reverse the digits

Take 9317 and print 7139: the same digits, reversed, as a number.

Each trip around the loop, peel off the last digit (the remainder mod 10), append it to the running result with result = result * 10 + digit, and cut the source number down by a factor of ten. msubRd = Ra - Rn * Rm. gives you the remainder; maddRd = Ra + Rn * Rm. does the multiply-and-add in one instruction.

what is checked

• the reversed number is printed on its own line
• the program exits cleanly
• the digits are peeled in a loop (msubRd = Ra - Rn * Rm. present, answer not written in)