- PC - Buzz - 1 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z *

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HAA = Home Automation Alliance

The HAA is an alliance of manufacturers, dealers and technology developers focused on the development and proliferation of integrated home systems, including automation, structured wiring, communications networks and various subsystems such as lighting control, entertainment, telecommunications and security.
 

www.homeautomation.com

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Hacking

Den oprindelig (rigtige) betydning af en Hacker er:

En dygtig programmør
En, som kender et/flere operativsystemer til bunds
En, som er ekspert i et programmerings-sprog/system

Et godt hack er en god løsning på et problem. Hacking er dét, at udføre handlingen.
Eric Raymond, som har skrevet The New Hacker's Dictionary foreslår, at man bruger termen Cracker i stedet for Hacker.
I starten af 80'erne var en Cracker en person, der brød kopibeskyttelse på spil. Derfor passer beskrivelsen også på en computer-indbrudstyv. Han bryder kopibeskyttelsen (password) og bruger programmet (systemet) som han lyster.
De rigtige Hackere kan ikke udstå Crackere og deres handlinger, og vil derfor helst ikke blandes sammen med dem.

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HAL = Hardware Application Layer, Hardware Abstraction Layer

Encapsulates platform-dependent code - HAL.DLL in Windows NT - the equivalent of the IO.SYS BIOS in DOS
So applications may run unchanged on different platforms (portability).
Vendors create additional HALs for new processors

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HAVi = Home Audio Video interface

A Sony initiative, the HAVi is an application-layer API for 1394 networks, and supports proprietary languages such as as the AV/C command language.
 

www.havi.org/home.html

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Hayes

www.sci.muni.cz/docs/pc/trm.txt : Hayes Modem Technical Reference

> Hayes AT-kommandoer

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HCL = Hardware Compatibility List

Microsofts liste over testede hardware-komponenter, som understøttes af Windows NT/2000/XP.
 

www.microsoft.com/hwdq/hcl/search.asp
www.microsoft.com/hwtest/hcl
www.microsoft.com/isapi/hwtest/hcl.idc
www.microsoft.com/ntserver/nts/techdetails/default.asp
ftp://ftp.microsoft.com/services/whql/win2000hcl.txt

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HDLC = High-level Data Link Control

A bit oriented, synchronous data-link (layer 2) protocol adopted by ISO.
Messages are transmitted in frames with differing amounts of data.
HDLC is an international standard developed in the 1970's to provide simple, reliable modem communications. Like all international standards, it has a very broad definition with something for everyone.
The HDLC definition leaves open many choices. Communication can be full-duplex (where both computers can send data to each other at the same time) or half-duplex (where one computer sends and the other listens). When a sequence of data packets arrives and one is found to be in error, the receiver can either ask specifically for the one bad packet to be retransmitted, or it can ask for that packet and all the data that followed it to be retransmitted.
In an HDLC or IEEE 802 connection, data is transferred as numbered Information units called I-frames. When the connection is established, the two computers agree on the number of I-frames ("the window") that each can send before waiting for some of the outstanding data to be acknowledged. In each I-frame, and in a separate control packed used when there is no pending data (Receiver Ready or "RR") each computer announces the number of the next I-frame it expects to receive. By indicating that it is ready to receive frame 6, the computer implicitly acknowledges that frame 5 arrived and was processed correctly. A station should be able to accept the number of frames in the agreed window, but memory is unexpectedly short it can stop the flow of data with a Receiver Not Read ("RNR") control message.
It is possible to detect and recover from all communications errors using just I-frames and the two control packets RR and RNR. This makes HDLC a very simple but powerful protocol. Additional control packets are defined as options to improve efficiency, but their use is not required.
> ABM, DLC, SDLC, SNA

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HDSL = High rate Digital Subscriber Line

> DSL

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hexadecimal

I det 'hexadecimale talsystem' er grundtallet 16: hvert ciffer har 16 mulige værdier: 0, 1, ..., 9, A, B, C, D, E, F.

(I det 'decimale talsystem' er grundtallet 10: hvert ciffer har 10 mulige værdier: 0, 1, ..., 9)
 
Hexadecimale tal benyttes især til at angive værdien af computerdata, som er baseret på det binære talsystem
- hver bit har 2 mulige værdier: 0 og 1
- 4 bits har 2⁴=16 mulige værdier: 0..15 i det decimale talsystem - eller 0..F i det hexadecimale talsystem.
En  byte (8 bits) kan antage 2⁸=256 værdier: 0..255 i det decimale talsystem - eller: 0..FF i det hexadecimale talsystem (2⁸ = 2⁴ * 2⁴)

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hjemmeside

- benyttes i to betydninger:

1. En side på Internettet = webside.
2.  

   Startsiden til flere websider - den side man får, når man i browseren blot skriver webserverens adresse.

>HTML

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HMA = High Memory Area

64 KB RAM-område i extended memory lige over de underste 1 MB RAM.
I real-mode (DOS) systemer giver HIMEM.SYS adgang til dette område, som oftest benyttes af DOS selv (DOS=HIGH i CONFIG.SYS).

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Home API

A standard application programming interface (API) that would allow developers to write home control programs around a single Microsoft Windows-based platform. The API is expected to be finalized this year, with compliant products available in 2000.

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Home PNA = Home Phoneline Networking Alliance

The Home-PNA has developed an Ethernet-like specification for existing telephone wiring based on technology from Tut Systems. HomePNA PC-networking products are available now.
> PNA
 

www.homepna.org
3Com: Home Phoneline Networking Alliance Embraced By Technology Industry

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Host

En computer i et netværk

 

Host Adress

Den del af en Internet Adresse som specificerer en bestemt computer (vært) - tildeles af lokal domæne administrator
> Domain

 

Host Table

primitive Name Resolution when DNS and WINS is not used - a manually maintained text file called HOSTS (in \Windows\) contains a list of IP-addresses and associated host names in this format:

192.0.3.30	PC0 

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Host-On-Demand

IBM eNetwork On-Demand Server

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HOSTS

[Techweb] A text file in a UNIX network that provides name resolution of host names to IP addresses. HOSTS files, which contain host names and IP addresses, are manually updated and replicated onto all the servers in the enterprise. Except in small networks, HOSTS files have given way to the DNS system.
> DNS, LMHOSTS

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HotBot

search engine
 

www.hotbot.com

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HP-UX

Hewlett-Packard UNIX

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HPFS = High Performance File System

- in IBM OS/2

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HRD = Human resource development

The integrated use of personnel training and development, organization development, and career development to improve individual, group, and organization effectiveness in fulfilling the vision of the institution.

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HSB = Hue, Saturation, Brightness

En 'subjektiv' farvemodel
Hue : farvetone : rød-orange-gul-grøn-blå-violet
Saturation : mætningsgrad, farveintensitet
Brightness :

> CMYK, RGB

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HSCSD = High Speed Circuit Switched Data

HSCSD kaldes også High Speed Data. Benyttes til mobiltelefoni. Giver trådløst adgang til et netværk, og giver høj kredsløbskoblet datahastighed ved at kombinere flere timeslots. En normal talesamtale benytter et timeslot - dvs. 9,6 Kb/s. Med to timeslots fås en hastighed på 19,2 Kb/s. Dog kan nyere terminaler udnytte hastigheder op til 14,4 Kb/s per timeslot.

 

[TechEncyclopedia]: An enhancement to the GSM mobile communications system that enables up to four 14.4 Kbps channels to be combined to provide 57.6 Kbps data transfer. Part of GSM Phase 2, HSCSD is suited for videoconferencing and multimedia transmission.

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HST

US Robotics modem transmissions protokol - 14400, 16800, 19200 og 21600 bps

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HTA = HyperText Application

En applikation skrevet i HTML med script, som fortolkes og afvikles i fx Internet Explorer.
>Hypertext

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HTML = HyperText Markup Language

A subset of SGML - Invented by Tim Berners-Lee, maintained by the IETF Working Group on HTML
 

[w3.org]: HTML is the lingua franca for publishing hypertext on the World Wide Web. It is a non-proprietary format based upon SGML, and can be created and processed by a wide range of tools, from simple plain text editors - you type it in from scratch- to sophisticated WYSIWYG authoring tools. HTML uses tags such as <h1> and </h1> to structure text into headings, paragraphs, lists, hypertext links etc

 

Det kodesprog som Internettes websider er skrevet i - transporteres på Internettet med protokollen HTTP.
>Webserver

 

> HTML koder ('tags')
 

www.w3.org/MarkUp/MarkUp.html : W3C's HyperText Markup Language Home Page
info.uibk.ac.at/info/kurs/htmlkurs/htmlref/ : Sandia HTML Reference
html.about.com/mbody.htm
www.ics.usi.edu:80/pub/ietf/html/

>DHTML, DTD, HTA, Hypertext, MHTML, SGML, VRML, XHTML, XML

 

HTML 2.0

HTML 2.0 (RFC 1866) was developed by the IETF's HTML Working Group, which closed in 1996. It set the standard for core HTML features based upon current practice in 1994.
 

www.w3.org/MarkUp/html-spec/
www.w3.org/MarkUp/html-spec/html-spec_toc.html

HTML 3.0

www.w3.org/MarkUp/html3/ : HTML 3.0 Draft (Exprired!) Materials

HTML 3.2

W3C's recommendation for HTML which represented the consensus on HTML features for 1996. HTML 3.2 added widely-deployed features such as tables, applets, text-flow around images, superscripts and subscripts, while providing backwards compatibility with the existing HTML 2.0 Standard.
 

www.w3.org/TR/REC-html32 
www.w3.org/MarkUp/Wilbur/ : Introducing HTML 3.2

HTML 4.0

First released as a W3C Recommendation on 18 December 1997. A second release was issued on 24 April 1998 with changes limited to editorial corrections. This specification has now been superseded by HTML 4.01.
 

www.w3.org/TR/1998/REC-html40-19980424  

HTML 4.01

The HTML 4.01 Recommendation released on 24th December 1999 fixes a number of bugs in the HTML 4.0 specification.
 

www.w3.org/TR/html4
www.w3.org/TR/REC-html40/ : HTML 4.01 Specification

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HTTP = Hyper Text Transfer Protocol

Protokol som på Internettet benyttes til transport af HTML-dokumenter.
Indeholdt i protokol-suiten TCP/IP.
Benytter IP-port 80.
 
> SHTTP, HTTPS, URL

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HTTPS = HTTP Secure

Netscape variant of HTTP running over SSL - with encryption and transmission through secure port.
> SHTTP

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hub

Kabelkoncentrator. Opererer på lag 1 (det fysiske) i OSI-modellen. Ingen intelligens - forstår ikke MAC-adresser.
En passiv hub forbinder blot kabel-segmenter.
En aktiv hub gendanner hver bit inden den sendes videre - kaldes også multiport repeater.
 

[IT-Lex]: Fra engelsk: hjulnav. I lokalnet betegner en hub en central tilkoblingsenhed, hvortil flere arbejdsstationer tilkobles via punkt-til-punkt forbindelser. Ligesom egerne i et hjul samles i hjulnavet, så samles de forskellige tilkoblinger i en hub. Hubs anvendes således i stjerneformede topologier. Alternativt til arbejdsstationer kan andre hubs tilkobles en central hub, hvilket resulterer i en træformet topologi.
Hubs kan udformes som passive hubs, der principielt blot forbinder de enkelte tilslutningskabler med hinanden. Endvidere findes aktive hubs, der indeholder elektronik og forstærkere, som elektrisk isolerer tilslutningerne fra hinanden. Dette giver mulighed for større kabelafstande.

 

[MS-CD]: In a network, a device joining communication lines at a central location, providing a common connection to all devices on the network. The term is an analogy to the hub of a wheel.

 

active hub
[MS-CD]: 1. The central computer that regenerates and retransmits all signals in an active star network.
2. A type of hub used on ARCnet networks that both regenerates (boosts) signals and passes them along.

intelligent hub

passive hub

switching hub

 

> MAU, switch

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hukommelse

>RAM, ROM

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hybridnet

Landsdækkende netværk, som skal distribuere TV-signaler til antenneforeninger - sammensat af forskellige transmissionsmedier: kobberkabler og lysledere ('hybrid' betyder 'bastard' eller 'krydsning').
>bredbånd

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hyperlink

Tekst eller billede med en skjult kode, som aktiveres med et museklik. Koden angiver adressen på en anden tekst.
>hypertext

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hypertext

Tekst med aktive links (hyperlinks), som ved klik springer til et andet sted - enten i samme dokument eller i et andet dokument. Hypertekst findes på Internettets web-sider og i fx Hjælp-teksterne, som følger med Windows og mange programmer.

>HTA, HTML

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Hz = Hertz

enheden for 'frekvens' - d.v.s "et-eller-endet" pr sekund
>spectrum