Appendix Glossary M

In the left margin you will find links to the glossary categorised alphabetically. Some of the pages are quite long and may take a few moments to load if you use a modem. This glossary is always being updated.

Glossary - M

MAC - Stands for Media Access Controller. The MAC determines how a data packet is sent across the network, including the source and destination of the packet.

Macro - This is a program within a program which can carry out a preset complex function with the stroke of one or two keys. You can preset your name and address, for example, and then every time you need to use it, in a particular program, just hit the macro key that you already preset as your name and address, and it will be all printed out for you. Saves time!

Macro Virus - A computer virus that is found programmed as a macro, and embedded into a file document. The virus is designed to execute when the document is opened. Today, most viruses are macro viruses. A user can protect his computer by installing and periodically updating antivirus software.

Mail - Generic term for information transported on the Internet using one of the various mail protocols. Often used to distinguish mail from news.

Mail Bomb - An email containing a large file or files designed to jam an ISPs server and/or the recipient's mail program. Once a bomb is opened, depending on the size of the file it contains, it can take hours to load. With many ISPs, a user's
penalty for mail bombing is discontinuation of service.

Mailbox - A directory maintained in an ISP's server that stores email until a user downloads it. Email may be saved in both the ISPs server or in the users computer.

Mailing list - A topic-oriented conference like a USENET newsgroup except that the messages are distributed by private e-mail. Typically, the Internet user would subscribe to a list by sending e-mail to the Listserv. Messages in the group arrive in the users' mailbox, and posts and follow-ups are sent to the Listserv to be forwarded on to other members of the group.

Mainframe Computer - A large, stationary computer that requires space in an air conditioned room. Such machines are able to store massive amounts of data, support many users simultaneously, and run a wide variety of applications all at one time. Before home computers became available in the early 1980s, mainframes were the only computers. They were used by governments world-wide and large corporations. IBM and Unisys are the leading manufacturers of mainframe computers.

MAPI - (Messaging Application Programming Interface) A Microsoft email management system that allows different email applications to work in harmony and distribute mail.

Margin - The space surrounding a body of text in a word processing document. A user can easily set the margins for documents before each use or use the default settings of the application.

Marquee - Usually a line of scrolling text created with Dynamic HTML and Java applets displayed on a Web page. Some Web browsers will not support scrolling text.

Mask - In graphics, drawing, and paint programs the term takes on different meanings. In a draw program it means to partially obscure the view of an image by hiding it behind a hole or opening. In a paint program it is the isolation of an area so it cannot accept other images.

Math Coprocessor - A math coprocessor (aka: FPU, NPU, math-co) is a chip designed to perform floating point calculations very quickly. Sometimes the main processor does not include an onboard FPU in which case it executes floating point instructions very slowly compared to a FPU. 486 computers have the co-processor built in, while it must be added to a 386.

Maximise - In Macintosh and Windows operating systems, as well as many software programs, a button found in the upper right hand corner of the screen (in most cases, but not always) that, when the user places the mouse cursor on it and clicks, it enlarges the current window to fit the entire screen.

Mb - Megabit, sometimes written as Mbit. One Megabit is one-eighth of one Megabyte. Thus, 400 Mbps = 50 MB/sec.

MB - A megabyte (MB) is a measurement of units of memory or storage space on a computer. Each character, or keystroke, takes up one byte. Mega means million, so a megabyte is a million bytes. 1 MB = 1 Million Bytes (actually, 1,048,576 bytes). 1 KB = 1 Thousand Bytes, or 1 Kilobyte (1,024 bytes).

MDI - (Multiple Document Interface) A Windows interface program allowing programmers to write applications with many windows, with each application having a main window and a varying number of child windows. The child windows are shown inside of the main window. MDI is rapidly being replaced by a newer application program interface (API) called Single Interface Document (SDI).

MDRAM - (Multibank Dynamic Random-Access Memory) Memory technology developed by MoSys Inc. that uses 32 KB banks of DRAM, each having its own input/output port feeding a common internal bus. The technology allows for faster reading and writing of data.

Media - Networking wiring such as 10BASE-T and 100BASE-T UTP cable, and coax cable. The magnetic material deposited or coated on an aluminium substrate that is very flat and in the shape of a disk. The media is over-coated with a lubricant to prevent damage to the heads or media during head take off and landing. The media is where the data is stored inside the disk in the form of magnetic flux or polarity changes.

Megabit - Approximately one million bits, or exactly 1 bit x 1,0242 (1,048,576) bits. One million bits of data. (10 Megabits per second, or Mbps, means that 10 million bits of data are being transmitted over the network per second.) Don't confuse with megabyte, the usual measure of computer memory and storage space. Eight bits make up one byte.

Megabyte - A measure of computer memory equal to 1,048,576 bytes, each of which in turn is equal to eight bits, which is the smallest unit of data in the digital system and is symbolised by the number 1 or the number 0. A unit of data storage equal to approximately one thousand kilobytes, or one million bytes. As with other units of mass data storage, the precise size of a megabyte is expressed by a number that most of us wouldn't find it worthwhile to remember (1,048,576 bytes to be exact).

Megahertz - (MHz) A measurement of frequency in millions of cycles per second.

Memory - A computer's random-access memory. Memory temporarily holds data and instructions for the CPU. Defined as the internal storage areas of the computer. The most common forms are ROM (Read Only Memory) and RAM (Random Access Memory). This is where the computer stores information as it is working on it. It is temporary storage usually in the form of RAM chips. The computer only works on information in its memory. When it is done, it can be stored to disk.

Memory Bank - A logical unit of memory in a computer, the size of which the CPU determines. For example, a 32-bit CPU requires memory banks that provide 32 bits of information at a time. A bank can consist of one or more memory modules.

Memory Bus - The bus that runs from the CPU to the memory expansion slots.

Memory Controller Hub - (MCH) The interface between the processor, Accelerated Graphics Port, and RDRAM on motherboards that use Intel's 820 or 840 chipsets.

Memory Resident Program - These are the kind of programs that "hide" in memory and work only when you call on them. Hitting ALT-C sometimes can cause a "POPUP" calculator to appear on the screen, right on top of the program you were already running.

Memory Translator Hub - (MTH) The interface that allows SDRAM memory to be supported on a Direct Rambus Channel for motherboards using Intel's 820 chipset.

Menu - A list of available options that is used to complete actions in a graphical user interface. By clicking on one's desired selection from a predetermined list, a user is able to operate a program without learning a specific set of commands and their syntax. Some computer users prefer to maximise their efficiency by memorising the available commands anyway (for many of these more-advanced users, the term "menu" tends to refer to flyer from the local pizzeria that they hang up next to their monitors).

Merge - To combine information from one file with information of another file in a manner that maintains the inherent order (often alphabetical or numerical) of each.

Meta - A prefix used in computer science meaning "relating to" or "based on." For example, a metadirectory would be a directory relating to, or about directories. More simply put, a directory of directories.

Meta Tag - HTML information describing a Web page or document. In addition to information about the enterprise that created the page, important keywords are written as meta tags, which are designed to be found when a search engine seeks these words entered by a user. The clever use of meta tags used to associate keywords to a Website can significantly increase traffic to the site. To take a look at HTML code and meta tags while online, click on "View" in the menu bar in Microsoft Explorer, then select "Source" and click again.

MHz - Abbreviation for megahertz. One MHz represents one million cycles per second. The speed of microprocessors, called the clock speed, is measured in megahertz. For example, a microprocessor that runs at 200 MHz executes 200 million cycles per second. Each computer instruction requires a fixed number of cycles, so the clock speed determines how many instructions per second the microprocessor can execute. To a large degree, this controls how powerful the microprocessor is. Another chief factor in determining a microprocessor's power is its data width (that is, how many bits it can manipulate at one time). Typically used in this context to describe the speed of a computer's CPU, as in "K6-2/300 MHz." MHz only measures internal clock speed, not application performance. Many factors affect application performance. Speeds greater than 1000 MHz are usually referred to as GHz (Gigahertz).

Micro - A common term in computing meaning: 1. a microprocessor. 2. a computer. 3. something extremely small.

Micro BGA - (µBGA) Tessera, Inc. BGA chip packaging technique allows for a reduction in die package size, improved heat dissipation, and greater module densities.

Microcomputer - A computer in which the central processing unit (CPU) is the microprocessor. Home computers are microcomputers and are generally used by one person at a time.

Microprocessor - The integrated circuit chip that performs the bulk of data processing and controls the operation of all of the parts of the system. A disk drive also contains a microprocessor to handle all of the internal functions of the drive and to support the embedded controller. This is the computer system's main "brain" or control centre. This is where all of the calculations take place. Microprocessors are also called "processors" or "CPUs". This is what is given the number '286 or '386 etc.

Microsecond(s) - One millionth of a second (.000001 sec.).

Microsoft - Microsoft is the by far the largest software company in the world. Microsoft is run by Bill Gates, the world's richest man. Yet somehow, through it all, they manage to find the time to take care of the little things, such as squashing out their competition like cigar butts.

MIDI/.MID - MIDI stands for Musical Instrument Digital Interface, and is a standard method for computers and musical instruments to talk to each other. MIDI files are very compact ways of storing music. Rather than storing recordings of the music, they are like those paper rolls found on player pianos. They describe which notes to play when and on which digital instruments. MIDI files end with the characters .mid or .MID. There are sites all over the Internet where you can find free MIDI files. You can add background MIDI music to your home page by editing it with our home page tools.

Millisecond - (ms) One thousandth of a second (.001 sec.).

MIME - (Multipurpose Internet Mail Extension) An extension that lets you transmit non-text data (like graphics, audio, video) via e-mail.

Minimise - In Macintosh and Windows operating systems, as well as many software programs, a button found in the upper right hand corner of the screen (in most cases, but not always) that, when the user places the mouse cursor on it and clicks, it decreases the size of the current window so the window is no longer visible on the computer screen.

MIPS - (Million Instructions Per Second) a somewhat dated way of measuring the speed of a computer determined by how many instructions the machine can process per second.

Mirror - A replica Website set up to share the traffic on a busy site.

MIS - "Management of Information Services" MIS is the designation for the field of computer solutions internal to an organisation. An MIS department is typically responsible for administering the computer hardware, software, and networking within a company or group.

MMX - MMX technology is an enhancement to the Intel microprocessor that was introduced to make computers more capable of performing processor-intensive operations such as those common in the latest multimedia programs. The additions offered within MMX come in the form of a new set of instructions that are built directly into the processor hardware to allow for much faster computations of complex actions. If you thought "Space Invaders" was fun on your old computer, wait until you try it on a machine equipped with MMX. Multimedia extensions added to the Pentium instruction set, used by Intel, Cyrix and AMD processors to enhance video playback and graphics performance. All Pentium II, Pentium III and Celeron processors also include MMX capabilities. Intel claims that "MMX" is not an acronym, meaning "Multi-Media eXtensions" because they have filed for a trademark under this name. In reality, MMX instructions are intended to enhance programs that have multimedia capabilities.

Mode - The operational state of a piece of computer hardware or software. For example, if a Windows user thought she was about to experience a hard disk malfunction, (in many cases the computer would actually tell the user that hard disk failure was eminent) she would open Windows in the safety mode and be sure to backup all important files before having a technician examine the machine.

Modem - A communications product that sends computer transmission over a standard telephone line at pre-set speeds. MOdulator/DEModulator. A device that allows one computer to communicate with another by translating digital information from the computer into analogue data that can be transmitted by the phone lines.

Moderated Mailing List - A collection of email recipients who receive messages before they are sent to subscribers.

Module - An individual component of either computer hardware or a software program. In either case, modules are linked together in order to function.

Monitor - This is the computer's video display screen. It is the TV set looking part of the system. It however is only half of the video system of the computer. The other half is the graphics card that is plugged into the motherboard of the computer.

Monochrome - This is a kind of computer display that shows only two colours: black and white or green and white. Some black and white systems can display various shades of grey as well.

Moore's Law - A prediction made in 1965 by Gordon Moore, cofounder of Intel, stating the number of transistors occupying a square inch of integrated circuit material had doubled each year since the invention of the integrated circuit and that the multiplication of circuitry would continue. For the most part, the observation held true until the late 1970s when the time span of a year increased to about 18 months. Over time, Moore's Law has erroneously been associated with the notion that microprocessor speeds would double each year.

Motherboard - Also known as the logic board, main board, or computer board, the motherboard is the computer's main board and in most cases holds all CPU, memory, and I/O functions or has expansion slots for them. This is a vital part of your computer. It is the part to which all of the parts plug into. Some call it a mainboard.

Mouse - This device is used to move a pointer on your screen, which is a form of navigation. A mouse can be a big help when the operating system you use is based on a GUI (graphical user interface). A mouse is a small handheld pointing device that is used mostly in graphics programs to manipulate what is on the screen. The mouse has two parts: what you can feel and touch (usually having a body and two "buttons"); and the software which is the program that controls the mouse and allows your applications to access it.

MP3 - (MPEG Third Layer) A standard for the compression of audio files allowing for high compression ratios without a loss in sound quality. The compression of the audio signal can be likened to an encrypting of sorts. A special player is required to listen to MP3.

MPEG - A compressed video file format.

MSDOS - This is one of the official names of DOS ... MS-DOS or Microsoft DOS .... a version of DOS put out by the Microsoft Corporation.

MTA - "Mail Transfer Agent" Any server that is employed to delivery electronic mail. Another variation on this theme is the Mail Transfer "Secret" Agent, but if I told you any more about that, we'd have to kill you.

MTBF - Acronym for mean time between failure. Reliability rating indicating the expected failure rate of a product in power on hours (POH). Since manufacturers differ in the ways they determine the MTBF, comparisons of products should always take into account the MTBF calculation method.

MTTR - Acronym for mean time to repair. The average time it takes to repair a drive that has failed for some reason. This only takes into consideration the changing of the major subassemblies such as the circuit board or sealed housing. Component-level repair is not included in this number as this type of repair cannot be performed in the field.

MUD - "Multi-User Dungeon" In computerised role-playing games, a MUD is a game environment that allows multiple users to play at the same time without having to originate from the same place at the same time. Through the wonders of a MUD, college students from the west coast can be killed with swords by nerds from MIT without even leaving the dorms.

MultiCast - To broadcast an audio or video message over a network using special software such as Real Audio.

Multimedia - The use of a computer to display integrated text, graphics, animation and sound. As computers become more sophisticated and less expensive, the potential for use in multimedia presentations such as movies and interactive education increases.

Multiplex - No, this does not refer to a movie theatre with many screens. It is simply a fancy word for the process of taking a single communication channel and dividing it among several different signals.

Multitask - This refers to a computer's ability to perform different operations simultaneously, such as saving a file while applying a Photoshop filter. Like computers, some people have the skill of dividing their attentions between tasks. Others, like me, do not...excuse me while I chew my gum.