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JAGUAR

JAGUAR 64-Bit Interactive Multimedia System !!!

Logo animé

* Sommaire :

*  Caractéristiques techniques :

(Je ne me souviens plus où j'ai trouvé ce texte.)

Size: 9.5" x 10" x 2.5"
Controls: Power on/off
Display: Programmable screen resolution.
Horizontal resolution is dependent on the amount of scanline buffer space given to the "Tom" graphics processor.
Maximum vertical resolution varies according to the refresh rate (NTSC or PAL). Reportedly, a stock Jaguar (without additional memory) running NTSC can display up to 576 rows of pixels.
24-bit "True Color" display with 16,777,216 colors simultaneously (additional 8 bits of supplimental graphics data support possible)
Multiple-resolution, multiple-color depth objects (monochrome, 2-bit, 4-bit, 8-bit, 16-bit, 24-bit) can be used simultaneously
Ports: Cartridge slot/expansion port (32 bits)
RF video output
Video edge connector (video/audio output) (supports NTSC and PAL; provides S-Video, Composite, RGB outputs, accessible by optional add-on connector)
Two controller ports
Digital Signal Processor port (includes high-speed synchronous serial input/output)
Controllers: Eight-directional joypad
Size 6.25" x 5" x 1.6", cord 7 feet
Three fire buttons (A, B, C) or Six buttons (A, B, C, x ,y, z)
Pause and Option buttons
12-key keypad (accepts game-specific overlays)
The Jaguar has five processors which are contained in three chips. Two of the chips are proprietary designs, nicknamed "Tom" and "Jerry". The third chip is a standard Motorola 68000, and used as a coprocessor. Tom and Jerry are built using an 0.5 micron silicon process. With proper programming, all five processors can run in parallel.
  • "Tom"
    • 750,000 transistors, 208 pins
    • Graphics Processing Unit (processor #1)
      • 32-bit RISC architecture (32/64 processor)
        • 64 registers of 32 bits wide
        • Has access to all 64 bits of the system bus
        • Can read 64 bits of data in one instruction
      • Rated at 26.591 MIPS (million instructions per second)
      • Runs at 26.591 MHz
      • 4K bytes of zero wait-state internal SRAM
      • Performs a wide range of high-speed graphic effects
      • Programmable
    • Object processor (processor #2)
      • 64-bit RISC architecture
      • 64-bit wide registers
      • Programmable processor that can act as a variety of different video architectures, such as a sprite engine, a pixel-mapped display, a character-mapped system, and others.
    • Blitter (processor #3)
      • 64-bit RISC architecture
      • 64-bit wide registers
      • Performs high-speed logical operations
      • Hardware support for Z-buffering and Gouraud shading
    • DRAM memory controller
      • 64 bits
      • Accesses the DRAM directly
  • "Jerry"
    • 600,000 transistors, 144 pins
    • Digital Signal Processor (processor #4)
      • 32 bits (32-bit registers)
      • Rated at 26.6 MIPS (million instructions per second)
      • Runs at 26.6 MHz
      • Same RISC core as the Graphics Processing Unit
        • Not limited to sound generation
      • 8K bytes of zero wait-state internal SRAM
      • CD-quality sound (16-bit stereo)
        • Number of sound channels limited by software
        • Two DACs (stereo) convert digital data to analog sound signals
      • Full stereo capabilities
      • Wavetable synthesis, FM synthesis, FM Sample synthesis, and AM synthesis
    • A clock control block, incorporating timers, and a UART
    • Joystick control
  • Motorola 68000 (processor #5)
    • Runs at 13.295MHz
    • General purpose control processor
Communication is performed with a high speed 64-bit data bus, rated at 106.364 megabytes/second. The 68000 is only able to access 16 bits of this bus at a time.

The Jaguar contains two megabytes (16 megabits) of fast page-mode DRAM, in four chips with 512 K each. Game cartridges can support up to six megabytes (48 megabits) of information, and can contain an EEPROM (electrically erasable/programmable read-only memory) chip to save game information and settings. Up to 100,000 writes can be performed with the EEPROM; after that, future writes may not be saved (performance varies widely, but 100,000 is a guaranteed minimum). Depending on use, this limit should take from 10 to 50 years to reach.

The Jaguar uses 24-bit addressing, and is reportedly capable of accessing data as follows:
  • Six megabytes cartridge ROM
  • Eight megabytes DRAM
  • Two megabytes miscellaneous/expansion

All of the processors can access the main DRAM memory area directly. The Digital Signal Processor and the Graphics Processor can execute code out of either their internal caches, or out of main memory. The only limitations are that
  1. "jump" instructions in main memory have certain restrictions; the JMP (unconditional jump) command is longword-aligned, while the JR (jump-indexed-by-register) command must be either word- or longword- aligned.
    And
  2. running out of the cache is much faster (up to four times faster) and efficient.
Some believe that the inability to jump/branch in main memory makes the main memory feature useless.
Swapping data between the caches and the main memory is a quick, low overhead operation, and therefore the main memory is often used as "swap space" for cache code. The RISC compiler included in the latest Jaguar developer's kit produced code that transparently swaps code through the cache. This effectively allowed developers write RISC code without concern for the cache size limits.

Compressed cartridge data can be uncompressed in real-time, and ratios of up to 14:1 have been cited. In theory, a Jaguar cartridge can store up to 84 megabytes (672 megabits) of data, though actual results will vary widely (most often, images are compressed, while sound and code are not). Compression is performed with BPEG, an enhanced JPEG image decompression mechanism. BPEG supercedes the former JagPEG algorithm, working up to 10 times faster and with more flexibility.
Other Jaguar features:
  • Support for ComLynx I/O for communications with the Atari Lynx hand-held game system and networked multiconsole games (on DSP port, accessible by optional add-on connector). Networking of up to 32 Jaguar units available.
  • The two controller ports can be expanded to support "dozens" of controllers
    • Digital and analog interfaces
    • Keyboards, mice, and light guns are possible
  • Expansion port allows connection to cable TV and other networks
  • Digital Signal Processor port allows connection to modems and digital audio peripherals (such as DAT players)
  • One megabyte per second serial interface
  • 9600 baud, RS-232 serial port (accessible with optional interface)
  • General-purpose I/O bits via the cartridge port
  • Can accomodate future expansions of different processor types, I/O types, video types, and memory types and/or quantities.

*  Effets Visuels :

The Jaguar was capable of doing the following visual effects:

- High-speed scrolling (Object Processor).
- Texture mapping on two- and three-dimensional objects (GPU and Blitter).
- Morphing one object into another object (GPU).
- Scaling, rotation, distortion, and skewing of sprites and images (Object Processor).
- Lighting and shading from single and multiple light sources (GPU and Blitter).
- Transparency (Object Processor).
- "Rendering" up to 850 million one-bit pixels/second (35 million 24-bit pixels/second, 26 million 32-bit pixels/second), or 50 million Goroud shaded pixels/second. "Rendering" is believed to mean transferring a pixel from a frame buffer to the screen.
- Sprites of "unlimited" size and quantity. Realistically, sprites can be over 1,000 pixels wide/tall, and the number of sprites allowed is limited by processor cycles instead of a fixed value in hardware (Object processor).
- Programmable screen resolutions, from 160 to 800 pixels per line. The resolution can be increased even further with additional hardware up to a reported 1350 pixels per line.

One of the Jaguar modes is called "CRY mode", which supports lighting and effects in 3D graphics. Red, green, and blue color elements are ranged from 0 to 255, and the lighting level for any pixel can be changed by setting one byte linearly. E.g., the relative proportions of red, blue, and green are indicated with one byte, while a second byte selects an overall intensity of 0 to 255. CRY allows much smoother shading of single colors, but doesn't allow blending between colors as smoothly.

Actual graphics performance is hard to measure, as there are no industry- standard benchmarks. Rebellion Software has claimed that the Jaguar can render "10,000 Gourard shaded, large, 65536 color, any shape polygons per second," while still performing other tasks. Presumably this level can be increased further with optimized programming; indeed, some unofficial calculations speculate that FIGHT FOR LIFE may generate between 20,000 to 40,000 texture-mapped polygons per second.

A key to understanding the Jaguar's performance is to realize that most effects are accomplished by programming one of the processors to do the job. To perform texture-mapping, for instance, required a developer to write a texture-mapping routine for the GPU and/or blitter, then call it as needed. The general-purpose nature of the Jaguar architecture gave developers a lot of flexibility; unfortunately, the drawback was that software routines for such effects are invariably slower and less efficient than dedicated hardware chips and components.

*  Jeux disponibles :

Scans des boîtes des 19 jeux Jaguar en ma possession.
Liste des jeux sortis et des jeux qui ont été annoncés.

*  Kit de développement en préparation :

Je n'en connais qu'un, le kit de développement "Puma" des frères Favard. Voici sa page d'accueil : http://perso.wanadoo.fr/laurent.favard/jaguar.html

*  Aidez-moi !!!

Je recherche les jeux (par ordre de préférence) :
  1. Attack of the Mutant Pinguins.
  2. Worms.
  3. Brutal Sports FootBall.
  4. Towers II.
  5. Theme Park.
  6. Power Drive Rally.
  7. Val d'Isère.
  8. White Men Can't jump.
  9. NBA Jam TE.
  10. Ainsi qu'un lecteur CD avec Highlander, Myst, Primal Rage, Baldies et surtout Iron Soldier 2.
Fichiers textes ci-dessus et comparaison avec autres consoles.  (ZIP de 10 Ko)
Par GaëlGods Rastan sur Atari TT030.   Dernière mise à jour : le 15/09/2002.
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