Information About

Hp-il




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PRINCIPLES


The HP-IL can be seen as a precursor to the Universal Serial Bus now largely in use on desktop computers. However, as its name implies, the cable formed a loop: the cable originated in the HP-IL extension module, ran through all connected devices, then came back to the module.

On the bus, devices could act as contollers (the calculators/computers) or slaves (the peripherals). Certain controllers like the HP-71 module or the HP82973A ISA interface could be acting as slaves as well, enabling a small network of calculators to be set up.

The IL used a form of Token Passing protocol for media access control.


APPLICATIONS


Hewlett-Packard developed a range of devices to be connected to the HP-IL, mostly peripherals such as printers and storage devices for calculators. Through the 82169A HP-IL/HPIB Interface, HP-IL controllers could be connected to instruments with an IEEE-488 (aka GPIB or IEEE-488) interface, or vice versa. There were also plans to make test equipment with IL interfaces, but apart from the somewhat popular 3468A multimeter, only a few devices were introduced before HP-IL itself became obsolete.

In addition to the HP-IB interface, HP also sold RS-232 and general-purpose parallel I/O interfaces as well as a prototype kit to create custom interfaces.


EQUIPMENT



Controllers



Interfaces

  • HP 82164A HP-IL/RS-232C Interface (serial port)

  • HP 82165A HP-IL/GPIO Interface (generic parallel port)

  • HP 82166A HP-IL Converter (smaller version of GPIO interface intended for embedded use)

  • HP 82166C HP-IL Converter Prototyping Kit

  • HP 82169A HP-IL/HPIB Interface (bidirectional)



Peripherals

  • HP 9114B Disc Drive

  • HP 82161A Tape Drive

  • HP 82162A Thermal Printer (HP-IL version of HP 82143A printer for HP-41C)

  • HP 82163A Video Interface

  • HP 92198 Mountain Computer 80-Column Video Interface

  • HP 82168A Acoustic Coupler (Modem)

  • HP 82905B Printer

  • HP 2225B ThinkJet Printer

  • HP 7470A Graphics Plotter

  • HP 2671A/G Alphanumeric Graphics Thermal Printer



Test instruments

  • HP 1630 and HP1631 Logic Analyzer s (can be loop controller)

  • HP 3421A Data Acquisition/Control Unit

  • HP 3468A Digital Multimeter (HP-IL version of HP 3478A with GPIB)

  • HP 5384A and HP 5385A frequency counter with option 003 (HP-IL)



Software

  • HP-IL Development Module (plug-in Application ROM module for HP-41C)

  • HP 82183A Extended I/O Module



Third-party

  • FSI164A HP-IL/RS-232C Interface



REFERENCES


  • Gerry Kane, Steve Harper, David Ushijima: THE HP-IL SYSTEM: An Introductory Guide to the Hewlett-Packard Interface Loop. ISBN 0-931988-77-2

  • HP Journal, January 1983 (Several articles about HP-IL and related products)

  • HP 82160A HP-IL Module Owner's Manual for the HP-41

  • HP 82401A HP-IL Interface Owner's Manual for the HP-71



EXTERNAL LINKS

  • http://www.hpmuseum.org

  • http://www.hp41.org/HPIL.cfm

  • http://www.hp-collection.org/hpil.html