The Hewlett-Packard Instrument Bus (HP-IB), is a short-range digital communications standard developed by Hewlett-Packard (HP) in the 1970s for connecting electronic test and measurement devices (e.g. digital multimeters and logic analyzers) to controllers such as computers. The bus is still in wide use for this purpose.
Other manufacturers copied HP-IB, calling their implementation the General Purpose Interface Bus (GPIB). In 1978 the bus was standardized by the Institute of Electrical and Electronics Engineers as the IEEE Standard Digital Interface for Programmable Instrumentation, IEEE-488-1978 (now 488.1).
IEEE-488 allows up to 15 devices to share a single bus by daisy-chaining, with the slowest device participating in the control and data transfer handshakes to determine the speed of the transaction. The maximum data rate is about one megabyte per second. Paraphrasing the 1989 HP Test & Measurement Catalog: HP-IB has a party-line structure wherein all devices on the bus are connected in parallel. The 16 signal lines within the passive interconnecting HP-IB cable are grouped into three clusters according to their functions: Data Bus, Data Byte Transfer Control Bus, and General Interface Management Bus.