Retrospective: What Have We Learned from the PDP-11

I put in the post title the original name of this fascinating article written by Gordon Bell. 

My favourite quote:

We had a basic understanding of Moore’s Law, but unfortunately when we examined the implications for the future, the results were too radical to believe. It was hard to believe that the 780 timeshared system selling for $250,000 would sell for a maximum of $5,000 in less than 20 years

Moore’s Law suggests that one additional address bit is required every 18 months. It predicts that DRAM chip capacity increases 4x every 3 years. Thus, if memory chip prices are constant, and if users pay a constant amount for computers, then the memory capacity will grow by one address bit each 18 months. This argument ignores the workstation market for the lower priced constant-capacity computers that appeared under the $100K -$250K price umbrella that VAX initially targeted.