Harvard vs. vonNeuman

[Paul Koning]

>>>>> "Jim" == Jim Battle <frustum at pacbell.net> writes:

 Jim> I month or so ago I prattled on about what I recalled about the
 Jim> BTI Computer Systems architecture, where I worked for a year
 Jim> back in 85/86.

 Jim> That machine had an instruction to execute an instruction that
 Jim> was held in a register!  Kind of like the perl exec() function,
 Jim> for one instruction.  I imagine it could have been useful for
 Jim> single stepping and other debugging operations.

So did the PDP-10, back in the 1970s (and, probably, the PDP-6 -- mid
1960s.)  Somewhat useful for stepping, though a "single step"
processor flag (as in the PDP11) is better because it covers branches
too. 

     paul