I’ve revisited my TI emulator for the DS. This port is based on new sources, and ONLY supports the TI-85 (which is what I own anyway, so fine with me).
Currently, it seems to function well. Speed is very close to 100%.
There are still a few things to clean up and add (currently no save-states, or any way to transfer files to it), but it is now usuable for most calculations & graphing. The keypad is also nice and responsive (unlike the buggy previous version).
It supports all libfat-compatible devices, which means pretty much anything that takes a CF or some type of SD card. Let me know if it works for you. Be sure to read the included README.txt file!