PC Hardware

Technical Terms Beginning With M

mailing list

A list of subscribers to a particular discussion group. This database can be used to distribute eZines (electronic magazines).


A link to an e-mail address. When a visitor clicks on this line of text (or graphic), the Web browser's e-mail program automatically opens and allows the visitor to send an e-mail message directly to the recipient.


See motherboard


A type of Web site that allows merchants to set up "shops," the virtual equivalent of a traditional shopping mall. A Web site located in a mall benefits from the traffic generated by every other member of the mall.

MDA (Monochrome Display Adapter)

Displays text only at a resolution of 720 pixels by 350 pixels. An MDA is perfect for use with MS-DOS-based word-processing and spreadsheet programs. The MDA uses a 9-pin male connector.

megabyte (MB)

An amount of computer memory equal to 220. 1,048,576 bytes = 1024 kilobytes. One megabyte can store more than one million characters.

megahertz (MHz)

One million hertz (one million cycles per second). A measurement of clock speed.


The area within a computer where information is stored while being worked on. It stores information (in the form of data bits) that the CPU and software need to keep running.

Micro Channel Architecture (MCA)

A short-lived 32-bit expansion bus that was a proprietary design of IBM used on the IBM PS/2 computer. By abandoning the open design of the existing PC market, IBM limited the willingness of developers and buyers alike to use MCA.


Just like the microphone on a tape recorder. Allows input of voice or music to be recorded and saved to a computer file.


An integrated circuit containing the entire CPU of a computer, all on one chip, so that only the memory and input/output devices need to be added.

MIME (Multipurpose Internet Mail Extensions)

A new Internet standard for moving around sound and pictures by email.

mini connector

A type of power supply connector primarily used on 3.5-inch floppy disk drives.

mirror site

An Internet site that contains exactly the same information as another site elsewhere in the world. These are created to respond to heavy traffic and spread the load on popular sites.

modem (MOdulator/DEModulator)

Converts computer data to information that can be transmitted via wires (telephone, ISDN, fiber optics, as well as wireless communication). Allows communication between computers over long and short distances.


A person who ensures that all contributions to a newsgroup are suitable before allowing them to be posted publicly.

Molex connector

Type of power supply connector primarily used for devices that need both 12-volt and 5-volt power (floppy disk drives). The most common type of connector.


The primary output device that resembles a television set-it visually displays text and graphics.


Also known as a PWB or printed wiring board. The large circuit board found inside the computer. For all practical purposes, it is the computer. It contains the following items: chip set, data bus, address bus, expansion slots, clock, battery, and memory.


Device used with graphical environments to point and select objects on the system's monitor. They come in a variety of shapes and sizes.

MTBF (mean time between failures)

A standard means by which vendors estimate the expected lifespan of a given product line.


The operation of more than one application at what appears to be the same time on the same PC. The CPU quickly switches between the various programs, making it possible to work in more than one program at once.