Use direct addressing in all these programs:

4. Write a machine-language program to input 4 upper case characters, convert them to lower case, and output the result on the output device. Write it in a format suitable for the loader and execute it on the Pep/8 simulator.

Note: you do not need to check that they are alphabetic characters, just assume they are. ALSO, these are characters, meaning they take one byte of memory and when you load them into the accumulator you need to Load Byte, and when you store to memory you need to Store Byte.