Simulation Gallery

Our example is from the Cray 1S range, announced in 1979 and was an enhanced version of the Cray-1A. Unlike the Cray-1A, which used external minicomputers for its I/O to the outside world, the 1S incorporated from 0 to 4 high speed I/O channel processors.

The models ranged from the S/500, with 0.5 Million words of 64bit memory and 0 I/O channels, up to the S/4400 with 4.4 Million words of 64bit memory and 4 I/O channel processors. Ours is a S/2000 which originally had 2 Million words of memory. Even though it is not complete, missing many of the CPU, Memory and Power supplies (under the seats), it still shows the iconic circular shape well known to this range. It was also cooled using a complicated Freon refrigeration system, like the Cray-1A.

If you look at the rear, some of the panels have been removed, revealing several miles of very tightly packed blue/white twisted pair wiring. It is so tightly packed that your hand will hardly move when pressed up against it. It is believed to have taken several people over a year to build, wire and commission some of the larger models.

The reason why the Cray-1 range of machines looked so different to any others at the time was quite simple. It was clear in the initial design phase that in order to get the best possible speed out of the technology of the time, the boards, and thus the interconnections between each one needed to be kept as short as possible, but also the cable lengths needed to be the same length to ensure the timing of signals remained consistent throughout the machine. So the horseshoe design enabled that to be possible.

The Cray-1 we have on display arrived on 26/2/2014 and is on permanent loan from FAST (Farnborough Air Sciences Trust) https://www.airsciences.org.uk/. The machine was installed at RAE Farnborough when operational and afterwards was on display in the lobby of a building there. It was rescued when the building was pulled down and ended up in a container. Some years later it was offered to us for display.

Sadly, this machine will never be operational again due to having so many missing parts, not withstanding the fact that we would need our own power station and refrigeration unit which could easily take up the same space as the museum itself…. at least we would not be cold in the winter, as would anyone else within a mile of us!

The Cray Y-MP range of supercomputers was released in 1988 and was a replacement for the Cray X-MP supercomputer. The X-MP was itself the replacement for the Cray 1.

The Y in the name came from the original footprint. This was based on the horseshoe style of the Cray-1 and Cray X-MP with an additional cabinet holding the processor cards added at the gap, making the overall layout look like a Y.

The Cray Y-MP could be fitted with 2, 4 or 8 Vector processors and have a memory capacity of 128, 256 or 512 Megabytes of SRAM (Static Ram). The initial Model D was Freon cooled like the X-MP and Cray-1. A later Model E left the horseshoe shape behind and was housed in 1 or 2 tall, almost square cabinets, and was water cooled.

The Cray Y-MP EL was released in 1992, with the EL standing for Entry Level. It was a re-design of the earlier Y-MP models utilising CMOS instead of VLSI ECL and could be fitted with up to 4 vector processors and have between 32MB and 1GB of DRAM (Dynamic Ram). This model came in a much smaller cabinet to the Y-MP Model E, and is unusual in it being air-cooled rather than water, and could be powered from a normal 13A mains socket.

Our Cray Y-MP EL was actually upgraded to an EL98 spec - this allowed up to 8 vector processors and 256 megawords (2 GB) of DRAM in a Y-MP EL-style cabinet. It was originally used at Swansea University but eventually donated to the museum from a private collector. The system is operational and runs UNICOS, a Cray variant of UNIX.

INMOS were a British computer company, formed in 1978 and had its base in Bristol. They designed their own range of microprocessors. These were the T400 and T800 range and were designed to be used together in a multi-processor architecture, using purpose built interconnect chips.

The company went on to develop a much faster version of the transputer called the T9000, with a design speed increase of 10x over the fastest T800 currently available. This was initially taken up by CERN, who evaluated an early version with the intent of using it to process the large amounts of data collected in collision experiments. Sadly, the design only achieved a x2 or x3 improvement and was eventually used as a fast gateway dataswitch by CERN. We actually have the system that was used at CERN although it is not on display. As a result of the T9000 being a commercial flop, and the costs involved in a redesign, the company later folding due to financial problems.

Our example consists of a PC (under the table) running applications which then used the Transputer Development System (the grey box on the table) to do the graphical processing to render images using an array of up to 64, T800 transputers. With this we can demonstrate the speed increase that can be obtained by using more and more processors to render various graphical examples like Mandelbrot, Ray Tracing.

EAI PACE TR-48 analogue computer

This model was released in 1961 and was described as a solid-state transistorised computer. It was thought large enough to solve most engineering problems but be small enough to fit into a laboratory. It was considered at the time to be a desktop computer.

It has been set-up to simulate a car suspension system going over a bump, and the resulting oscillation of the spring dampening system employed. The resultant effects calculation is shown on the oscilloscope.

EAI-180 analogue computer

This is a much smaller computer released in around 1972. It has a more limited capability than the much larger TR-48 but can still simulate quite complex problems.

It also uses removable modules so it can be configured in different ways, just like the TR-48.

EAI PACE 231R amplifier module

This is an example of a very early plug-in module for an Analogue Computer and is believed to date around 1958. It is an amplifier module and contains 4 independent operational amplifiers using valves. Later models, as used in the 2 models about utilised transistors to perform the same role.

Analogue computing demonstrations

To give the visitor an idea of how analogue computers work, one of our volunteers has built 3 demonstration units.

The larger unit demonstrates how addition and subtraction can be done using analogue circuits.

The 2 smaller units shows how analogue to digital and digital to analogue conversion can be done using analogue circuits.

Nintendo 64 - Released in Europe in 1997 - 64 bit NEC VR4300 processor with 4MBytes of RDRAM.

5th generation Nintendo Entertainment System. It was the successor to the Super Nintendo.games console.

Sega MegaDrive 2 - Released in Europe in 1990 - 16 bit Motorola 68000 processor with 64KBytes of memory.

4th generation games console. Was a replacement for the Sega Master and was replaced by the Sega Saturn.

Super Nintendo - Released in Europe in 1992 - 16 bit Ricoh 5A22 processor with 128K Bytes of ram

4th generation games console. Replaced the very successful NES and remained in production until 2003.

Atari 2600 (later called Video Computer System) - Released in 1977 - 8 bit 6507 processor with 128 Bytes of memory.

2nd generation games console. Was replaces by the Atari 5200 which did not sell well.

Crazy Taxi - Sega

Sega released Crazy Taxi in 1999. It originally came in 2 versions; This “standard Version” had a cockpit seat, steering wheel, gear shift and peddles for brake and accelerator. The “Compact” or Naomi Cabinet Version” used a newly released Sega Naomi processor (as used in the Sega Dreamcast), did not include the cockpit seat but instead required the player to stand and had all the normal controls.

Our Compact version has proved very popular with out visitors and somewhat addictive to a few! It is certainly the noisiest game in the gallery.

Space Invaders - Taito

Space Invaders was produced by Japanese company Taito and released in Japan in 1978. It proved so popular that in 1980 it was licensed to be used in the USA as both a coin-operated arcade game and for some of the early games consoles like the Atari 2600.

The processor boards used in the cabinet were also used for several other games produced by Taito, so a popular (although not quite legit) ‘upgrade’ was to replace the space invaders game ROM with one that supported many of the games released by Taito, allowing the player to select what game to play. We have upgraded ours in the same way.

Both of our arcade games have needed quite a bit or repair over the years that we have had them, but our every resourceful volunteers have managed to keep them going.