KEF11-A floating point chip
From Computer History Wiki
The KEF11-A floating point chip is an optional chip for PDP-11 CPUs which use the F-11 chip set. It implemented the FP11-compatible floating point.
The KEF11-A requires the KTF11-A memory management chip, since the floating point registers are actually in the KTF11-A (probably because the KEF11-A is microcode, and there aren't enough pins for both the data bus, and the microcode bus).
The KEF11-A is another dual carrier (with the chips being DEC part # 23-002C7-Ax and DEC part # 23-003C7-Ax; only the A revision of both has been seen).
