Jaguar Development kit



At the last French Atari show in 1997 (Bercy, Paris), was done a little demonstration of a BOOTROM, able to start the jaguar console, and a board plugged in Jaguar , connected to a ST...The purpose was to show the first developement was working.

Atari Show, Paris, 1997, BOOTROM Demonstration with a Jaguar


The purpose of this project, is to give a hardware and sofwtare solution to uplaod any programs
designed for Jaguar and start them. Thus, this Kit use an alternate Eprom which replace the orginal Atari Jaguar ROM and a GEM software running with, I think, any Atari computer.
Currently, the hardware isn't ready, and so the communication beetween the Jaguar and your Atari will be done with the Joypad 2/Centroncis port (like BJL solution).

An ISA extension board will be used nextly as soon as possible, in order to get a nice transfer speed rate.

Because somes KIT already does exists, "previous" programs designed for Jaguar Server
or BJL should run with our new solution, while no specific kit features is used inside these programs.


Original Atari ROM is disabled by our EPROM, which contains JagOS, our own small operating monitor.

This one start the Jaguar and display a small "desktop" onto the monitor, and enter into a wait of command mode from the computer. JagOS allows especially to get a program and start it.

ABeside this basic function, JagOS support somes systems calls like TOS for instance, to give somes services to your programs Jaguar.



JagStudio is a full GEM application which permit you to communicate with the Jaguar.
Its main topic is send a program into the Jaguar memory and start this one.
Beside this purpose, you can dump the memorie, get the Eprom datas and receive messages
from JagOS or your applications, like a simple Debug string or a 68000 exception.

This program work with MagiC 5 or TOS.(Two specific release)


Automatic template source code generation. 

•Upload a Jag program and start i or upload any binaries datas to the Jaguar memorie. 

•Dump jaguar memorie. 

•Read and write Eprom data. 

•Handle 68000 jaguar exceptions. 

•Automatic recognition of data transfert asked by the Jaguar.

•Compress .CRY pictures to  .CCI format ( My own small picture compressed format, very easy). 

•Console window to display debug message.

•External editor and assembler (Like Devpac). 

•Help Buble and ST-Guide supported.

Technicals features: 

MagiC 5 prequired for the MagiC release

•TOS 1.02 and more for the TOS realease

•Written in C language

•Nice graphic user interface GEM (Modal and no modal windows, Popus menus on desktop and icon, toolbar) 

•English only language supported

•Longs filenames  (With  MagiC,). 


•AV_STARTPROG protocole

•BubbleGEM supported, with enable/disable

•ST-Guide aHelp format in english

•Enhancec INF configuratio file like Windows .INI

•ST-Guide Help files for JagOS andJToolBox. 



Jtoolbox is a programming librairy which contains all required code to drive the Jaguar. JagStudio is simply linked with it to use the Jaguar. Thus, you can use this one to realize your own JagStudio, or use the Jaguar inside another program whithout to need JagStudio.

Extension board

This board will be an ISA type extension and should be used with Milan or PC computers.  Not available currently, Sébastien is working on. 

Required configuration

•Atari  and compatibles

•1 Mo  free RAM at least, JagStudio use about  500 up to 700 Ko.

•IDE or SCSI harddisk 

•MagiC 5 Operating system or TOS 1.02 and more


The file content the followings elements:

  1. Aads-1.2.63 My homemade GEM library

  2. Official Jaguar Kit

  3. Projects Jaguar Kit

  4. Public with somes already ZIP files

  5. site.atari which contents the old Web Site with the Jaguar pages and hardware installation)


Jaguar Desktop Screen with JagOS V1.03

Jaguar Desktop Screen with JagOS V1.00

Laurent Favard, 2013