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 Architecure... My question is - was there tension around Harvard and Von Neumann architectures in Unix circles and if so, how was it resolved? Thanks, Will -- GPG Fingerprint: 68F4 B3BD 1730 555A 4462 7D45 3EAA 5B6D A982 BAAF