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. <>