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Chapter 4 

Hardware: The CPU & Storage
Microchips,
Miniaturization, & Mobility

Vacuum tubes
used in old radios, light bulb-size electronic tubes with glowing
filaments, the ENIAC (1946) used 18,000 of them, high failure rate,
damaged tubes had to be replaced
Transistor - a tiny electrically operated switch, or gate,
that can alternate between on and off many millions of times per
second, developed by Bell Labs in 1947
Integrated circuit
an entire electronic circuit formed on a single chip usually made
of silicon (semiconductor), solid state device where electrons travel
through solid-state material


Microchips store and process data in all the electronic gadgetry,
has millions of micro miniature electronic circuits, industrial rice, photolithogra</span><span
class="Heading-00202--Char" style=" font-size: 10pt; color: #000000;
">phy process


Processor speed +cache sizes + memory access
times affect computer performance.

How the Processor
or CPU Works

A processor, also called the Central Processing Unit (CPU) carries out the basic instructions that operate a computer.


The term mi</span><span class="Normal--Char" style=" font-weight: bold;
">croprocessor refers to a personal computer processor chip.
Processors
contain the Control
Unit (traffic cop) and ALU
(performs arithmetic and comparison operations).
Machine Cycle : Fetch, Decode, Execute, Store
Pipelining
Word size
The number of bits a processor may process at one time, typical values
of 32 and 64 bits, the larger the word size, the faster the processor
(everything else being equal).
Processor
also contains registers
(high-speed storage locations)
Buses
electrical data roadways through which bits are transmitted

Processing Speeds

and the system
clock.
Processors today are generally superscalar.
Speed measurement
units for various computer categories
Hertz one clock cycle
MHz, GHz: millions or billions of clock cycles per sec, for
microcomputers
MIPS: millions of instructions per sec, for workstations, mainframes


Flops: floating point operations per sec, for supercomputers

Microprocessors

.


Two kinds of microprocessors used in most personal computers today:


Intel-type chips made by Intel, AMD, and others, used by 90% of computers


Most high-performance desktop PCs use some type of Pentium processor.  Many notebook computers and Tablet
PCs use a Pentium M processor.  Less expensive, basic PCs use Celeron.  The Xeon and Itanium are u</span><span class="Heading-00202--Char" style=" font-size: 10pt;
color: #000000;">sed for workstations and low-end servers.


Motorola-type chips are made by Motorola for Apple Macintosh computers.  Today</span><span class="Heading-00202--Char" style=" font-size: 10pt;
color: #000000;"></span><span class="Heading-00202--Char" style=" font-size: 10pt;
color: #000000;">s Apples are using Intel processors.


Hyperthreading allows the processor to mimic the power of two
processors.
Dual-core and multi-core processors are now being offered. This is two or
more processors on a chip.
System on a chip integrates the functions of a processor, memory
and video card on a chip. 
Parallel processing is a method that uses multiple processors
to accomplish a task. (D</span><span class="Normal--Char" style=" font-weight: bold;">ual
Processors, Multi-processors)
Chipset
collection of interconnected chips that determine what types of processors,
memory, and video card ports, and other hardware will work on the same
motherboard


Analog vs. Digital.


Machine language - a binary-type programming language built into the CPU that the computer
can run directly, every higher level language must be translated to
machine language before it can be run by the processor (binary code
vs. source code).


Binary system, bit, byte
ASCII, EBCDIC, Unic</span><span class="Normal--Char" style=" font-weight: bold;
">ode representations.
Parity bit
an extra bit attached at the end of a byte to check data accuracy, even
and odd, 1-dimensional vs. 2-dimesional

How Memory
Works

Memory stores: (1) Operating System (2) Application Programs (3) Data


Types of memory chips:


RAM (Random Access Memory) to temporarily store program instructions and data, volatile, various types: DRAM, SDRAM, DDR-SDRAM, etc.

RAM Configurations 512 MB (generally, range today is between
256 MB and 16 GB)

How Cache Works:
Level 1 (Internal) & Level 2 (External or Internal)

Cache - temporary storage for instructions and data that
the processor is likely to use frequently, thus speeding up processing


Level 1 (L1) cache part of the processor chip, 32KB, 64KB