> From reading the book, I learned that Cutler had the same mentality for his OS and, in fact, the system wasn’t ported to x86 until late in its development.<p>The reason for this is that the RISC architectures at the time (MIPS, Alpha AXP, PPC) had weird ISAs. There are things like branch delay slots and MIPS in particular required aligning to a 32-bit boundary (x86 does not). Dave Plummer has a YT channel and I highly recommend his interview with both Dave Cutler and Raymond Chen. It was a lot of work to port to these other architectures, and they didn't have source control at the time, so they were hand merging these changes.