard palette, these will be mapped to the nearest colour available.'
 
Don't worry about this, GP2JAM uses a different fixed palette to that of the
images in the game and maps the game colours to the nearest available ones in
its palette. When you perform a later update of an image you've edited
previously you won't get this warning.
 
When saving the BMP image don't change the colour depth (256) or change the
image size.
 
You can use any of the colours from the fixed palette but *don't* change the
palette as this is fixed by the game and the BMP just contains a copy
(changing the palette won't have any effect in the game). Make sure you save
the bitmap RGB encoded (not RLE or OS/2 encoded).
 
Don't over paint the background (dull green) colour or move any of the image
parts. A good way to paint large areas is to use the selective colour eraser
tool which is available in most good painting packages.
 
Car Images
----------
For the cars the BMP has several small rectangles which are all one colour,
these are the suspension arms. The car images also have a graduated set of
rectangles in the top left hand side of the images, don't modify these as they
are used to shade the car tyres when the car is viewed from a far distance.
 
In the game some cars have high noses and some low noses, this information is
hard coded within GP2.EXE and not in the JAM files so you can't modify this
(I'll write a utility for this later). The internal cockpit colours (when viewed
from the driving position) are also hard coded in GP2.EXE. A utility for
modifying the cockpit colours is meant to be available on the Web but I
haven't checked it out.
 
The car numbers displayed in the game text screens (rather than the ones on
the cars) also are hard coded within GP2.EXE, again a utility to modify these
is available on the Web.
 
Note: When painting the car numbers you will notice there are two copies for
both the front and rear wings. You must ensure that you place a copy of the
lower number actually on the car as well as GP2 when it is running sometimes
will use the image painted on the car rather than over paint it with the copy.
 
Helmets
-------
The helmets are all stored in one file called HELMETS1.JAM. You will need to
use the zoom option of you paint program as each helmet image is fairly small.
Note: Don't paint over the graduated colours on the far left of the image,
these are used to colour the helmet when it is viewed from a far distance.
 
Adverts / Billboards
--------------------
There are two main files which contain the adverts, ADVERTS1.JAM and
ADVERTS2.JAM. Each of these files contains a number of sub-images for
different adverts. The game uses a fixed method of displaying these adverts at
each track. The two files above are used at all the tracks, in addition to
these though each track sub-directory (of \GP2\GAMEJAMS, e.g., PORJAMS for
Portugal) has a file like POR_AD1.JAM (look for the _AD1 in the name) and
these contain track specific images.
 
Special Images - E.g., Pit Crew
-------------------------------
There are a number of special images which appear to be painted in strange
colours, the pit crew for instance.
 
A good example is the flag marshall images (FLAGS1.JAM, FLAGCHEQ.JAM), these
all appear to have a blue flag. When the game runs it knows about this range
of blue palette entries and maps these to the desired colour, normally this
will be yellow or green for use when a crash occurs. You *must* not change
these special colours, you can paint other parts of the image though you
shouldn't use the special colour (blue in this case) anywhere on the image as
this will also change colour!
 
The pit crew are another special case. These are almost all totally updated by
the game when it runs from fixed colours hard coded in GP2.EXE. I'm sure a
utility to update these colours in GP2.EXE will be released at some stage.
 
Circuit Specific Images
-----------------------
Within the \GP2\GAMEJAMS directory there are is a sub-directory for each
track, within these directories are circuit specific images which include
adverts, buildings and scenery. Be careful not to mix these files up with
those in the main directory or another track sub-directory as many of these
have duplicate names.
 
Known Problems
--------------
GP2JAM has been tested with the European GP2 V1.0b and works fine in VGA and
SVGA.
 
There are a few JAM image filenames which GP2JAM can't uniquely identify, it
will display these as "????????".
 
GP2JAM doesn't support the RCR*.JAM files, these are only images of cars and
wouldn't be suitable for modifying anyway.
 
Pre-painted Car Sets / Images
-----------------------------
Please *don't* send me the results of your painting, I'll get swamped with
file E-mails otherwise! I won't be producing any car sets (I just write the
converter, I never actually use it!), but some good ones are available on the
web.
 
Checkout Dave Gymer's web site:
 
     http://www.gamesdomain.co.uk/dgymer/f1gp/
     ftp://www.gamesdomain.co.uk/pub/users/dgymer/f1gp/
 
Another good site is Pieter's Grand Prix 2 Home Page:
 
 http://cervino.vol.it/GP2/
 
Note: The JAM files don't compress at all, so if possible when creating a car
set include the BMP files as they do compress (I recommend you create a
JAMS.ZIP and a BMP.ZIP then the downloader can choose which one to download,
the BMP.ZIP will be much smaller than the JAMS.ZIP).
 
History
-------
V1.0 18th Aug 1996 Initial version.
    Only supports car JAM files.
V2.0 28th Sep 1996 All JAM files now supported.
 
E-mail / Further Info
---------------------
Please send any suggestions, comments, or bug reports (include the version of
GP2JAM you are using and your Operating System details [DOS,WFW,W95,O/S2,NT])
to the author Trevor Kellaway at:
 
CompuServe:    [100331,2330]
Internet:      100331.2330@compuserve.com
 
The current version of GP2JAM will always be available on my web page along
with the current version of this help file.
 
 http://ourworld.compuserve.com/homepages/tkellaway/
 
It should also be available on CompuServe in GO SPRTSIMS, Lib #14 (Racing
Circuits) as GP2JAM.ZIP.
 
This program may be freely copied and distributed, as long as it is not
modified in any way, no fee is charged and this file is always included. This
program is provided "as is" with no warranties expressed or implied. The
author will not be held responsible for any losses incurred, either directly
or indirectly by the use of this program.
 
This is *not* an Microprose product. If you have problems with the game then
try it without using this program.
 
The author has no connection with Geoff Crammond or Microprose.
 
<<End of document>>

ok c'est tout simple, si t'as ce programme, balance tous les fichiers dans un rép genre c:\temp\ y compris ton fichier JAM
 
après avec une commande dos (démarrer executer cmd.exe) tu vas dans c:\temp et tu tappe :  
GP2JAM -j mon_fichier.jam et ça doit y décompresser...

bon sinon j'ai trouve plein de tit soft pour convertir des .jam en .bmp mais malheuresement ils ont ete construit pour GP2 et s'utilise avec le .exe gp2! donc si quelqu'un arrive a me decrire la procedure pour le dos, c'est ma derniere solution...

Eux attention j'ai juste filer ce lien mon montrer qu'il ya vait comme par ex pour GP1 et GP2 des outis de conversions JAM vers BMP. Chu pas sur que çà fonctionne pour autres choses que les jam de GP

je test darxmurf...

hum en fait le -j et le nom du fichier doivent être collé on dirait...
GP2JAM -jMon_fichier.jam

merde, il me dit que mon fichier est trop gros: "the filesize of LoadScrn.jam is not Supported"!

regarde éventuellement là http://www.fortunecity.com/underwo [...] bnutil.htm

le seul bon prog proposé est gp2jam, que j'ai deja test sans reussite!!

hum... réinstall le jeux et prends des photos

ben jvois qu'on a tt essaie, plus d'autre soluce!!!
 
En tout cas merci a tt ceux qui on tente de trouve la solution!!
 
A++