[TUHS] Harvard and Von Neumann Architectures and Unix

Will Senn will.senn at gmail.com
Sat Nov 25 05:25:18 AEST 2017

I am curious about how the Harvard Architecture relates to Unix, 
historically. If the Harvard Architecture is predicated on the 
separation of code from data in order to prevent self-modifying code (my 
interpretation), then it would seem to me to be somewhat at odds with a 
Unix philosophy of extreme abstraction (code, data, it's all 0's and 
1's, after all). In my naive understanding, the PDP-11 itself, with the 
Unibus and apparently agnostic ISA seem to summarily reject the Harvard 

My question is - was there tension around Harvard and Von Neumann 
architectures in Unix circles and if so, how was it resolved?



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