Yes, on ti83plus (SE) or ti84plus (SE) or ti84plus C SE you have flash memory which is not erased after a ram clear.
So to protect a program, press "2nd" then "Mem", select "Archive" then go to program menu and select the program.
Finally press "enter".
The program will have a star (*) before his name. An archived program can't usually be executed (this is not a flash app) but it will not be erased after a ram clear !