H  36 position edgecard socket J1 RJ 45  J2  RJ45 T1 PE-64570 T  Terminator?

W Terminator? Y2  16.00000 MHz osc ZM2 M5M5179P-45 ZM4 25F8241 ZM5  74F7673

IBM PC NETWORK-BROADBAND
       IBM's broadband PC Network addresses the specialized requirements of customers who are combining their LAN with other services, such as video, voice, security and/or additional data
channels on a common broadband medium.  It may also be used to meet the requirements of small businesses and individual work groups.
IBM PC NETWORK ADAPTER II: The IBM PC Network Adapter II is a feature card for connecting the new IBM Personal System/2 Model 30 and IBM Personal Computers to the broadband IBM PC Network.  It is compatible with the form factor and bus design of the original Personal Computer, yet it is designed to take advantage of greater Intel 80286 and 8086 processing speeds.
       The IBM PC Network Adapter II supports the NETBIOS interface and the 802.2/Logical Link Control (LLC) protocols via the IBM LAN Support Program which was also announced today.  This allows the adapter to provide access to IBM PC Network and IBM Token-Ring
Network applications written to the NETBIOS or APPC/PC interfaces.
       The IBM PC Network Adapter II is also compatible with the protocols of the original PC Network Adapter via the IBM PC Network Protocol Driver program  which was also announced today. This allows the adapter to take advantage of the same protocol and interface as
the original IBM PC Network. See IBM Product Announcement 187-079, dated April 2, 1987, for details.

IBM PC NETWORK ADAPTER II/A: The IBM PC Network Adapter II /A is a feature card specifically designed for connecting the new IBM Personal System/2 Model 50, Model 60, Model 80-041, and Model 80-071 computers to the broadband IBM PC Network. It is compatible with the form factor and bus design of these new Personal System/2s to take
advantage of greater Intel 80286 and 80386 processing speeds.
       The IBM PC Network Adapter II/A supports the NETBIOS interface and the 802.2/LLC protocols via the IBM LAN Support Program which was also announced today.  This allows the adapter to provide access to IBM PC Network and IBM Token-Ring Network applications written to the NETBIOS or APPC/PC interfaces.
       The IBM PC Network Adapter II/A is also compatible with the protocols of the original IBM PC Network Adapter via the IBM PC Network Protocol Driver program which was also announced today. This allows the adapter to take advantage of the same protocol and interface as the original IBM PC Network. 
      The IBM PC Network Adapter II/A is not designed for use in the IBM Personal System/2 Model 30. See IBM Product Announcement 187-080, dated April 2, 1987, for details.

I think this is the original 2Mbit/Sec PC Network. The port is a BNC. The module is shown without the EMC cover.

   I have a similar card that has the module used in the broadband adapter above. Possibly this card/module combination could be used as a baseband or broadband with the swapping of the module. The slot cover and module are attatched to the base card with two screws. To swap the module, you unscrew both screws on the back of the base card and then screw on the new module after plugging it in the socket.