Working With Computers

A generation ago, the computer was an elite tool, available only to government, business and research/academic institutions. At the beginning of this century, the computer has become a common appliance in many homes and is an inescapable part of our daily lives.


Topics This Week

Being Digital - Binary Representation

Although the computer can execute a range of tasks, it can only process data in terms of mathematical calculations. Everything we do with a computer must be represented as some form of a number. Since, at its core, the computer is an electrical device, we must encode any data to be processed as a series of electrical states, the presence or absence of an electrical charge.

Binary Numbers: The numbering system used in machine language. All values can be represented by either the presence or absence of an electrical charge. (0 or 1)

What's important to understand is that since each binary digit will be represented by one bit, the more bits in a digital word, the greater the range of values that can be represented. This gives greater resolution to whatever is being digitized. For example: 16bit audio encodes sound with a range of 65,536 values; 8-bit audio encodes sound with a range of 256 values. As we will see later this semester, the greater resolution offered by 16-bits translates into higher quality sound.

The number of bits in a digital message will determine the range of values that can be expressed.

Data: All data in a computer is represented in as digital words made up of bits and bytes.


What's Inside - Computer Functions and Components

Hardware: The physical components of a computer system.

Although often thought of as a single device, a computer is actually a system of interconnected components performing a variety of simple functions in completing a task. As a system, any computer can be broken down into four basic functions.

Follow this link for a diagram of how these are functions are handled in your computer: Computer System Flow Chart.

Processing

The CPU (Central Processing Unit) is the chip which handles the main operations done in a computer. A computer is generally designed around a particular chip.

Memory

Several different types of memory are used in a computer. Issues to consider are the size of memory and the speed at which the memory is accessed.

Input Devices or Peripherals:

Output Devices or Peripherals:

Device Drivers

A driver is a piece of software code that identifies a specific device to the host operating system and allows communication between the device and the computer it's connected to. In the past, this often required that you installed software before connecting the device. In OSX, Apple has attempted to include drivers for many common devices in the operating system itself. We refer to devices that can be direcly connected to the Mac without the need for additional drivers as "class compliant." Many common peripheral devices, like printers, fall into this category, and using them with your computer should be as simple as just plugging them in. Your Oxygen 8 II keyboard is an example of such a device, and it should be ready to use as soon as it's connected. Although many consumer devices are class compliant, more specialized hardware peripherals, such as professional audio interfaces, like the Line 6 UX2, still require you to install driver software.


System Connections

Data is transferred from one part of the computer to another at different speeds. These rates are measured in different ways. The most important of these to understand is the speed of the data or system bus and the data rate for network and mass storage transfers. In the case of communications devices, this is called bandwidth, the amount of data that can be passed along a communications channel in a given period of time.

Common Transfer Rates
Data Rate Abbreviation Bits per Second
Bits per second bps actual value
Kilobits per second Kbps 1000 bits per second
Megabits per second Mbps 1,000,000 bits per second
Gigabits per second Gbps 1,000,000,000 bits per second

Transfer Protocols

Audio Visual Connections


Software

A set of instructions the allows the computer to function.

Computer Languages - Computers are programmed to respond to specific data input using any of a number of computer languages. Some current languages include: C, C++, and Java. Lower level functions, such as data entry and encoding are handled by protocols. As we saw earlier, ASCII (American Standard Code For Information Exchange) is a way of encoding data entry keystrokes as numbers. Next week we'll see that the MIDI protocol allows musicians to encode musical performance gestures as numbers.

Operating System - A set of instructions and conventions which allows various applications to run efficiently. Generally the user will have no direct contact with to OS other than configuring various aspects of it. In Mac OSX this is done in the System Preferences panel. Apple Menu>System Preferences.

Mac OSX - All Apple computers at the college are running Mac OSX. All of you are now using version 10.5, however version 10.6, named "Snow Leopard" will be out in Fall 2009. For more information on the technologies in the Mac OS, check out: http://www.apple.com/macosx.

Applications - Software that enables a computer to do specific tasks. Music software that we will use this semester includes:

Any piece of software will have specific requirements that need to be met to work properly. These are usually available in a manufacturer's promotional material.


Classroom Activity: Recording With Your Laptop.

Complete this short activity that will introduce you to the basics of recording with the built-in microphone in your MacBook Pro.


Review Questions


Some Things To Think About


Computer Vocabulary

In addition to the links for Wikipedia, computer vocabulary can be referenced through: The Free Online Dictionary of Computing.


Binary
Bits
Blu-Ray
Bytes
Computer Language
CD-ROM
CPU
Data Bus
Decimal
DVD
Firewire

Gigabyte
HD-DVD
Input Devices (touch screens, MIDI controllers, digitizing pad, etc)
Kilobyte
Megabyte
Memory (RAM, ROM)
Modem
Output devices (plotter, printer, etc)
Peripheral
Protocol
Storage (CD-ROM, hard disks, USB Flash Memory, DVD)
Terabyte
USB and USB2