NCR 315

The main processor includes three cabinets and a console section that houses the power supply, keyboard, output writer (an IBM electric typewriter), and a panel with lights that indicate the current status of the program counter, registers, arithmetic accumulator, and system errors.Input/Output is by direct parallel connections to each type of peripheral through a two-cable bundle with 1-inch-thick cables.[3] The 315-100 series console I/O incorporates a Teletype printer and keyboard in place of the original 315's IBM typewriter.The primary difference between the older NCR 315 and the 315-100 was the inclusion of the Automatic Recovery Option (ARO).One of the problems with early generation of computers was that when a memory or program error occurred, the system would simply turn on a red light and halt.