Tightly-coupled
From Computer History Wiki
Tightly-coupled is the term used to describe a multi-processor system where the individual processors have significant access to each other (e.g. by the ability to have direct access to the main memory used by other processors), unlike the limited connectivity (e.g. through a communication network) seen in loosely-coupled multi-processors.
Examples
Some tightly-coupled multi-processor systems are:
The ILLIAC IV was intermediate between a tightly-coupled and a loosely-coupled system; the Control Processor could see all of main memory, but individual Processing Elements could only see into their own Processing Element Memory, not those of other PEs.
