CS M-O words

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magnetic ink character recognition (MICR)

``The identification of characters through the use of magnetic ink. See also the definition of “OCR”. Dark black, strangely shaped letters at the bottom of personal checks. The ink is magnetic - the reader is NOT optical.

mainframe

A computer, usually in a computer centre, with extensive capabilities and resources to which other computers may be connected so that they can share facilities. Banks use mainframe computers to store customer accounts for millions of customers. Research labs use mainframes to do very complex calculations on large sets of data. NOT a PC

master file

A permanent file holding information that can be accessed and that is periodically updated by processing with a transaction file. See also the definition for “transaction file”. All the student data in a schools database. When a new student enrolls, or a student leaves, the database must be changed.

memory address register (MAR)

Holds the address in memory of the instruction at present being executed. also called the Program Counter

memory manager

A program that is usually part of the operating system that controls the allocation of memory to various applications. It is particularly important in multi-tasking systems where applications might otherwise cause conflicts, and for implementing virtual machines and virtual memory. Windows contains a memory manager - any MULTI-TASKING OS must contain a memory manager, but you cannot see it. NOT DOS - there is no memory manager - each program occupies the entire memory - this is a single-tasking system

memory mapped I/O

See the definition for “DMA”. Assigning PORT numbers or Interrupt numbers to peripheral devices. Direct memory access.

menu

A display of a list of optional facilities that can be chosen by the user in order to carry out different functions in a system. File, Edit, View menues in Windows apps

method

The behaviour or operation of an object. The procedure used by an object as specified within the object class. See also the definition for “method signature”. Normal methods are CALLED by the main program. The actionPerformed method in an AWT app is called automatically by Windows when a GUI event occurs. A Constructor is a special kind of method that only runs when the object is instatiated

method signature

The number and types of arguments of a method. Just the header line of the method, e.g. void boolean Search(String target)

MICR

See the definition for “magnetic ink character recognition”.

microprocessor

An integrated circuit incorporating the main components of a central processor. These circuits are used for microcomputers and small devices controlled by computer. pentium or AMD chip in a PC. Smaller CPUs, 6502 or Z80 , can be used as EMBEDDED processors to control simple operations in an engine, heater, photocopier, etc.

microwave transmission

A method of electronic communication that does not require cables. Transmitted by the big dishes (like satellite dishes) you see on top of a switching station. NOT cell phones (handies)

modem

An abbreviation for “modulator/demodulator”: a piece of electronic equipment that converts digital signals from a computer into audio signals that are transmitted over telephone lines, and converts them back again. US Robotics 56 K, you must "dial up" to use these. NOT DSL or ISDN, which transmit digital signals across the telephone wires

modular language

A language in which a complete program can be broken down into separate components (modules), each of which is to some extent self-contained. For example, the scope of variables can be limited to a module and does not extend through the entire program. See also the definition for “top-down design”. In Java, the use of separate CLASSES, as well as using METHODS inside each class, as well as LIBRARY classes (java.awt, java.io, etc Old languages like C were NOT modular - any program was just one long list of instructions.

modularity

One aspect of structured programming in which individual tasks are programmed as distinct sections or modules. One advantage is the ease with which individual sections can be modified without reference to other sections. see Modular Language

module

A self-contained subset of a program. method, class, ADT

modulo arithmetic

Arithmetic that uses the integer result and integer remainder of division as two separate entities. in Java, the % sign --> 23 mod 5 = 23 % 5 = 3

multi-tasking

A mode of operation that provides for concurrent performance, or interleaved execution, of two or more tasks. Running several different downloads at once, running IE and Word simultaneously and copying parts of a web-page into word, background printing at the same time as you are typing or surfing the web

multi-user system

A system that allows two or more people to use the services of a processor within a given period of time. NOT just a LAN, where service requests come at various times, but SIMULTANEOUS access, such as a printer with several PCs connected. A LAN game is actually a good example, where many users are constantly be served.

multi-processing

The simultaneous execution of two or more computer programs or sequences of instructions by a computer (parallel processing). "TRUE" Parallel processing requires multiple CPUs - not common in PCs, but pretty common in Sun Work Stations and larger servers.

nand

The output of “nand” is False only if all inputs are True, otherwise the output is True. The opposite of AND: 0 nand 0 = 1 0 nand 1 = 1 1 nand 1 = 0

network

Any set of interconnected computer systems that share resources and data. See also the definitions for “networking”, “local area network (LAN)” and “wide area network (WAN)”. LAN (intranet), World-Wide-Web (Internet)

networking

Making use of the services of a network. See also the definitions for “network”, “local area network (LAN)” and “wide area network WAN”). above

node

In the terminology of tree structures, each position in the tree is called a “node”. tree, Linked-List. Any device on a computer network that can be addressed so that it can be contacted by other computers. Client, Server, Router A “host” computer on a network. Work station

nor

The output of “nor” is True if all statements are False, False if at least one statement is True. The opposite of OR : 0 nor 0 = 1 0 nor 1 = 0 1 nor 1 = 0

not

The output of “not” for a statement P is True if P is False, False if P is True.

object

An object is a combination of data and the operations that can be performed in association with that data. Each data part of an object is referred to as a data member while the operations can be referred to as methods. The current state of an object is stored in its data members and that state should only be changed or accessed through the methods. Common categories of operations include: the construction of objects; operations that either set (mutator methods) or return (accessor methods) the data members; operations unique to the data type; and operations used internally by the object. A List-Box, which has PROPERTIES and METHODS

object-oriented programming (OOP)

An approach to programming in which units of data are viewed as active “objects” rather than the passive units envisioned by the procedural paradigm. JAVA is strictly object-oriented. Older languages, like C and BASIC, did not have objects, so they were not OO.

OCR

Optical character recognition (reader). Refers to the use of devices and software to “read” characters and translate them into ASCII characters for later processing. Applications of OCR include the scanning of printed documents to convert the text into digital ASCII text that can then be edited in word processors. Scan a newspaper, use OCR to change the text into a document format, and then edit the document using Word.

OMR forms

Optical mark and read forms. Answer sheets in the SAT exam (bubble in sheets)

on-line

when a user has access to a computer via a terminal. Surfing the web, printing in the computer lab NOT typing an essay at home without a modem or network

on-line processing (interactive)

Data processing in which all operations are performed by equipment directly under the control of a central processor, for example, airline reservations. Airline reservations, Automatic Teller Machines. NOT a robot controller, which does not involve a user

open systems interconnection (OSI)

A set of protocols allowing different types of computers to be linked together. Consists of 3 levels

operand

In an arithmetical expression, the operand is the data that is to be operated on. In A * B + 4 , the operands are A,B, and 4

operating system (OS)

Software that controls the execution of programs and that may provide services such as resource allocation, scheduling, input/output control, and data management. Windows, Linux, DOS, Mac OS

operator

A character or string of characters that designate an operation. See also the definitions for “binary operator” and “unary operator”. In A * B + 4 , the operators are * and +

operator precedence

In programming languages, an order relation defining the sequence of the application of operators within an expression. parentheses first , * before + , && before ||

or

The output of “or” is True if at least one input is True, otherwise the output is False. In Java || , 0 or 0 = 0 0 or 1 = 1 1 or 1 = 1

overflow

The generation of a quantity, as a result of an arithmetic operation, that is too large to be contained in the result location. See also the definition for “underflow”.