Illinois Automatic Computer | 1951 ~1974

 

ILLIAC (Illinois Automatic Computer) was a series of supercomputers built at various locations, including the University of Illinois at Urbana-Champaign. A total of five computers were built in this series between 1951 and 1974, and some modern projects also use the name.

Architectural Blueprint

The architecture for the first two UIUC computers was based on a technical report created by the Institute for Advanced Study (IAS) at Princeton University. This report was edited by John von Neumann and included ideas from Eckert, Mauchley, and many others. The designs in this report greatly influenced computing in the 1950s and were used as a blueprint for many other computers, including the two at the University of Illinois, which were completed before Princeton finished the JOHNNIAC. The University of Illinois was the only institution to build two instances of the IAS machine.

ORDVAC

ORDVAC was the first of two computers built under contract at the University of Illinois. It was completed in the spring of 1951 and passed its tests in the summer. In the fall, it was delivered to the US Army's Aberdeen Proving Grounds, where it was checked out in about a week. As part of the contract, funding was provided to the University of Illinois to build a second identical computer, known as ILLIAC I.

ILLIAC I

ILLIAC I was built at the University of Illinois based on the same design as ORDVAC. It was the first von Neumann architecture computer owned by an American university and was put into service on September 22, 1952. ILLIAC I was constructed with 2,800 vacuum tubes and weighed about 5 tons. By 1956, it had gained more computing power than all computers at Bell Labs combined. Data was represented in 40-bit words, with 1,024 stored in main memory and 12,800 on drum memory.

Immediately after the launch of Sputnik in 1957, ILLIAC I was used to calculate an ephemeris for the satellite's orbit, which was later published in Nature. ILLIAC I was decommissioned in 1963 when ILLIAC II became operational.

ILLIAC II

ILLIAC II was the first transistorized and pipelined supercomputer built by the University of Illinois. ILLIAC II and IBM 7030 Stretch were two competing projects to build first-generation transistorized supercomputers. ILLIAC II featured an asynchronous logic design and, at its inception in 1958, was 100 times faster than competing machines. It became operational in 1962, two years later than expected.

ILLIAC II had 8,192 words of core memory, supported by 65,536 words of storage on magnetic drums. The core memory access time was 1.8 to 2 microseconds, while the magnetic drum access time was 7 microseconds. A "fast buffer" was also provided for storing short loops and intermediate results, similar to what we now call cache.

ILLIAC III

ILLIAC III was a fine-grained SIMD pattern recognition computer built by the University of Illinois in 1966. Its initial task was to process images from bubble chamber experiments used to detect nuclear particles. It was later used for biological images but was destroyed in a fire caused by a Variac shorting on one of the wooden benches in 1968.

ILLIAC IV

ILLIAC IV was one of the first attempts at a massively parallel computer, designed with up to 256 processors to handle large data sets in what is now known as array processing. The machine was to have four quadrants, each containing a Control Unit (CU) and 64 Processing Elements (PEs). Initially, Texas Instruments committed to building the Processing Elements using large-scale integrated (LSI) circuits. However, several years into the project, they backed out, stating they could not produce the LSI chips at the contracted price. This required a complete redesign using medium-scale integrated circuits, which led to significant delays and increased costs. Consequently, the system was scaled back from four quadrants to a single quadrant.

Starting in 1970, the project became the subject of student demonstrations at Illinois. Initially, students claimed the project had been secretly created on campus. When that was proven false, the focus shifted to the role of universities in classified military research. ARPA wanted the machine room encased in copper to prevent off-site snooping, but Slotnick refused. He insisted that all research conducted on ILLIAC IV would be published. As a result, the machine was delivered to NASA Ames Research Center in 1972 instead of Illinois. When the first (and only) quadrant was operational at NASA, it was 13 times faster than any other machine operating at the time. The Control Unit, a few PEs, and its 10-megabyte drives can be seen today at the Computer History Museum in California.

CEDAR

CEDAR was a hierarchical shared-memory supercomputer completed in 1988, led by Professor David Kuck. This symmetric multiprocessing (SMP) system embodied advances in interconnection networks, control unit support for parallelism, optimizing compilers, and parallel algorithms and applications. It is occasionally referred to as ILLIAC V.

ILLIAC 6

The design of ILLIAC 6 began in early 2005 at the University of Illinois Urbana-Champaign, led by Luddy Harrison. It was intended as a 65,536-node communications supercomputer utilizing commodity digital signal processors as computation nodes, designed for over 1.2 quadrillion multiply-accumulate operations per second and a bi-sectional bandwidth of over 4 terabytes per second.

Trusted ILLIAC

The Trusted ILLIAC was completed in 2006 at the University of Illinois Urbana-Champaign's Coordinated Science Laboratory and Information Trust Institute. It was a 256-node Linux cluster, with each node having two processors. Trusted ILLIAC nodes contained onboard FPGAs to enable smart compilers and programming models, system assessment and validation, configurable trust mechanisms, automated fault management, online adaptation, and numerous other configurable trust frameworks. The nodes each had access to 8 GB of memory on a 6.4 GB/s bus and were connected via 8 GB/s PCI-Express to the FPGAs. An 2.5 GB/s InfiniBand network provided internode connectivity.