Why not just write a Unix-native one? They aren't that much work - I created a
uassembler overnight (literally!) for the QSIC project Dave Bridgham and I
have been working on.
Agreed Terry Hayes, tjt and I hacked an assembler and loader for Masscomp together years ago pretty fast. We actually, made all those tools look a lot like the DEC ones because a lot of same HW people were writing the uCode for the Masscomp FP/APs as had written the much of the 11 and Vax code.
[Fun story, that a few other tools that had been written for UNIX that patriots older RSX/VMS support tools were quietly traded to DEC WRL for some HW libraries. We both were using the same brand CAD system and our HW guys wanted some design rule stuff WRL had done for Jupiter, and they wanted UNIX based tools to run on Ultrix].
As for Tektronix earlier, we did not know much about the WSC unit and basically the CSAV/CRET stuff was supposed to be a one shot thing. We just wanted to use the tool that came with it; cause we did not think we were going to do much with it. In hind sight and knowing what I would learn 3-5 years later, writing our own would have made more sense; but I'm not sure it was very well documented.