| Word or
Term |
Description or
Explanation |
| I/O |
Input/Output |
| I/O podule |
Acorn's (dual width) interface card that
provides RISC OS computers with some of the many interface facilities that were
standard on the BBC Micro range of computers - interfaces include user port,
parallel port, analogue post and 1MHz bus |
| ICA |
Independent Computing Architecture (Citrix
Systems) - previously called Intelligent Console Architecture |
| ICMP |
Internet Control Message Protocol - a protocol
used on the Internet to send control information, e.g. ping uses this to send
an "Echo_Request" |
| Iconbar |
the strip along the bottom of the computer
screen that contains icons for devices (to the left) and applications (to the
right) that are currently available to the user |
| Icons |
small pictures representing devices, files,
directories, applications, etc. |
| IDC |
Insulation Displacement Connector - this refers
to a connector where the connection between the contacts and the individual
wires is made by squeezing a row (or usually two rows) of sharp metal teeth
onto a ribbon cable so that the teeth cut into the insulation and make contact
with each individual wire |
| IDE |
Integrated Drive Electronics - an electronic
standard method of connecting one or two hard drives to a computer system - the
standard was set up to provide a simpler and cheaper means of connecting hard
drives to IBM and compatible computers than was currently available |
| IDTV |
Integrated digital television - the set-top box
technology is integrated into the casing of a television casing to eliminate
the need for a separate receiver decoder |
| IEEE488 |
an interface standard for connecting scientific
instruments to computers as agreed by the Institute of Electrical and
Electronic Engineers (USA) - 488 is the number of the document - usually called
IEEE interface, but also HPIB and GPIB for Hewlett Packard ..... and General
Purpose ...., originally designed by HP - it is an 8-bit data bus, allowing up
to 16 devices to be addressed, with handshake and interrupt lines - Intelligent
Interfaces make a very good IEEE interface for the RISC OS computers, but it
won't work with the Acorn Unix boxes because of interrupt latency |
| IIC or I2C |
Phillips' proprietary 2-wire serial bus
interface - one wire is a clock and the other carries serial data - used
internally in Archimedes computers for the real time clock and the CMOS RAM -
difficult to use externally because of buffering problems (it is very difficult
to buffer a bidirectional line) - IIC is used in TVs and radios, HiFis
etc. |
| Image processing |
if an image is stored on a computer as binary
data (such as a sprite file) it is possible to manipulate the data
mathematically to enhance, distort, translate or otherwise modify the picture
in controlled ways |
| IMAP |
Internet Mail Access Protocol - this is a
networking protocol which allows users to manipulate and read the contents of
mail folders held on a remote server - unlike with the POP protocol, the mail
continues to reside on the remote machine - this approach has advantages in an
environment where users move from machine to machine so that transferring an
individual's mail to a particular client machine would not be appropriate - the
protocol is formally specified by Internet RFC 1176 - there is a good document
which describes these which you can get from
ftp://ftp.cac.washington.edu/mail/imap.vs.pop |
| Inkjet printer |
this is a type of printer where the patterns on
the paper are generated by squirting ink through a series of tiny nozzles in
the print head |
| Input focus |
the input received from the keyboard can be
directed to one and only one window at a time - the window currently receiving
information from the keyboard is said to have the input focus - this is
indicated by the title bar of the window changing from grey to yellow |
| Intel Corporation |
a major manufacturer of microprocessors for
PCs, e.g. the 80286-80486 range and their proprietary Pentium/Pentium II |
| Interlace |
build up a picture on a monitor screen using
two passes, each displaying alternate lines, the aim being to reduce flicker
effects |
| Internet |
an interconnected network of networks - the
Internet exists purely as a large group of machines that pass messages to each
other, sites linking themselves in because they found it useful - remember when
using the Internet that you are piggy backing on other peoples efforts and
paying nothing for it, so be polite because they could easily decide to stop
passing your messages through - there is no one organising it and hence no one
to complain to if you don't like it - the Internet is probably the world's most
successful anarchy! |
| Internet address |
see IP
address |
| Internet Explorer |
a browser developed by Microsoft to compete
with Netscape's Navigator, and its methods of distribution have led to some
charged confrontations between Microsoft and the US Department of Justice |
Internet Protocol
Suite |
the set of protocols which includes TCP, UDP
and IP - it is also often (misleadingly) referred to as TCP/IP - originally
developed in the 1970s and early 1980s by the U.S. Defense Advanced Research
Projects Agency for the Arpanet, precursor of the Internet |
| Interpreter |
a program that converts each instruction of a
high level language such as Basic into executable machine code line by line, as
the program in the high level language proceeds (see
Compiler for more explanation) - every
RISC OS computer contains a Basic interpreter |
| IOC |
Input/Output Controller - the I/O chip used on
pre-RiscPC Acorn computers was called IOC |
| IOMD |
Input Output Memory Device - this is a computer
chip designed by ARM Ltd which allows ARM processors to control input/output
devices and to access memory |
| IP (1) |
Internet Protocol - the network protocol
responsible for passing data packets from one host to another - each packet
contains the IP address of both the source and destination hosts - IP is
regarded as unreliable because individual packets may get lost as they wander
around the Internet - hence TCP is usually to control it if reliability is
important |
| IP (2) |
Information Provider - a company that provides
Internet access on a commercial basis |
| IP address |
a unique 32-bit address assigned to a host
connected to the Internet (usually this is a static allocation, but some
dial-up Internet providers assign IP addresses dynamically when you log on.) -
the IP address is usually presented in dotted-decimal format (e.g.
123.45.67.89), where each number represents eight bits of the address - the
first part of the address is assigned exclusively to an organisation by the
Network Information Center (NIC) in the United States - the use of the
individual addresses within this address space is then devolved to the
organisation itself |
| IRC |
Internet Relay Chat - a service operated on
certain hosts which allows multi-party online conversations - it allows users
to 'chat', by typing text, in real time - it is the Internet equivalent of CB
radio - the user runs an IRC client and connects to an IRC server using a
command such as /server stork.doc.ic.ac.uk - heshe then selects a
particular channel with /join #channel or similar |
| IrDA |
Infrared Data Association, Walnut Creek, CA,
http://www.irda.org - a membership organization founded in 1993 and dedicated
to developing standards for wireless, infrared transmission systems between
computers - with IrDA ports, a laptop or PDA can exchange data with a desktop
computer or use a printer without a cable connection - IrDA requires
line-of-sight transmission like a TV remote control - IrDA products began to
appear in 1995 - the LaserJet 5P was one of the first printers with a built-in
IrDA port
IrDA is comprised of the IrDA Serial IR physical layer (IrDA-SIR),
which provides a half-duplex connection of up to 115.2 Kbps - this speed allows
the use of a low-cost UART chip; however, higher non-UART extensions for 1.15
and 4 Mbps have also been defined - IrDA uses the Infrared Link Access Protocol
(IrLAP), an adaptation of HDLC, as its data link protocol - the Infrared Link
Management Protocol (IrLMP) is also used to provide a mechanism for handshaking
and multiplexing of two or more different data streams simultaneously |
| IRDA port |
Infra-red Data Association port - a wire-less
method of high-speed, line of sight, data transmission over short range |
| ISA Bus |
Industry Standard Architecture - this is a
'standard' expansion interface as used on PC compatibles (also referred to as
the AT bus?) |
| ISDN |
Integrated Services Digital Network - a high
speed network available in most European countries and the USA/Canada - it
combines voice and data transfer through a single medium |
| ISO |
International Standards Organisation - they
validate Pascal |
| ISP |
Internet Service Provider |