HP-IL
Encyclopedia
The HP-IL was a short-range interconnection bus or network introduced by Hewlett-Packard
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...

 in the early 1980s. It enabled several devices such as printers, floppy disk drives, tape readers, etc. to be connected to programmable calculators such as the HP-41C, HP-71B
HP-71B
The HP-71B was a hand-held computer or calculator programmable in BASIC, made by Hewlett-Packard from 1984 to 1989.The HP-71B was known as the "supreme" hand-held calculator/computer of choice at the time for those seeking the ultimate in hand-held devices. It was particularly popular at The...

 and HP-75C/D
HP-75
The HP-75C and HP-75D were hand-held computers programmable in BASIC, made by Hewlett-Packard from 1982 to 1986.The HP-75 had a single-line liquid crystal display, 48 KiB system ROM and 16 KiB RAM, a comparatively large keyboard , a manually operated magnetic card reader , 4 ports for memory...

, the 80-series
HP series 80
The Hewlett-Packard series 80 of small scientific desktop computers was introduced in 1980, beginning with the popular HP-85 targeted at engineering and control applications. They provided the capability of the HP 9800 series desktop computers in a smaller package including storage and printer, at...

 and HP-110 computers, as well as generic ISA bus based PC
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...

s.

Principles

The HP-IL can be seen as a precursor to the Universal Serial Bus
Universal Serial Bus
USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....

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

The IL used a form of Token passing
Token passing
In telecommunication, token passing is a channel access method where a signal called a token is passed between nodes that authorizes the node to communicate. The most well-known examples are token ring and ARCNET....

 protocol for media access control.

Every device on the bus has a ring-in and a ring-out connector, either on pigtails or built in. HP used a proprietary two-pin connector design with polarizing "D"-shaped shells. HP-IL cables can be interconnected without further adapters to extend their length.

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/HP-IB Interface, HP-IL controllers could be connected to instruments with an HP-IB (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
RS-232
In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...

 and general-purpose parallel I/O interfaces as well as a prototype kit to create custom interfaces.

Controllers

  • HP 82160A HP-IL HP-41 extension module
    HP-41 extension module
    HP-41 extension modules allowed the user of a HP-41 programmable calculator to extend the functionality of the machine. The HP-41 had room for up to four expansion modules at the back of calculator....

     (for the HP-41C)
  • HP 82973A HP-IL interface for IBM PC and compatibles with ISA bus
  • HP 82938A Interface for Series 80
    HP series 80
    The Hewlett-Packard series 80 of small scientific desktop computers was introduced in 1980, beginning with the popular HP-85 targeted at engineering and control applications. They provided the capability of the HP 9800 series desktop computers in a smaller package including storage and printer, at...

     desktop computers/controllers
  • HP 82401A HP-IL module for HP-71B
    HP-71B
    The HP-71B was a hand-held computer or calculator programmable in BASIC, made by Hewlett-Packard from 1984 to 1989.The HP-71B was known as the "supreme" hand-held calculator/computer of choice at the time for those seeking the ultimate in hand-held devices. It was particularly popular at The...

  • HP-75C/D
    HP-75
    The HP-75C and HP-75D were hand-held computers programmable in BASIC, made by Hewlett-Packard from 1982 to 1986.The HP-75 had a single-line liquid crystal display, 48 KiB system ROM and 16 KiB RAM, a comparatively large keyboard , a manually operated magnetic card reader , 4 ports for memory...

  • HP-110
  • HP-150
    HP-150
    The HP-150, a "compact, powerful and innovative" computer made by Hewlett-Packard in 1983 and based on the Intel 8088, was one of the world's earliest commercialized touch screen computers. The machine was not IBM PC compatible, although it was MS-DOS compatible. Customized MS-DOS versions 2.01,...


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)
  • HP 82985A HP-IL/NTSC (monochrome)

Peripherals

  • HP 9114A/B Disc Drives
  • HP 82161A Tape Drive
  • HP 82162A Thermal Printer (HP-IL version of HP 82143A printer for HP-41C)
  • HP 82163A Video Interface
  • HP 92198A 80-Column Video Interface (Mountain Computer)
  • HP 82168A, 92205M Acoustic Couplers (Modems)
  • HP 82905A/B Printers
  • HP 2225B ThinkJet Printer
  • HP 7470A Graphics Plotter (Opt. 003 HPIL Interface)
  • HP 2671A/G Alphanumeric Graphics Thermal Printer

Test instruments

  • HP 1630 and HP1631 Logic analyzer
    Logic analyzer
    A logic analyzer is an electronic instrument which displays signals in a digital circuit. A logic analyzer may convert the captured data into timing diagrams, protocol decodes, state machine traces, assembly language, or correlate assembly with source-level software.Presently, there are three...

    s (can be loop controller)
  • HP 3421A Data Acquisition/Control Unit
  • HP 3468A/B Digital Multimeters (HP-IL version of HP 3478A with GPIB)
  • HP 5384A and HP 5385A frequency counters with option 003 (HP-IL)
  • HP 8590A spectrum analyzer with option 022 (HP-IL)

Software

  • HP-IL Development Module (plug-in Application ROM module for HP-41C)
  • HP 82183A Extended I/O Module

See also

  • IEEE-488 (GPIB,HPIB)
    IEEE-488
    IEEE-488 is a short-range digital communications bus specification. It was created for use with automated test equipment in the late 1960s, and is still in use for that purpose. IEEE-488 was created as HP-IB , and is commonly called GPIB...

  • Apple Desktop Bus
    Apple Desktop Bus
    Apple Desktop Bus is an obsolete bit-serial computer bus connecting low-speed devices to computers. Used primarily on the Macintosh platform, ADB equipment is still available but not supported by most Apple hardware manufactured since 1999....

  • Universal Serial Bus
    Universal Serial Bus
    USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....


External links

  • http://www.hpmuseum.org
  • http://www.hp41.org/HPIL.cfm
  • http://www.hp-collection.org/hpil.html
  • http://www.jeffcalc.hp41.eu/hpil/ A homebrew HP-IL to USB/EIA-232 bridge.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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