There are several important issues that must be considered in the design of highly parallel SIMD machines. Factors such as machine programmability, support for flexible interprocessor communications and a suitable I/O system all contribute to the design of a successful SIMD computer system. The microprocessor array (μPA) is an SIMD design study performed in conclusion to an Alvey funded project to design and implement a reconfigurable processor array (RPA), a single-bit processor array design. The design study differs significantly from its predecessor and rectifies its deficiencies, in both technological and programmability areas. The proposal is for an array of 1024, 8-bit wide processing elements, each one of which has its own communications coprocessor. It supports a versatile packet switching network which operates concurrently with processing. Other features include support for high speed floating point operations, fast I/O and novel mechanism to support local conditional statements within the array, which greatly aids programmability.