Housed within inertial shock dampers within each battle unit, the CPU gives Skynet the ability to control it's units directly, or allow them to function by themselves, learning from a pre-programmed knowledge base as they go. This means that each battle unit has the potential to adapt to it's situation, and literally reason through problems and tactical maneuvers. In the case of the various Terminator series, this means that they can learn to behave more like humans in order to be better equipped for infiltration.
Terminator 2: Judgment Day
Working on the top secret project at Cyberdyne Systems, Dyson dedicated his life to the development and production of the Central Processing Unit, sometimes to the detriment of his family life. Surrounded by like minded scientist, and working in Cyberdyne's expansive labs, Dyson had the run of the best design and testing facilities available. Creating a strong "community" bond and relaxed working environment, Dyson was soon able to increase productivity and earn the respect of his fellow researchers.
After many long years of work, Dyson eventually hit upon a prototype model that was not only worked and was bug free, but was superconductive at room temperature, making it extremely powerful. It marked the beginning of the end.
The CPU was modeled and designed primarily on computers in advanced 3-Dimensional programming packages, where simulated testing could be done in real time, or at increased rates.
The lattice of cubes in the construction of the prototype CPU suggests a "hypercube", a cube of more than three dimensions. In computer design, hypercubes are used as a physical connection scheme that minimizes the effective communication distance (and therefore the time delay) between processors, when the logical connection scheme needed by the software that will be run on those processors cannot be known in advance. This then supports the Neural Nets ability to learn, adapt, and built new logical connection schemes.
The Neural Net CPU is ground breaking, using the very latest Quantum Effects chips. Until Dyson designed the CPU, computers were powered by chips composed of millions of transistors. Computing in the old way was done in the binary system - 1's and 0's, on's and off's. With the QE brain in which many more computations can be done each second, quadrillions of switching positions are possible, many of them simultaneous at each quantum level. All this happens down around the Planck length (theoretically the smallest measurement possible) - so infinitesimally small that superstrings are the major league players. Superstrings are strange 10 dimensional building blocks that are more than one thousand billion billion times smaller than a single proton in the nucleus of a hydrogen atom.
Terminator 3: Rise of the Machines
After Miles Dyson's untimely demise and the destruction of the main Cyberdyne Systems complex, Cyberdyne was taken over by the US military and renamed Cyber Research Systems. Under the guidance of program director Lieutenant General Robert Brewster, CRS continued Dyson's groundbreaking work, eventually completing the Neural Net CPU.
The finished CPU is a form of thick, more 3-Dimensional, circuit board which is approximately 35 mm in diameter. It is basically constructed from a number of rows of blocks connected by pipes. The reasoning behind this design was similar to that which evolution has independently discovered in "designing" the human brain: the system has to be massively parallel, and requires excellent communication channels between processors. Therefore there are many blocks, each with many processors, and while local communication within a block is readily supported, there is also some large "data pipes" between blocks to allow more limited long-range communication.