Hello , i'm currently implementing a calculator in MIPS which uses the polled I/O method for fetching information. I put a

beq $v0, 120, exit # exit if input = ('x')

on the main part of the code to tell that whenever something is fetched is equal to x, it should branch the exit function. The only problem is that my code works fine with the keyboard/display simulator on MARS but i get the interrupt exception 6 on SPIM. Why is this happening and how can i help it ?

//Thx in advance