HP-IL
From Wikipedia, the free encyclopedia
| HPIL (Hewlett-Packard Interface Loop) | ||
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| Type | Peripheral data bus | |
| Production history | ||
| Designer | Hewlett-Packard | |
| Designed | 1980s | |
| Manufacturer | Hewlett-Packard | |
| Superseded | IEEE-488 | |
| Superseded by | Apple Desktop Bus, USB (mid 1990s) | |
| Specifications | ||
| External | yes | |
| Data signal | Token ring | |
| Bandwidth | 160 kbit/s (limited to 16 kbit/s) [1] |
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| Max devices | 31 (with extensions up to 960) |
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| Protocol | Serial | |
| Pins | 2 | |
The HP-IL (Hewlett-Packard Interface Loop) was a short-range interconnection bus or network introduced by Hewlett-Packard 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 and HP-75C/D, the 80-series and HP-110 computers, as well as generic ISA bus based PCs.
Contents |
[edit] 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 controllers (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.
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.
[edit] 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 and general-purpose parallel I/O interfaces as well as a prototype kit to create custom interfaces.
[edit] Equipment with HP-IL Interface
[edit] Controllers
- HP 82160A HP-IL Module for the HP-41C
- HP 82973A HP-IL interface for IBM PC and compatibles with ISA bus
- HP 82938A Interface for Series 80 desktop computers/controllers
- HP 82401A HP-IL module for HP-71B
- HP-75C/D
- HP-110
- HP-150
[edit] 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)
[edit] 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
[edit] Test instruments
- HP 1630 and HP1631 Logic analyzers (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)
[edit] Software
- HP-IL Development Module (plug-in Application ROM module for HP-41C)
- HP 82183A Extended I/O Module
[edit] Third-party
- FSI164A HP-IL/RS-232C Interface
- Leitz IL-41 Theodolite interface
[edit] 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
