HP 16550A User Reference page 23

I
Probing
General purpose probing comes as the standard probing option
provided with the logic analyzer. There is a full description of its
components and use later in this chapter.
The Termination Adapter
The optional termination adapter allows you to connect the logic
analyzer probe cables directly to test ports on your target system
without the probes.
The termination adapter is designed to connect to a 20 (2x10) pin,
4-wall, low-profile header connector, 3M-Series 3592 or equivalent.
Termination Adapter
2-4