Question

Q3. Lets assume that a main program writes three Address pointers saved in what a0 points to, then write a subroutine to branch to those three addresses in sequence (one by one) and when finished return control back to the main. Do not forget to bring back back all the used registers before returning to main?

Q4. When the address of the of the interrupt handler routine of Undefined Instruction is starting in memory at address 0x280, then where and what should be written in that exception vector address designated for this type of interrupt?