A minicomputer micxoprogrammable, arithmetic processor

Except for a few notable examples, all computers have been designed as "adder-central" architectures. "Adder-central," as used here, refers to an organization which places the Arithmetic Logic Unit (ALU) at that junction of the system through which all data must flow — thus creating a bottleneck. In the early days, when adders were expensive, cost considerations precluded more than one ALU. Nowadays powerful ALU's are available at very low cost and a designer, even of minicomputers, can consider placing more than one ALU in a system.