In release 0.67, the HP-41CX is now mostly working. I implemented the basic Phineas chip (Time Module) functionality, though apparently the stopwatch uses the TESTB mode which I haven't put in yet. The clock runs at real time, though it is not initialized from nor does it track the system time. Clock mode and alarms work, though there isn't yet sound support. There are various bug fixes and improvements under the hood.
Much thanks to Chris Roccati and Christophe Gottheimer for their work on making the Phineas chip and bank switching work in NSIM, and Thomas Olesen for doing the same for Nonpareil. I didn't incorporate much of their code due to planned infrastructure changes, but used it quite a bit for reference.
Thomas Olesen has been working on Nonpareil sound support using the SDL library, and Christophe Gottheimer has got the HEPAX module working in NSIM. I'll probably merge those changes in the near future.