When a new desktop user sets up their system fresh from the store, they often refer to the big main box as the desktop, or sometimes the tower. Most don’t reckon that this box contains the motherboard, the heart of any PC, or perhaps the brain would be a better description.

The motherboard is also known as the system board, the main board, or the logic board. Commonly abbreviated as MoBo, the motherboard contains the central processing unit, or CPU, a microchip that is truly the brain of the PC. This CPU is part of a circuit board located on the motherboard, with also contains the main memory of the desktop. This main memory is called RAM, or random access memory. Many people just refer to RAM as “memory” but this can be misleading because the motherboard of the desktop will contain other types of memory as well. For instance, the video display card attached to the motherboard will have memory of its own, as will the sound card. As their names imply, the video card processes video images and the sound card processes audio. Both are vital motherboard components.

The motherboard will be connected to other parts of the desktop system via ribbon cables and other connection devices. These parts include external data storage and retrieval such as the hard drive, the CD ROM (or CD reader writer), the DVD unit (which may be a player or a player writer), the floppy drive, though less common these days, and even connectors to tape backup systems.

The motherboard also connects through ports and cables to such devices as scanners and printers. Many units these days are combination printer fax and scanner in one package. They usually connect to the motherboard via a USB cable.

The most common peripherals, or outside connecting units, that the motherboard is attached to are the keyboard, monitor, and mouse. These are the parts that the user uses to see the program he or she is working with and to manipulate it and input data. In fact it has been said that the fastest upgrade that can be made to a motherboard as far as inputting information is simply in teaching the user to touch type, rather than hunt and peck.

Most people want to connect to the Internet. This is also accomplished by connecting to the motherboard. It is done by connecting a dial up modem to the motherboard directly or by using external cables to connect with a cable modem or DSL modem if high speed internet access is needed. Some users attach a network card to the motherboard and connect directly to a T1 for the ultimate in high speed Internet use.

Motherboards vary in size and construction. Many lower end desktop models try for compact size and connect all of the common cards usually attached to the motherboard in a space saving way by building them directly onto the motherboard. Some laptop or notebook computers do this as well. With a notebook desktop a smaller motherboard is essential to keep size where it should be.

Since the computer revolution of the early 1980’s, motherboards have become smaller and smaller in size. The first computer built by Bill Gates, founder of Microsoft, was an Altair, a kit desktop that was enormous in size compared to today’s PC’s. Early home and small business computers were not compatible with each other. Most small business computers used CP/M as an operating system, which stood for control program microcomputer. Today’s users would hardly call them micros because they were larger than what we are used to now, but compared to the mainframes of the day they were micro. All of these CP/M computers from different manufacturers have different styles and sizes of motherboards. Then home computers from companies like Apple, Commodore, Radio Shack, Texas Instruments, Timex and Atari came into the picture, all with good products for their design, but totally lacking in compatibility with each other and the rest of the world. There was no way in the world an Apple motherboard would fit into a Timex case or run for a Radio Shack or TI desktop. Compatibility and the current desktop, most using a Microsoft operating system called Windows, with similar motherboards, changed all that.