*.9xk files are Flash-Apps. It's a feature of the AMS (the official official OS of the Ti68k calculators) that is not supported by Pedrom. Flash-Apps are signed applications that run from flash memory while usual applications are copied in RAM before running.

It seam to me that Pedrom support some kind of execution in flash but not the same way as AMS. If i recall correctly there used to be an unofficial version of GTC that runs on Pedrom, but it was never made publicly available.