IBM PC Network

I don't believe that any of the early LAN products emulated what IBMers would call an FEP. Generally, an FEP is a 37XX computer running NCP, EP or PEP. https://en.wikipedia.org/wiki/IBM_37xx Originally these had an interface to the channel and serial interfaces to which a variety of devices could be connected, so simple async terminals, terminal cluster controllers and RJE workstations. There were also "remote" FEPs that connected to a local FEP via a comms line. Later Token Ring and Ethernet interfaces were added. IBM did produce an emulation of the 37xx boxes as https://en.wikipedia.org/wiki/Communications_Controller_for_Linux but this runs on the mainframe. The early tools generally appeared to the Mainframe as a 3174 Terminal Cluster Controller and attached screen. They did not emulate any of the 37xx or 3174 CPUs, they "just" re-implemented the IBM protocols. So you still (usually) needed an FEP on the mainframe although it was also possible to use a Token Ring interface on a channel attached 3174 (3174s could be directly attached to the mainframe) or even attach to the channel using PC channel cards. The tools were not limited to terminal emulation, they would also allow PC applications to connect to the Mainframe using a range of SNA protocols. I would say they are all old enough and obsolete enough to be considered "in scope" on here. Dave