The AN/UYK-44 computer is the standard 16-bit computer installed in U.S. Navy surface, submarine, and ground C4I platforms. The UYK-44 provides computing power for more than 40 different command, control, communications, and weapon systems. One of the most interesting applications of the UYK-44 is as the control computer of the Navy's AEGIS weapon system, which tracks and identifies targets, and controls the ship's defensive equipment.
The UYK-44 was first developed in the 1980's and continued in use through the early 2000's. It is being phased out in favor of commercially available systems. Here is a chart from a Navy presentation showing the phasing of central Aegis processors.
While the UYK-44 has feeble computing power by our standards, it has massive I/O capability. Each pair of connectors on the back provides a MIL-STD-1397 point-to-point I/O bus running at 250K words/s. Our version has 16 such buses.
However, our device is actually the commercial version (ES-44) of the military spec UYK-44. The implementation is different, but the ES-44 is functionally compatible (code, I/O bus, and instruction timing) with the military UYK-44 version. As can be seen in the UYK-44 picture on the front of its manual (which we have), the front control panel of the ES-44 is also the same as the UYK-44's.
Our ES-44 works: it turns on and boots. At that point, however, it waits for the missing I/O: radar, missiles, etc.