The Pixar Image Computer (PIC for short) was an image processing computer originally developed by the Graphics Group, the Lucasfilm computer division which would later become Pixar Animation Studios. It was designed for high-end visualization applications.
History
In 1979, George Lucas recruited people from the New York Institute of Technology (NYIT) to start the Graphics Group, the group was set to develop digital printing, digital audio, digital non-linear editing, and computer graphics. In regards to computer graphics, the quality wasn't good enough, due to technological limitations at the time. For the next few years starting from 1979, the team developed a hardware project to solve this conundrum, building what would be called the Pixar Image Computer, a machine which would have more computational power to produce images at a higher resolution.
In 1984 at the SIGGRAPH computer graphics conference, the Graphics Group showcased the Pixar prototype there. A partially-completed version of The Adventures of André & Wally B. was also showcased at the 1984 SIGGRAPH conference.
On February 3rd, 1986, three months after Steve Jobs acquired the Graphics Group, which is renamed Pixar, the Pixar Image Computer became available commercially for the first time. It was aimed at commercial and scientific high-end visualization markets, such as media production and medicine. It sold for $135,000, and while it generated a lot of single sales, it was not sold in quantity.
In 1986, Pixar developed the second-generation Pixar II (P-II for short) computer, which sold for $30,000 as an entry-level model.
In a bid to gain a foothold in the medical market, Pixar donated ten Image Computers to leading hospitals and sent marketing people to doctors' conventions. This had little effect on sales, despite the machine's ability to visualize CAT scans and show perfect images of the human body. Pixar did get a contract with the manufacturer of CAT Scanners, which sold 30 machines. The terms were: Buy a million-dollar scanner, and get a $30,000 3D visualization system for free. However, doctors were not trained to look at images in 3D, and could be sued unless they looked at the individual slices, per their training. By 1988, Pixar had only sold 120 Pixar Image Computers.
In 1988, Pixar began development on the PII-9, a 9-slot version of the P-II that is intended for use by government agencies in high-end imaging applications done by dedicated systems produced by the aerospace industry, which cost a million dollars per seat. The PII-9 and its associated software became the prototype for the next generation of commercial "low-cost" workstations.
In 1990, despite that Pixar was defining the state-of-the-art in commercial image processing, the government decided that the per-seat cost was still too high for mass deployment, and to wait for the next generation of systems to achieve cost reductions. This decision had lead to Pixar laying off its hardware engineers and selling the image computing business to Vicom Systems (which later went bankrupt) for $2,000,000. Because there were no high volume buyers for the system in any industry, less than 300 Pixar Image Computers were ever sold.
Many of the lessons learned from the Pixar Image Computer were applied to the Low Cost Workstation (LCWS) and Commercial Analyst Workstation (CAWS) program guidelines in the early and mid 1990s. The government mass deployment that drove the PII-9's development had occurred in the late 1990s, in the Integrated Exploitation Capability (IEC) program.
Technical Details
Channel Processor (CHAP)
The Channel Processor (CHAP for short) is a four-way parallel (RGBA) image computer made up of four 16-bit AMD 21116 bit-slice processors (each running at 10 MHz) and four Logic Devices LMU17 16 x 16 hardware multipliers in an SIMD (Single Instruction Multiple Data) architecture, which was ideal for imagery and video applications. It can execute instructions at 40 MIPS, making it 200 times faster than a DEC VAX-11/780, which was a popular system at the time. The CHAP processed four image channels in parallel; One for red, one for blue, one for green, and one for transparency (alpha channel). The CHAPs can communicate with each other and other peripherals over a 80 MB/sec YAPBUS (Yet Another Pixar Bus), and to picture memory (VRAM) across the 240 MB/sec PBUS (Processor Access Bus).
Specs
- No. of parallel processors per CHAP: 4
- No. of CHAPs per system: 1 to 3
- Data word width per processor: 16 bits
- Clock cycle time: <100 ns
- Control store memory: 16K words (96-bit words)
- Scratchpad memory: 16K x 16-bit words x 4 (64K words total)
- Memory bus bandwidth: 240 MB/sec
- YAPBUS bandwidth: 80 MB/sec
Memory
The PIC and variations thereof can accommodate 12 to 192 MB of image memory (VRAM), storing full-color pixels at 48 bits for each pixel. The pixels use 12 bits for red, green, and blue, plus 12 bits for the alpha channel. Memory bandwidth is at 480 MB/sec.
Interfacing to Host Machines
The PIC has no direct user interface, so it cannot be used on its own. For this, it requires a Unix-based workstation acting as a host machine to operate it (at least to provide a keyboard and mouse), from brands such as Sun Microsystems or Silicon Graphics. The system interfaces to the host machine via the SYSBUS. It is used as a special-purpose graphics system for a variety of host machines, from personal computers to supercomputers. The host machine can be positioned up to 30 feet from the PIC.
Video Output
The standard video output board of the PIC has a high standard screen resolution of 1024 x 768 pixels interlaced, and a high broadcast quality standard RGB output of 525 lines (625 lines for PAL regions). It has 3 color lookup tables (10 bits in, 10 bits out), 10 bits per DAC, and a video bandwidth of 480 MB/sec.
Chassis
The original PIC boasts a rack-mounted box chassis measuring 21" x 19" x 30" with 12 slots for expansion boards, and weighs 100 to 150 lbs (45 to 68 kg).
The minimum configuration holds six boards, comprised of one CHAP, one video board, one memory controller, and three 8 MB memory boards. This can be expanded to three CHAPs, two video boards, and six memory boards.
The P-II (Model 820204) uses a chassis that could accommodate four expansion boards, eight less than the original, considering that it is meant to be a low-cost model. A variant of the P-II features five expansion board slots. It is distinguished by a redesigned front faceplate. It is slightly smaller than the original PIC at 21" x 17.5" x 23.5", and weighs 140 lbs (63.5 kg).
The PII-9 uses a similar rack-mounted form factor to the original PIC, with the exception that it could accommodate nine expansion boards, rather than twelve.
Power
The PIC runs on 190 to 250 volts of AC power @ 20 amps, single phase, at 47 to 63Hz
Software
The Pixar Image Computer comes with an extensive software package, which was developed in-house by Pixar under Unix 4.2 in both the C and Assembly languages, for developing applications.
Gallery
