PDP-7

PDP-7 - a piece of hardware that introduced many colleges to more affordable, usable, and reliable "mini-computers", i.e. computers that were only size of a few refrigerators instead of filling an entire room.

Thanks to Living Computer Museum for helping preserve a rare piece of hardware.

Additional background at wikipedia.

Another example from Columbia University.

A hardware specific site from Sometron, including a list of each machine and its operator.

The PDP-7 was the machine used to develop the UNIX operating system - software which has outlasted the hardware.