On and off (mostly off) for over a year now, I've been working on an emulator. I've recently gotten around to working on it, and I've gotten it to a point where it boots the TIOS. Currently, it's only for the TI-84 Plus C SE, because I'm just lazy and don't feel like writing all that wacky bit-manipulation code for the B&W LCD. (Hard? No. But I just said lazy.) Anyway, here's a screen shot of me in the program editor. The source code is on Github.

Current features:

• Boots OS4.0
  
• Has framework to support B&W models
  
• CPU instruction trace for the last for 65536 instructions (eats 2 MB of memory)
  
• I/O port log
  
• LCD log
  
• Breakpoints
  
• Memory hex editor
  
• Can run at full speed on a 4 GHz processor
  

Bugs & issues:

• Currently gets stuck in some code on page 6 (around 4974h) that keeps checking the link-assist status, so it runs really slow
  
• No flash emulation
  
• Can't load or export any apps or programs
  
• LCD reading is probably broken
  
• Lots of small issues due to unimplemented stuff