Australian Personal Computer

RISCy Business

from the December 1985 issue of Australian Personal Computer

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The Reduced Instruction Set Processor (RISC) era has begun, albeit quietly, and working examples are now appearing on the market. Dick Pountain examines three such processors.

What exactly is a RISC, and why is it a good thing? A reduced instruction set processor, as the name suggests, is one which can execute only a small number of different instructions, compared to the prevailing standards of the day. In computing (as indeed in most walks of life) everything is a trade-off. A RISC processor trades off the number of instructions available to the programmer for speed; RISC processors can execute many times faster than their more complex brethren. When implemented as microprocessors in silicon, RISC designs also save precious space on the chip; smaller chips can be designed and debugged more quickly and cost less to fabricate.