I just bumped this indeed. I have made little progress over the past couple of weeks and find that I want to continue to work on this.
I had a recent idea where one could specify the clock speed of their processor (you aren't going to build things like an ICU or deal with E-Time etc; I won't make it that low level), to pinpoint how fast they want each CPU machine cycle to run. It would be specified through an RTB pref.
I am still sticking to the 16 bit addressing scheme as well. 32 bit memory addresses seem too complex for a simple building game, don't you think?