A General History on The 3DO Hardware



Where it began, and inspiration lay

Trip Hawkins, the founder of EA, started 3DO in 1989 under a secret name. This name, S.M.S.G., was in reference to Trip’s 8th grade class from an acronym in a math textbook. The two People hired for development positions were software and hardware vets, David Needle and R.J. Michal. Supposedly hardware design was initially drawn on a napkin and discussed over a meal. The two had just finished work on the Atari Lynx, two years before, and both worked at Amiga. With both previous projects on their mind, they began designing a system that would use elements of both.


Cel Engine

The Cel engine was 32-bit spiritual successor to the sprite engine of the Atari Lynx, however a Cel is not a sprite nor triangle/polygon. The engine name came from the name given to animation cels in the hand painted production of animated motion pictures.

A Cel is similar to that of a transparent quad, where pixels can be drawn. This allows the engine to produce transparency with ease. A Cel can act as a “sprite” or as a “texture”, with the hardwares ability to place and distort each Cel.



Operating System

The 3DO system was built from the ground up with the intention of a standard format. To keep from relying on hardware compatibility in the future, they took an operating system route, locking out almost all access to the hardware. There was of course an exception for a few small parts, such as custom instruments for the DSP, allowing it to do math operations and other things. With warning to software developers, that not following the OS may lead to compatibility issues with future 3DO systems. The OS had certain operations in use that were the same as Amiga OS. These operations are the use of ‘tags’ in passing a long list of parameters to functions, the concept of item, and similarities in directory structure (the fact that /C is in path by default).

Hardware

3DO hardware was tediously and meticulously pieced together with balance in mind. With the lack of off-shelf components, the system had very little performance loss between each chip. While the native clock of the ARM60 is 25MHZ, in the 3DO it runs at 12.5MHZ. The reason this is, is because the 3DO chips were already in production by the time VLSI got the chip to 25MHZ, not to mention, if sped up, the CPU will have an extra tick for each word access. This sadly kills the performance, and you would only experience a 33% gain from a double overclock. The overclocking task is not easy, however if you manage to, the results are not positive. The system will begin glitching and on button presses and skipping them in most cases, including instruction issues. If you are interested in making a hardware mod for the system’s chipset, please refer the these Service Manuals. If you are interested in software development, please refer to 3DODev.

Quick and dirty run down

CPU:

  • – RISC 32-bit ARM60
  • – 12.5MHZ

Memory:

  • – 3 MB total RAM
  • – 2 MB DRAM
  • – 1 MB VRAM
  • – 1 MB ROM for OS
  • – 32 KB SRAM for Storage

MADAM:

  • – 32-bit
  • – Address Engine
  • – 24.54MHZ

CLIO:

  • – 32-bit
  • – Data Engine
  • – DSP
  • – 24.54MHZ

ANVIL

Revision of the MADAM and CLIO
  • – 32-bit
  • – Includes both previous IC’s and Decoder
  • – 50MHZ

Audio DAC

  • – 16-bit
  • – 16.9MHZ

Bus

  • – 200mbyte/s (50 million words per second)
  • – 50mhz