Motorola won‘t provide any microcode updates for PPC, that‘s for sure
I’ve never seen „MC“ used with that meaning. Is this an actual abbreviation of something in this context, or just some random letters?
As far as I know it comes from the MC prefix of some of their earliest consumer chips, i.e. the MC6800 and MC68000. My use of it was by no means an industry standard, just something informal I thought was common in Amiga circles in decades past. I'm sorry to disappoint with a mundane explanation but it probably just stood for 'Motorola Chip'. I can't be bothered following the progress of any relationship between old Motorola and new, and their collaboration with IBM and so on or who would be responsible for what. Nobody's going to update the chips in any case.
...and so the wordage was not avoided
Edit: the term in use http://tinyurl.com/y79eh3jz[ Edited by KennyR 05.02.2018 - 23:41 ]