COSC 101B

The torture will stop when moral improves

Review

Binary code is the basic computer language

Based on circuit being open or closed Open circuit: No electricity passes=0 Closed Circuit: Electricity passes=1 This represents 1 bit of information▪ A bit has only two states to choose from▪ True or False▪ Yes or No▪ 1 or 0

Add up the Bytes to make a meal

Bits are then organized into groups 4 bits = 1 Nibble 8 bits = 1 Byte 1024 Bytes = 1 Kilobyte 1024 Kb = 1 Megabyte 1024Mb = 1 Gigabyte 1024 Gb = 1 Terabyte

Time keeps ticking by . . .

Processor speed based on hertz System clock is a quartz crystal through

which electricity passes:

The crystal vibrates at a set frequency, called Hz

Processing happens on every vibration Current Olin 212 lab machines process

every 2.83 billionths of a second

Let the races begin . . .

System Speed is determined by four factors: Processor speed Speed and amount of RAM (Random

Access Memory) Amount of Cache, measured in Bits not

Bytes Front Bus Speed

RAM: Not a mean animal

Types of RAM Physical RAM▪ Volatile▪ Located on Mother board and can usually be upgrade

Virtual RAM▪ Temporary usage of available Hard Drive space

Cache▪ Volatile▪ Located on processor and not normally upgradable

Flash▪ Only non volatile RAM▪ Flash cards for cameras and USB drives are examples

ROM: Not a Ferengie (None of you

got that, right?)

ROM Read Only Memory Preloaded from factory Holds OEM specs on computer hardware Holds basic Operating System that runs

start up and looks for loaded Operating System

CMOS: Not an Alien Monkey

Complimentary Metallic Oxide Semiconductor (CMOS is fine for tests) Holds Date and Time Holds basic system set up information POST: Power On Self Test Volatile▪ Requires a lithium battery for power

Hardware, but not from Lowes

Anything you can touch Four basic categories

Processing▪ CPU, RAM, ROM, CMOS, Motherboard

Storage▪ Storage devices, both internal and external▪ Removable Storage devices such as DVD’s and USB

drives Input▪ Keyboard, Mouse, microphone, scanner, etc

Output▪ Monitor, printer, etc

The output basics . . .

Monitors Resolution measured in pixels per inch

(PPI) Two main types▪ CRT – Cathode Ray Tube (looks like old TV)▪ LCD – Liquid Crystal Display (flat panel)

Other types▪ LED (newest technology)▪ Projector▪ Plasma – (don’t let it burn in!)

Other output basics

Printers Resolution measured in DPI (dots per inch) Several consumer grade printers▪ Dot Matrix (low quality, low cost)▪ Ink Jet (medium quality, expensive ink)▪ Laser (high quality, expensive and expensive

toner) Commercial grade▪ Thermal (very high quality, very expensive)▪ Plotter (low quality, mainly used for architectural

plans)

In and Out basics

Modems Modulator/Demodulator Used for connecting computers to external

networks, like ISP’s Formerly used on telephone lines, now DSL and

Cable▪ Max telephone speed 53Kbs by Federal Law▪ DSL 256Kbs, Cable up to 1.5Mbs

Touch Screens▪ Common in ATM’s and self check out devices▪ Popular with personal devices (cell phones and

tablets)

Scanners

Input devices Several types

Flatbed scanners Handheld scanners Barcode readers OMR-Optical Mark Reader▪ Used to grade standardized tests

OCR – Optical Character Reader▪ Used with text to speech software

Moving on to the new . . .

Secondary storage devices Represent “permanent” storage – Non

Volatile!▪ All devices can fail, some less likely than

others Most are moveable▪ External or removable media (more later)

Some are not so moveable▪ Internal hard drive (have to open computer to

get it)

Secondary Storage: Part Two

Divided into two basic categories Magnetic▪ Information stored as a charge▪ Negative charge = No or 0▪ Positive charge = Yes or 1

Optical▪ Physical surface of disc broken into pits and

lans▪ Lan = No or 0▪ Pit = Yes or 1

Magnetic Storage

Magnetic: Hard drives▪ Internal drives▪ External Drives▪ Hard Disc Stacks

Digital Tape▪ Usually used in Enterprise environments for

back up storage USB drive▪ Inexpensive way to back up data and have

extreme portability

Magnetic Types Part Two

Internal Hard Drives Size currently available is well into Terabyte

range Are susceptible to Head crash▪ What happens when Read/Write head makes

contact with disc▪ Can be caused by:▪ A fingerprint▪ A smoke particle▪ A human hair

Available in Solid State format (no moving parts) which are not susceptible to Head Crash

Magnetic Types Part Three

External Hard Drive Available up to several Terabytes Normally connected via USB (newest

connections USB2) Inexpensive and easy to use Still susceptible to Head Crash

Magnetic Types Briefly . . .

Floppy Drives 3.5 inches, up to 1.44 Mb storage Rarely used

Zip Drives Up to 250 Mb storage Rarely used

Digital Tape Up to 800 Gb Storage Primarily used for commercial backup

Magnetic types briefer still . . .

USB Up to several Gb of storage (in excess of

20Gb now available) Very convenient Less likely to fail Unfortunately easy to misplace.

Hard Disc Stack Purely commercial Moveable large storage (several

Terabytes)

Optical Storage

CD Up to 720 Mb of Storage CD ROM▪ Read Only Memory▪ Many programs come on CD ROM

CDR▪ Recordable, but only once

CD RW▪ Recordable, many times

Optical Storage, The Sequel DVD

Up to 17 Gb Storage DVD ROM▪ Read Only Memory▪ Movies also come in this format

DVD R▪ Recordable, but only once

DVD RW +/-▪ Recordable, many times

Blue Ray▪ Up to 60 Gb of Storage, primarily video media currently

What’s Next?

Holographic Data storage Uses multiple lasers to read multiple

angles Up to 2 Tb of storage

Protein Coated Disc Uses light sensitive genetically

engineered microbes to store data Up to 50 Tb of storage

Adding Soft to the system

Software basics All of the instructions that run the

computer All of the programs you use Must be written in computer language Nothing that you can touch

Two main categories System Software Application Software

All Systems GO!

System Software Required to run system Little input required from user Three subcategories▪ Operating Systems▪ Utilities▪ Drivers

Operating Systems

2 basic categories Text base▪ DOS (Disk Operating System)▪ First OS for PC’ss▪ Still works on current machines

▪ Linux Graphical User Interface (GUI)▪ Windows▪ Mac OS

Operating Systems

OS Functions Provide a user interface▪ A way to interact with the machine

Manage resources▪ Control how much RAM is being used by

which programs as an example Run Programs

Utilities: not your average bill

Utilities Used to maintain system or improve

performance▪ Anti Virus▪ Anti Spyware▪ Anti Adware▪ Disc Cleanup▪ Disc Defragmentor

Let’s be careful out there

Malware: why you need certain utilities Viruses▪ Normally delivered through email as an

attachment▪ Do not open attachments unless you are sure

what they are Trojans▪ Programs that pretend to be good, but are bad▪ Example: Waterfall.scr was supposed to be a free

screensaver of a waterfall, but contained malware that deleted files and allowed remote connection

Worms▪ Enter through security holes in the OS

Spyware is not James Bond’s suit

Spyware Loaded without user knowledge Can be gotten from any website Simply hitches on to the web site

download and snuggles into your computer

Can cause it to run slowly or keep some programs from running at all

Can also relay information back to programmer

Adware: they are looking for you

Adware Downloaded from visited site without

user knowledge Can cause unintended Pop Ups Can hijack your browser to force you to

certain sites Can return information from your

computer to the programmer Can cause the system to run slowly

Drivers: not all of them are bad

Drivers Software for hardware Every piece of hardware requires a

driver Instructs the OS on how to use the

hardware

Other Utilities

Disc Cleanup Removes temporary files taking up

unnecessary space Disc Defragmenter

Puts relevant data in the same sectors on the Hard drive

End of today’s fascinating Foray

Test on Thursday.

There will be no mercy

See you then