Hi I was reading the 3DO FAQ and it refers to the 3DO having "two accelerated video co-processors". Can anyone help shed light on what is being described: Are they identical, or do they perform different functions? If they are different, what does each respective co-processor do? Also, the FAQ describes the 3DO having a custom, fixed point matrix maths co-processor. Does anyone have more detail on the capabilities of this processor? Specifically: What speed it was clocked at? What's the design architecture of the maths co-processor (RISC/CISC/DSP)? Was it independently programmable or just used by other chips (e.g., to do rotation/scaling calculations by the graphics co-processors)? Is the maths co-processor part of MADAM, CLIO or external to both? The 3DO is a fascinating design, but there is little documentation online. Does anyone have any details on the internal workings of the 3DO? Thanks for any details. JR
I asked the same question to the author of Freedo (felixl) some years back. I'll just copy and paste the relevant parts of his response: 50+50+25+25+12.5=162.5 MHz bandwith, (CEL+CornerEngine+VDLP+DSP+ARM) or roughly 1950MHz of host machine for LLE emulation it has 5 risc processors CEL engine, where cel stands for textured quadrilateral, i really don't know why they have called it CEL CornerEngine - RISC processor, capable of vertex calculation and transformation, and 4*4 matrix math : multiplication by another 4*4 matrix, multiplication by vector, dot product, rotation VDLP - Video Display Line Processor. RISC processor, capable of executing up to 35 commands per scan line of TV, providing fast, per pixel CLUT changing, extrapolation, interpolation, custom filtering of the TV scan lines Dsp is Big endian 3do was more powerfull than mac computers of that time, latest dev kit using 3do dev station as compilation farm as well dsp was used for preprocessing (compiling programs)
The main processor uses ARM instructions, although it's not a real ARM chip as far as I've been told. NEC invented a device that clones chips (possibly using logic analysis) and used that on the ARM, then manufactured their own, but I think it doesn't achieve quite the same thermal efficency as the original did. When ARM found out the chip was cloned and because ARM were to small at the time to sue anyone let alone a massive corp. like NEC, they asked NEC to at least mark it with the ARM logo. ARM later bought the chip cloning tech. from NEC, probably just to prevent future stuff like that happening again.
Thanks for the reply! From the specifications in the 3DO FAQ, there is the ARM cpu, the custom NTG designed maths co-processor (presumably the Corner Engine in your description?), the sound DSP, two Graphics Animation Processors and the Video Processor (which I'm assuming is the VDLP). The implication here is that there are therefore two CEL engines.
