The system was originally conceived as building blocks for solid-state hard-wired programmed logic controllers (the predecessors of programmable logic controllers (PLC)) to replace electro-mechanical relay logic in industrial control systems for process control and automation applications, similar to early Telefunken/AEG Logistat, Siemens Simatic, Brown, Boveri & C, ACEC Logacec or  Estacord systems.
Each available logical function was recognizable by the color of its plastic container, black, blue, red, green, violet, etc. The most important circuit block contained a NOR gate (hence the name), but there were also blocks containing drivers, and a timer circuit similar to the later 555 timer IC.
The original Norbit modules of the YL 6000 series introduced in 1960 had potted single in-line packages with up to ten long flying leads arranged in two groups of up to five leads in a row. These modules were specified for frequencies of less than 1 kHz at ±24 V supply.
Also available in 1960 were so called Combi-Element modules in single-in line packages with ten evenly spaced stiff leads in a row (5.08 mm / 0.2-inch pitch) for mounting on a PCB. They were grouped in the 1-series (aka "100 kHz series") with ±6 V supply. The newer 10-series and 20-series had similarly sized packages, but came with an additional parallel row of nine staggered leads for a total of 19 leads. The 10-series uses germanium alloy transistors, whereas in the 20-series silicon planar transistors are used for a higher cut-off frequency of up to 1 MHz (vs. 30 kHz) and a higher allowed temperature range of +85 °C (vs. +55 °C).
In 1967, the Philips/Mullard NORBIT 2 aka Valvo NORBIT-S family of modules was introduced, first consisting of the 60-series for frequencies up to 10 kHz at a single supply voltage of 24 V, only. Later, the 61-series, containing thyristor trigger and control modules, was added. A 90-series became available in the mid-1970s as well. There were three basic types contained in a large (one by two inch-sized) 17 pins dual in-line package, with nine pins spaced 5.08 mm (0.2-inch) on one side and eight staggered pins on the other side.