Sharp EL-9300C any undocumented features?

[Sal]

I just fixed up a Sharp EL-9300C. It looks like it can use the CE-50P printer and cassette interface that I have.

** Does anyone know of any undocumented features? **

I will explore saving programs to the cassette port and reading the audio to try to figure out the interpreter tokens. Then, create and upload unknown ones and see what shows up on the LCD program listing. (?)

Unless there is something like PEEK, a physical dump of the ROM is all I can think of. If there is also ROM on the CPU chip die I don't know how to do a dump.