Research Project Re: Graphics Processor

The last time I did something like this, I used normalised homogenous coordinates to represent the points. That way, all the affine transformation matrices can be multiplied together into a (3x3 or 4x4) matrix, and a single matrix multiplication is used to apply the aggregate transformation to a point in 2D or 3D space.

I do not know if this is commonly used, however.

Regards, Allan

Hi,

Try reading up on the TMC2301 / LF2301. This is an image processor that's been around for a while.

Eric

INMOS made a 2-D image processing chip. I still have the databook (1989!).

Essentially it was a digital signal processor fully implemented in hardware, as opposed to DSP chips that are just microprocessor architectures optimised for DSP in software.

It looks like it could be implemented in today's FPGA chips relatively easily.

What's the part number? I know about the G300 and its predecessors but they were just a display controller (you could setup various resolutions and color depths). If you are referring to the T4xx/T8xx transputers they could be used as a display controller but it didn't really contain any specialized instructions for displays or graphics. The Intel i860 had instructions designed for computer graphics and displays. SGI even used it in their Reality Engine and Reality Engine

1. It was later replaced in the Infinite Reality Engine with ASICs.

In the early 1980's NEC made the 7220 a graphic display processor (GDP) capable of display 4096 x 4096 with as many colors as your video DAC supported. It had functions for text, cursors and 2D operations.

In the late 1980's Intel came out with the 82786 Graphics Coprocessor. I never worked with it so I can't comment on it.

I'm also working on a similar project for my personal interest. I found these website that might be of interest to you:

No source but very informative:

Not much going on with it at the moment. If I remember right they have taken the project in a new direction.

This one is currently broken but it was an example of a graphics pipeline and they included the source files. Hopefully it will be fixed soon.

It's in German but looks very impressive:

If you find any interesting links I'd be interested hearing about them.

Derek

I think it was A100 and/or A110.

Jan

The only time I saw those used for graphics was an early B429 TRAM. It captured video in real time and munged it. According to the 1991 "iq systems" databook it carried two A110's and a T800. IIRC it ran convolution filters in real-time, fun demos.

Cheers, Rupert

--
Threading sequential code through the eye of a parallel needle
makes little sense. ;)

A100 and A110

Indeed, based on the 6845.

I've coded for both and I really can't ever recall thinking that a G3xx was anything like a 6845, so I am a bit surprised to see a claim that they were "based" on them !

IIRC G3xx parts had VTGs, memory interfaces and CLUTs (also used for gamma correction). I think that G332/G364 had hardware cursor support.

They were pretty easy to code for, I liked them a lot.

Cheers, Rupert

--
Threading sequential code through the eye of a parallel needle
makes little sense. ;)

A121 rings a bell, vaguely. It was a fast 2D DCT processor rather than general purpose image processing, probably aimed at the MPEG market.

Come to think of it, the core may live on in SGS digital TV chips.

On the original topic, there are good notes on computer arithmetic and ALU design around. Best online introduction I have found was some course notes from Reto Zimmermann at ETH Zurich, downloadable from this page.

For CORDIC, also see Ray Andraka's page, I think

And for a VHDL starter, google for Peter Ashenden's "VHDL Cookbook" ... his paper book is also recommended.

- Brian

:

Checking the databook:

A100: Cascadable signal processor A110: Image and signal processing sub system A121: 2-D discrete Cosine transform image processor B009: DSP system evaluation board D703: DSP development system

People might want to check out the videocore processor at

8 billion ops at 50 mW. I've seen it do real time video processing that used to need a Quantel multi-transputer system costing tens of thousands. Now it is in mobile phones at a few quid per chip...

I wasn't really trying to compare them in sense that this device could be used in place of that device. I was trying to show a time line of evolution from a pretty simple device to a more complex. I remember coming across the 6845 in devices that didn't require a high-end device like video terminals and arcade games.

Derek