The Tektronix 067-0911-00 is a diagnostic tool for the 7854.
The 067-0961-00 diagnostic memory board and the MicroLab I are part of this interface
Front view of A3 interface board
Rear view of A3 interface board
Front view of A1 cable termination board
Rear view of A1 cable termination board
Overview of the 7854 diagnostics system