IBM 1800 Data Acquisition and Control System

The IBM 1800 Data Acquisition and Control System (DACS) was a process control variant of the IBM 1130 with two extra instructions (CMP and DCM), extra I/O capabilities, 'selector channel like' cycle-stealing capability and three hardware index registers.

IBM announced and introduced the 1800 Data Acquisition and Control System on November 30, 1964, describing it as "a computer that can monitor an assembly line, control a steel-making process or analyze the precise status of a missile during test firing.".

Unlike the 1130, which was a desk-like unit, the 1800 is packaged in 6 foot high, EIA Standard 19 inch racks, which are somewhat taller than the racks used by S/360 systems of the same vintage, but the internal gates and power supplies were very much the same. Many 1800 cabinets show a distinct "ding" on the vents at the top of the chassis, where movers discovered that the door into a computer room was not quite tall enough for the 1800 cabinet.