Though not since 2011, Air traffic Control Input/Output Processor IOPs ran 40 years from 1971 to 2011 and had a wide USA distribution - so decommissioned not that long ago but did start in a relatively primitive digital time and had a long run.
The Input/Output Processor was an array of maybe 200 cards. Each consisting of what counts today as a few gates to a few hundreds. Its computational strength was in its parallel I/O processing.