1975 - The PDP-11/70 represented the high end of PDP-11 architecture with the capacity for supporting the speed, addressing range and bandwidth required in large systems applications. It was the first PDP-11 to use cache memory.
The midrange PDP-11/34 was DIGITAL's most successful PDP-11 in terms of unit volume. The 11/34 featured a CPU so compact that the entire CPU logic was contained on two circuit boards. This provided greater flexiblity during later system expansion by making additional chassis space available