I decided to forward this one to you all, since it points out a frequent careless error, which I want you to be sure to check before turning in your final exam. The issue of course is hex (x) vs. decimal (#).

A student writes:

     Hello Dr. Patt,

     I think that the solution to problem 6.17
     on page 175 in the book should be x3210 JSR #10 as the PC points
     to x3220 after x3210. The solution currently shows JSR #15,
     which I clearly think is wrong! (Probability: 99.99%)

     << name withheld to protect the industrious student >>

Guess we are thankful for the remaining 0.01% then.

The difference between x3220 and x3210 is x0010, which is #16. Since PC is incremented in the FETCH stage, and the target address is generated later, the offset is #15, which is what the answer sheet said.

Good luck with the final exam.

Yale Patt