A PACX Box

PACX Terminal Connection Diagram
From CUCCA Newsletter, circa 1978; CLICK to magnify.

PACX Box    A little blue box like this was next every terminal on the Columbia University campus (except those connected directly to departmental minicomputers or modems) from 1977 until 1988. The box was hardwired back the Gandalf PACX IV crossbar switch in the machine room, which in turn was wired to the various central computers. Two little thumbwheels allowed you to choose the desired service (PDP-11, DEC-20, IBM mainframe). A great deal of confusion arose because of the different terminal settings required to access the different hosts, and the difficulty in reconfiguring the terminals -- anything ranging from DIP switches to buttons and dials to on-screen setup modes. Terminals in public areas were often left in some strange configuration to "reserve" them for later use.

In 1988 the PACX was replaced by the IBM/Rolm CBX, a digital voice telephone system for the Morningside campus that also provided serial-port connections through data connectors on the back of the phone. In 1999, by which time Ethernet (on the same Rolm wiring) was ubiquitous, Rolm serial data connections were discontinued.

Also see: Sample page from CUCCA Terminal and Plotter User Guide (1982).


Frank da Cruz / fdc@columbia.edu / Columbia University Computing History