The last time I taught assembly language programming, I decided to include the PDP-11 as an example of addressing modes. This is because Patterson and Hennesey just use MIPS --- it's a good pedagogical method but then when the students hit the real world they wouldn't know an address mode from ??? I also had them think about the VT-40 as an example --- I thought they would like that kind of graphical machine (I was wrong of course). If I was more prepared and had a full graphical simulator, that would have helped.