I've not seen/heard of HDLC microcode for the KMC. But I guess it would
be theoretically possible. But I wonder if anyone have the docs and
tools to create new firmware for the KMC today...
VAX P.S.I. in DECnet Phase IV used to support KMC11-based devices. I think the microcode even did LAPB on board, leaving the host to do X.25 L3 only. In practice this was more trouble than it was worth, and these devices were not supported for Phase V.