There are reasons for machine designers to want allinstructions to be the same length. Why is this not a good idea ina STACK machine?

Answer and Explanation:

It is generally seen that instruction are of same length in a machine design. But this is not a good factor for the stack machine as there is the function of push and pop which requires addresses and opcodes for the execution of the arithmetic operation. So, there will be lot of waste of memory space if the length of the instruction are of same. That is why stack machines should not have same length instruction.