The T400 µController is an implementation of National's 4-bit COP400 microcontroller family architecture. It is intended to be used as a replacement for the original chip in SOCs recreating legacy systems.
Its final target is to provide design variants that are compatible with the COP420/421 and COP410L/411L family members. All of them derived from the common t400_core design.
At one point, Open Hub analyzed source code for this project based on code location(s) available at that time. Since then, the code locations have been removed.