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STONE RIDGE, N.Y. 12484
INSTRUCTOR: Karl Wick SEMESTER: Spring 1999
The heart (but not brain) of a microcomputer is the motherboard. The motherboard holds all of the main components and lets them interact with each other. It also handles connections with the world outside of the case (such as the terminal and keyboard).
Some of the functional sections of the motherboard are;
Peripheral boards are circuit boards which plug into on the motherboard and perform some specific function or functions for or with it.
Memory is where information is stored temporarily and sometimes permanently within the system.
The Floppy Disk drive is a removable media device. We store information on a small removable piece of magnetized plastic. It is round and enclosed in a protective cover. The floppy disk holds a relatively small amount of data compared with other removable media devices. For most computer systems this amount is 1.44 kilobytes or appoximately 1500 characters of information. Some drives hold 720 kilobytes or 2.88 kilobytes. Early drives held less information.
Let us digress for a moment and review at the floppy disk (the media) itself:
Early floppy disks were enclosed in a soft plastic jacket and actually would 'flop' if you held them by the corner.
Today's floppy disks are encased in a hard plastic case and have a metal or plastic door which covers the opening through which data is read.
These modern floppies are less succeptible to damage then the older style but are still rather fragile as far as data retention is concerned. They are a magnetic medium and similar to audio and video tape and can lose data for any of these reasons:
The hard disk is a large capacity storage device. These drives are generally not removable, although some of the newer types do feature removable data cartridges. Hard disks have storage capacities of 10 megabytes to over eight gigabytes.
The CD ROM is a relatively new storage device which has become standard on almost all systems. The drive and media used for data storage are almost identical in apearance to audio CDs and players. The method of recording data differs because music publishers are sorely afraid of unauthorized "perfect" copies of their products becoming commonly available.
Many computer systems can read and play audio CDs through the use of software. Audio players cannot read or play computer CDs, however.
A CD ROM can hold about 650 megabytes of information, about the same as four hundred and fifty one floppy disks. The storage technology used is optical rather than magnetic. A series of pits in a surface is read by reflecting a laser beam off of the surface as the disk spins.
The power supply in a computer converts either AC line power or battery power to specific voltages and currents used by the computer. These voltages are pretty much standard throughout the industry.
Yes, it's self explainatory, but we should mention that a computer usually has a case to hold the other parts together and to protect them from damage. These cases come in three basic forms,
The passive protester of the electronics world. Holds back electrons. Changes electrical energy into heat.
Temporary storage for electricity. Like a bucket with a tiny hole. We can fill it, move it and use the water, but if we leave it overnight we will find it empty.
Like a theater usher, it keeps things moving.
Like a door which only opens one way. Lets electrons through in one direction only.
Switches and amplifiers. For computer circuits, used mostly as electronically controlled switches. A small signal can turn a large current on and off. sort of like a youngster moving a railroad switch with the aid of a pry bar. Can be controlled from somewhere else, like a door lock controlled from a central desk.
The base, substrate, or common ground. Gives components a place to sit. Also connects
them via traces which act like thin wires but are really a
part of the board itself.
In case you don't see two buttons above, click here to go to
chapter 3.