Transcript Computers and How They Work

Computers: How They Work
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What is a Computer
Components of Computer
World’s First Computers and CPUs
Mother Board
Machine Code and the processor’s Instruction Set – Software
Memory types (ROM, DRAM, SRAM, FLASH)
Hard Drive
Compact Disk
Keyboard
Monitor
The Mouse
Other I/O
DSL and connection to Internet
File Compression
Demonstrations
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PC Mother Boards
Memory
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Hard Drive
Magnetic Tape
Punch Cards
CDs
SIMM cards
Polarized Films
LCDs
Keyboard
CCD chips
What is a Computer?
A machine that stores
instructions and data and
operates on
information/data.
http://www.sscnet.ucla.edu
Jacquards Loom
Circa 1804
Charles Babbage’s first attempt at
a Computer
The Analytical Engine, c. 1822
► Designed
to use Jacquard
punch cards to store and run
a program
► Mathematician,
Augusta Ada Lovelace,
created programs
► Steam Powered
► 25,000 parts
► 15 tons and 8 feet high
► Never completed
http://concise.britannica.com
Difference Engine II
► Designed
to
calculate
polynomials and
compute trig
and log
functions
► C. 1847
► Crank operated
http://www.computerhistory.org/babbage/
Microprocessor
►A
logic machine that
can execute a a small
set of instructions.
► A Central Processing
Unit (CPU) integrated
into a single chip
(i.e. constructed as an
integrated circuit on a
single piece of Silicon)
http://en.wikipedia.org/wiki/Central_processing_unit
Components of a Computer
► Processor
► Memory
► Input/Output
Processor
Memory
(ROM, RAM,
Registers, Cache)
Output
(Monitor, speakers,
USB Drive, Printer,
DSL, Hard Drive)
USB – Universal Serial Bus
Input
(Keyboard, Mouse
USB Drive, DSL,
Touchscreen, Microphone,
Hard Drive)
DSL – Digital Subscriber Line
What’s Inside a basic CPU?
(Central Processing Unit)
► ALU
(Arithmetic Logic Unit)
 Performs addition, division, etc.
► Instruction Decoder
► Program Counter
► Instruction Register – stores current
instruction being worked on.
► Data Registers – stores current data being
worked with.
► Accumulator (place for storing a sum)
► Clock for sequencing operations
Memory – A Device that
“remembers” a previous input.
Registers are the high speed memory on
the CPU chip. These registers are used
for storing data that is frequently needed.
Instructions are pre-fetched and stored in
registers too so that they are ready when
needed.
4004 Intel Processor
Registers
1-bit Latch (Flip Flop)
Static RAM and registers are constructed with this logic.
The state of Q is retained as long as power is on.
Static RAM –Non-volatile Random Access Memory
4-word Static RAM
Memory Hierarchy
http://www.surriel.com/lectures/hierarchy.gif
Cache Memory
http://content.answers.com
SRAM
► Static
Random Access Memory
► Retains data in memory as long as power is on
► Uses flip flops (8 transistors each)
► Fast but more expensive due to more chip realestate needed for each memory location compared
to DRAM
► Used for cache memory
► Fast Access time  10 nanoseconds
DRAM and SDRAM
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Dynamic RAM
 Dynamic refers to the need to
refresh the data
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Synchronous DRAM
 (Timing of memory chip is
synchronized with CPU clock)
Data is stored as electrical
charge in capacitors
► Capacitors will discharge
requiring that memory be
refreshed every few
milliseconds.
► Dense therefore least
expensive form of memory
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http://www.electronics.dit.ie/staff/tscarff/memory/ram.htm
The word “random” means bytes can be accessed randomly.
Data access is not sequential like a magnetic tape.
http://www.cse.scu.edu
SIMM & DIMM
► Single
In-line
memory module
► Dual In-line
memory module
► These cards are
DRAMS
http://en.wikipedia.org/wiki/DIMM
ROM of three memory locations, each “word” of
Diodes
memory is 3 bits
► Read Only Memory
► Data contents can not
be changed
► Data retained even
when power is off
► Manufactured with the
data
► Used for booting up
computer and loading
Operating System
► Device Driver software
http://www.compeng.dit.ie
Flash Memory
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(Electrically Eraseable
Programmable Memory)
Using Floating Gate
Transistors to store bits
Non-volatile (power not
needed to maintain
data)
MP3 Players are flash
drives with extra
circuitry to decode data
to analog music signals
Cellular Phones
Digital Cameras
Very resistant to
temperature, shock,
field stress
http://electronicdesign.com/Articles/ArticleID/16383/16383.html
Hard Drive
120-240 GBytes
► Data
http://www.metallurgy.utah.edu/
stored magnetically
► Permanent Storage, Non-volatile memory
► Fast - Spins 4,500 to 12,000 rpm
► Dense and Inexpensive
► Data easily erased and rewritten
► Iron Oxide or very thin magnetic film applied with
a sputtering process stores magnetic data
► Not random access
Actuator
Actuator Arm
Platter
Spindle
Read/Write head
Multiple Platters
Head 20-50 nm from platter surface
A human hair is 100 nm
Read-Write Head
How Stuff Works
wikipedia
www.hddtech.co.uk
The voice-coil actuator controls the movement
of the actuator arm
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Positions the
read/write heads
Similar to a speaker!
Uses a coil and
permanent magnet
Converts electrical
signals into mechanical
movement
In this picture, magnet
has been moved to the
left during disassembly
to expose the coil
Coil moves freely
under the magnet
http://www.storagereview.com/guide2000/ref/hdd/op/over.html
Small Tolerances
5-80 Mbytes/sec media transfer rate
As an analogy, a magnetic head slider flying over a
disk surface with a flying height of 25 nm with a
relative speed of 20 meters/second is equivalent to
an aircraft flying at a physical spacing of 0.2 µm at
900 kilometers/hour. This is what a disk drive
experiences during its operation.
”
—Magnetic Storage Systems Beyond 2000, George C. Hadjipanayis
Software commands Hardware
C++ high level codes gets
compiled/translated into low level
machine codes
while (amt2 <= amt1)
{
amt1 = amt1 + 100;
amt2 = amt2 + 0.05*amt2;
year++;
}
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while (amt2 <= amt1)
004015BB fld
dword ptr [ebp-8]
004015BE fcomp
dword ptr [ebp-4]
004015C1 fnstsw
ax
004015C3 test
ah,41h
004015C6 je
main+70h (004015f0)
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{
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amt1 = amt1 + 100;
004015C8 fld
dword ptr [ebp-4]
004015CB fadd
dword ptr
[__real@4@4005c800000000000000 (0046f0a4)]
004015D1 fstp
dword ptr [ebp-4]
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amt2 = amt2 + 0.05*amt2;
004015D4 fld
dword ptr [ebp-8]
004015D7 fld
dword ptr [ebp-8]
004015DA fmul
qword ptr
[__real@8@3ffaccccccccccccd000 (0046f098)]
004015E0 faddp
st(1),st
004015E2 fstp
dword ptr [ebp-8]
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year++;
004015E5 mov
eax,dword ptr [ebp-14h]
004015E8 add
eax,1
004015EB mov
dword ptr [ebp-14h],eax
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}
Fetch-Decode-Execute Cycle
► Fetch
an Instruction:
 Fetch instruction at address stored in address
register
 Increment Program Counter
 Load the Instruction Register with this
Instruction
► Decode
 Decode the Instruction
 Fetch the operands
► Execute
 ALU or other logic performs the operation
 The result is then written to memory or to a
register.
A Computer is much more than a processor
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Processor Intel® Core™2
Q6600 Quad-Core (8MB L2
cache,2.4GHz,1066FSB)
Video Cards 768MB nVidia
GeForce 8800 GTX
Memory 2GB* Dual Channel
DDR2 SDRAM at 667MHz - 2
DIMMs
Hard Drive: 500GB* 7200RPM, SATA 3.0Gb/s, 16MB
Cache
Optical Drive Single Drive: Bluray Disc Drive (BD/DVD/CD
burner w/double layer BD write
Monitors 20 inch E207WFP
Widescreen Digital Flat Panel
http://www.dell.com
….
Wikipedia
micron = 10-6 meters
The feature size of an integrated circuit is indicated by the width
of a "wire," measured in microns (one micron is one millionth of a
meter). Analysis and Design of Analog Integrated Circuits (4th Edition)