Problem
1. Declare a string using DCB directive. Write a subroutine that reads every symbol of the string and compares if it is a letter (A-Z, a-z).
2. Declare in the memory four ASCI symbols using DCD macro-directive. Write two subroutines. The first one pack reads these four symbols and packs them in a word packedAscii. The second oneunpackAsciireads the wordpackedAsciiand unpacks itto registersr5 to r8.
3. Write a subroutine that loads a word from the memory and makes permutations: first and third byte; second and forth byte. After that it stores the result in another word in the memory.