I just noticed that the 1972_stuff "as" program generates: 400 MOV #120000,SP for core = orig+40000 / specifies beginning of user's core ecore = core+20000 / specifies end of user's core (4096 words) [...] . = orig+400 / copy in transfer vectors mov $ecore,sp / put pointer to score in the stack pointer while the V7 assembler is generating the correct: 400: MOV #60000,SP I have no idea why it is doing this. The 1972_stuff "nm" program correctly lists ecore as 60000. Use the 1972_stuff "as" at your own risk! Tim Newsham http://www.thenewsh.com/~newsham/