Since the early 1970s, microchips have gotten smaller & smaller yet more & more powerful & faster
The evolution of small electronic components has been relatively quick
Tubes - Transistors
Miniaturization Miracles: Microchips &
Microprocessors
Different kinds of Microchips
-Microprocessor
-memory
-Logic communications
-graphics
-math coprocessor chips
The microprocessor has presented us with gifts that we may only
barely appreciate - portability & mobility
The Binary System: Using on/off electrical states to represent
data & instructions
-uses two numbers: 0 & 1
ex. letter “G” - 01000111
Measuring Capacity :
How many representations of 0s & 1s can be held in a computer
or a storage device?
Bit: each 0 or 1 which is short for “binary digit”
Byte: to represent letters, numbers, or special char, bits are
combined into groups
A group of 8 bits is called a byte - represents one
character, digit, or other value
How many representations of 0s & 1s can be held in a computer
or a storage device?
Kilobyte: (K, KB) is about 1,000 bytes
-a common unit of measure for memory (primary or
secondary storage for older computers
-is about one-half page of text
Gigabyte: (G, GB) is about 1 billion bytes formerly measures mainframe computers typical secondary storage capacity (hard-disk) & main memory (RAM) of today’s microcomputers
-is about 500,000 pages of text
Exabyte: (EB) is about 1 quintillion bytes
-estimated that all the printed material
Binary Coding Schemes :
ASCII - (American Standard Code for Information Interchange) - most widely used on microcomputers
Machine Language :
Machine code - is the computer’s “native language”
- is a binary-type programming language built
into the CPU that the computer can run directly
CPU - works with other circuits such as main memory to carry out
processing
follows the instructions of the software (program) to manipulate data into information
consists of two parts: (1) the control unit, (2) the arithmetic logic
unit (ALU)
The Control Unit
for directing signals
deciphers each instruction stored in the CPU and then carries out the instruction
ALU ( Arithmetic/ Logic Unit )
for arithmetic & logical operations
performs arithmetic operations and logical operations and controls the speed of those operations
volatile - the contents are lost when the power goes off or
turned off
Secondary storage hardware, devices that permanently hold data
and information as well as programs
Hard disks, Optical disks, Magnetic tape, Smart cards, Flash
storage, Online Storage
Secondary storage is all data storage that is not currently in acomputer’s primary storage (main memory, or RAM)
RAM (Random Access Memory) temporarily holds (1) softwareinstructions & (2) data before & after it is processed by the CPU
ROM (Read-Only Memory)
cannot be written on or erased by the computer user without special equipment contains fixed start-up instructions
contains fixed up start-up instructions
arithmetic operations - fundamental math operations: addition, subtraction, multiplication, division, equal to, greater than, less than or equal to, not equal to
Four basic operation known as the machine cycle:fetches an instruction decodes the instruction executes the instruction
language translators - rapidly convert the instructions into machine language
Unicode - 1990s - uses 2 bytes (16 bits) for each character; rather than 1 byte (8 bits)
EBCDIC - (Extended Binary Coded Decimal Interchange Code) - 1963-1964-used with large IBM & IBM-compatible computers, such as mainframes
Terabyte: (T, TB) is about 1 trillion bytes-high-capacity disk storage is expressed in terabytes1
-is about 500,000,000 pages of text
Petabyte: (P, PB) is about 1 quadrillion bytes
-huge storage capacities of modern databases are now expressed in petabytes
Megabyte: (M, MB) is about 1 million bytes
-measures of some microcomputer memory capacity today
“microscopic processor” or “processor on a chip” - is the miniaturized circuitry of a computer processor modified microprocessor used in machines are called microcontrollers, or embedded computers
The system unit is the main part of a computer system
Optical Disks: CDs & DVDs - has become the favorite medium
for music, movies, even softwares
CD-ROM - read only
650 Mb
CD-R - recording only
can be written once but can be read many times
Optical Disks: CDs & DVDs - has become the favorite medium
for music, movies, even softwares
DVD-ROM
-versatile video disk
-high capacity
-can store 4.7-18 gb
DVD-R - recordable DVDs
Blu Ray - to enable recording, rewriting, & playback of HD
videos, as well as storing large amounts of data
-25 - 50 gb
-use blue-violet laser for a more focus
Smart cards
-a card with an IC - a microprocessor & memory chips into it
-contain OS, can store & process, interactive
Optical Memory Cards
-laser recordable, card used with optical reader
-can be written once can never be erased
-highly secure, counterfeit-resistant features
Flash & Solid State Memory - become the most important forms
of mobile secondary storage
-unlike DVDs with moving parts that can break, it is in a “solid state” - computer memory chips
-non-volatile (retains data even power-off)
drawback (memory circuits wear out after repeated use)