TRY AGAIN AFTER REDUCING SIZE OF ATTACHMENTS . . . sorry if some of you get it twice . . .
Thank you, Tony! I guess RS-422 could do a link because it is capable of 10 Mbits/second according to Wikipedia. But that still leaves the bed of nails a mystery (what did it replace)? Peering under the TRAM-like thing (which I am afraid to pull because it may have some essential connection with the wire wrap on the bed of nails) I see IMS B008 221-CRBD-302-05 dated 1990, which seems to fit page 3 of my User Guide (also dated 1990), except for CRBD instead of CBRD. But surely the bed of nails is not standard.