What the TAAC-1 Is

The TAAC is a large (even by VME bus standards) double-plane board that fills 3 slots in a "deskside" chassis Sun. I realise the photo is a bit blurry, but off to the left is a 1 foot wooden ruler, making the card about a 15 inch square, and it weighs about 12 pounds. There are eight BNC type connectors (visible in the upper right of the photo), 4 for video in and 4 for video out (RGB+Sync). A large amount of RAM chips and some large square chips (I assume they are processors) populate the board. As the board is really two boards stacked one on-top of the other, I wasn't able to get a very clear look at the lower board.

I was naturally curious as to what the board did. Despite it's name, my Sun 3/160 didn't seem to run any faster regardless of whether the board was in it or not, and I couldn't get video out of it simply by connecting a monitor. Thus, I tried to figure out how I could access the card, since it seemed to have it's own ram and processors. It looked like a "computer within a computer", and I started my search for information.

A web-search was mostly fruitless - I have posted that info via this link - so, instead, tried to find those responsible for the creation of the TAAC-1.

Locating the Creators

On January 7th, I located some of the people who first built the TAAC-1. The board was originally built by TRANCEPT SYSTEMS, and later on, the company was sold to Sun Microsystems.

Nick England, former President of Trancept Systems, recounts:

The TAAC could drive a separate monitor but normally it was hooked up to
provide a full color window on the regular monitor. You did this by
running a cable from the standard Sun RGB output into the TAAC, then
hooking the TAAC to your monitor. The TAAC had a "chroma-key" circuit
so that when it saw a window of a particular color coming from the standard
board, it would replace that window with TAAC-generated video.

Why do this ? When we developed the TAAC we were a really small company
and didn't want to port the whole windows system onto the TAAC. Using the
chroma-key, we could automagically become a window. Later, when we were 
bought by Sun, we could have ported the window system I guess but it made
more sense to concentrate the TAAC on other tasks, like graphics, imaging,
volume visualization, etc.

Paul Ramsey, the engineer charged with creating the initial development environment back in 1986, offers further information:

   The TAAC stands for Trancept Application ACcelerator. It was designed for
accelerating scientific visualization tasks which needed high performance
(at the time) graphics integrated with computational tasks. Other than a
few demos which may have come with it it didn't do anything unless you
programmed it. Most programs consisted of two parts. The host portion which
usually contained the bulk of the program, and the TAAC part which contained
accelerated versions of certain key algorithms. Libraries were provided for
doing communication between the Sun and the TAAC. There was a C compiler,
an assembler, and some libraries for doing certain common tasks.

   If the Sun has a color frame buffer, the TAAC-1 shares that monitor. The 
output of the color frame buffer is connected to the input of the TAAC-1 which
then goes to the monitor. The TAAC would insert it's video wherever a particular
color was being displayed.

   Unless you are seriously interested in programming ancient hardware just
for the experience I would recommend that you not bother getting into it. The
cheapest PC's available today are much faster than anything you can do with
the TAAC. It has 200 bit instructions but the clock is only 8Mhz so even
after considering that it can do 2 ALU ops, 2 float ops, a barrel shift,
a table lookup, and a memory I/O operation every cycle it would only be the
equivelent of a 56Mhz machine under the best circumstances and since it
isn't a general purpose machines the "best circumstances" are pretty rare.

So, if you have a TAAC, and don't know what to do with it...

Now - where to find software and documentation? You might try asking on the comp.graphics usenet groups and see if there are any folks still running a TAAC or who might have some software or docs.


While ancient hardware actually is something I'm interested in (why else would I own a Sun 3?), programming the TAAC just didn't seem like something I was going to find the time for. Paul Ramsey expressed interest in obtaining my TAAC for memorabilia reasons, and so, I pulled the card and shipped it off to him. The SUN runs alot cooler with the board out and frankly, I'm trying to find RAM to fill those slots. A "high-end" graphics engine is too much of a luxury on a Sun 3.