Chapter 2 : Understanding the Parts (selected notes)

Some background

• computer as machine that manipulates data according to a set of instructions
• stored program concept and von Neumann design: processor, storage, input, output
• generations: vacuum tube, transistor, integrated circuit
• categories of computers: supercomputers, PCs, PDA, embedded
• binary number system: bits and bytes
• Highlights magazine 1965 article on counting in binary on your fingers; 0 to 31 on one hand!
• Everything is stored in the computer as 0's and 1's! programs, sounds, images, documents, etc.
• kilo, mega, giga, tera

Input and Output devices

• some I/O devices are integrated into system unit
• selected input devices
• keyboard input: QWERTY, Dvorak
• keyboards produce text characters, represented in binary using ASCII or Unicode encodings
• mouse input: wired/wireless, 1-button, 2-button, 3-button, invented in 1968!
• digital camera: pixels, CCDs, compression using JPEG, storing images and colors
• microphone input: storing sound, compression using MP3
• The University of Tennessee has developed some Flash modules that explain how numbers, text, and images & sound are digitized and stored
• selected output devices
• monitor output: CRT, LCD, LED, pixels, RGB, additive colors
• printer output: laser, inkjet, CMY, subtractive colors
• sound output: D/A
• We will revisit some of these in Chapter 6

The System Unit

• Ports to connect I/O devices: USB (general purpose), Ethernet (network), audio in/out, VGA or DVI (monitor)
• Motherboard, a circuit board upon which ports and internal component are mounted and interconnect via bus lines
• Central Processing Unit (CPU), the processor
• Random Access Memory (RAM), very fast but volatile main memory unit
• Expansion slots and cards, that allow you to attach additional ports to the motherboard
• Drive bays, where storage devices are mounted: hard drives (magnetic), CD and DVD (optical), all are non-volatile
• Power supply, converts electrical current from outlet to a form usable by the various components
• We will revisit some of these in Chapter 6

Ergonomics

• Setting up your computing equipment to prevent injury and discomfort
• what are some health concerns related to computer usage? see page 83
• Nicely illustrated by Figure 37 on page 81
• chair with lumbar (lower back) support, adjustable height and angle
• top of monitor at about eye level or just below, and about an arms length away
• keyboard and mouse at height such that forearms are level and wrists are straight, use of wrist rest
• Search images.google.com for "ergonomic keyboard" and be amazed at the results!
• how do laptops present challenges to achieving the ideal monitor and keyboard positions?
• Not just set-up, but also practices like remembering to blink and taking periodic breaks