A family of real-time computers from HP introduced in 1966 as the model 2116A. Several 2100 models were launched before the machines were given the HP 1000 series name in the 1970s. Running under the Real-Time Executive (RTE) operating systems, HP 1000s were sensor-based computers used extensively in laboratory and manufacturing environments for collecting and analyzing data. Discontinued in the 1990s, but still working after the turn of the century, the HP 1000 is perhaps the longest-running computer series on the market.