Harvard vs. vonNeuman

[Jim Battle]

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

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