TOS, the Atari ST operating system on your Jaguar

(Based on The Jaguar Engine by bITmASTER, the original project-files may be found on the JDC Developer's CD)

GEM-Desktop of german TOS 1.2 with 2 drives and the tray

This screen shows the GEM-desktop of a german TOS 1.2.

bITmASTER told me, that using the expansion card he had built, he was able to develop on the Jaguar using the familiar PureC.

June 10, 2000: bITmASTER has implemented a mouse-emulation using joypad 1.

June 25, 2000: bITmASTER has implemented a driver for the LS120 SuperDisk drive.
This drive uses an ATAPI-port, and is capable not only to use it's own 120 MB-medium but normal 1.44 MB floppy-discs too (unlike the ZIP-drives).

August 9, 2000: Five prototype PCBs have been manufactured. Look at a picture of an almost complete populated PCB:
Picture of an prototype PCB
On the top edge, between the PS/2-type sockets for the keybord (the left one) and the mouse (the right one), resides the 40-pin IDE-connector.

August 14, 2000:
Here are two pictures of my development desk:
1. View of my desk 2. View of my desk
You can see the 640*400 monochrome GEM desktop (german TOS 2.06) with the "Open application"-dialog as part of a 640*480 pixel bitmap-object on the VGA-monitor screen. The small desktop-case from an old Tandon 286 PC contains the LS120 Superdisk-drive and supplies it with power. I'm using my BJL-equipped Jaguar, so i need the Joypad in Port 0 to enter the BJL-upload-routine, while
the white cable in Port 1 is the BJL-cable.
PS/2-type mouse and keyboard are attached, but didn't fit in these pictures.

How to connect a VGA-monitor to your Jaguar:
Jaguar Videoport VGA-15pin-HD-female plug
4B Red 1
7A Green 2
5A Blue 3
7B Luma Ground 6, 7
10B Video Ground 8, 10, 11
6A HSync 13
5B CompositeSync (usable as VSync) 14

Here is a sketch of the complete device:
It looks similar the Jaguar CD-attachment, but doesn't support the connection of another cartridge.
LS120-attachment LS120-attachment with Jaguar-like-shell

What happens on the screen when you have uploaded JAGTOS.JAG:

  1. First, you will see a blank white screen with the text " !  Jaguar-Booter V0.3  !"
  2. Then a RAM-disk is installed as drive A: and if this is done successful

  3. the text "RAM-Disk als Laufwerk A: installiert." appears on the screen
  4. At last GEM is started (For a short time the mousecursor will become a bee).
  5. Use joypad 1 to move the mouse-pointer and firebutton A to emulate clicks of the left mouse button.
  6. Use the PAUSE-button on the joypad to toggle between normal vertical size (only the upper half of the desktop will be visible) and half-vertical size (the complete desktop will be visible, but text will perhaps no longer be readable)

There are three archives available for this project: Because of the differences between the Jaguar and the Atari ST video hardware
(interleaved bits vs. interleaved bitplanes), only the hires-graphics mode of TOS is supported.
And because the JAGTOS.JAG sets the Jaguar's video system up for TV-sets,
only the upper half of the GEM desktop is visible. The DESKTOP.INF in the
TOS-image is patched, so that the paperbin is visible when starting.
Here is a picture of the 4layer-PCB:

4-layer PCB