1. A computing system for performing externally-specified mathematical operations on externally-specified subarrays of an array of data words stored in a system memory (SMEM) having a memory I/O port, the system comprising: (a) a system bus, said system bus being coupled to the memory I/O port for transmitting data words to and from the SMEM; (b) alignment means, said alignment means being coupled to said system bus for controllably selecting data words from said system bus; (c) block processing means for performing a block operation on at least one computational block of data words, said block processor means comprising a set of processors and block storage means for storing said at least one computational block of data words, said block processing means being coupled to said alignment means. (d) decomposition and control means for receiving an externally-supplied command packet specifying the location of at least one subarray in said SMEM and specifying an operation to be performed on said at least one specified subarray, for defining computational blocks of data words from said at least one specififed subarray, for decomposing said operation into a series of block operations on said defined computational blocks, and for generating control and address signals to control and configure said SMEM to perform, at a burst transfer rate, at least one burst transfer of a plurality of data words onto said system bus, including the words contained in a first one of said defined computational blocks, and to control and configure said alignment means to select the words contained in said first defined computational block from said burst transferred plurality of data words on said system bus, and to control and configure said block processing means to transfer said selected words of said first defined computational block to selected storage locations of said block processing means, and to perform a first one of said series of block operations on said first defined computational block, said decomposition and control means being operatively coupled to said SMEM, said alignment means, and said block processing means.