-
This
module
was
designed to introduce you to the typical computer regardless of vendor and
present you with an overview of all the aspect of the system design.
-
In
order to have the big picture one must recognize all of the individual
components of the computer and be visualize where it fits in to the whole
computer. We will be
discussing in detail each of components introduced in this module
in
future modules.
-
System
Processor
-
CISC
and
RISC
-
System
clock
-
Over
clocking
-
System
Busses
-
System
Memory
-
ROM
|
-
RAM
-
Cache
-
CMOS
-
External
Ports
-
External
Busses
-
Math
Co-processor
-
System
Peripherals
|
-
Processors
can understand, organize the commands- instructions
and
perform them in which is referred to as processing
-
Processors
are often referred to as CPU
(Central
Processing Unit), which is not strictly correct.
-
CPU
is
the major component of a processor.
-
The
abilities of your processor define your system capabilities, e.g. data bus,
clock speed.
-
Processors
are integrated circuits (IC
’s) full of transistors
ranging
from 30 thousand transistors in the 8088 to 45 million transistors in the
Pentium
4.
-
There
are many different manufacturers of processors including Intel
, AMD
, Cyrix
, and Motorola
, but the PC gold standards is
Intel.
CISC
and
RISC
-
The
performance
of
the system is a complex mixture of system clock speed, the data bus size and
the instruction load on the system called instruction set.
-
There
are 2 separate instruction load systems, CISC
and
RISC
-
CISC
stands
for Complex Instruction Set Computer.
-
CISC
performs
a large number of complex instructions
, which increases the system load on
each instruction therefore reducing the system speed.
-
CISC
processors are usually used in
standard IBM
compatible
PC’s
-
RISC
stands
for Reduced Instruction Set Computer.
-
RISC
speeds
up its overall progress and performance
by
performing small instructions
, reducing the systems load on each
instruction therefore increasing the system speed.
-
Motorola
RISC
processors
are also used in Apples computer systems.
-
RISC
Processors are usually the high
end Pc such as Servers e.g. Digital Alpha machines and MIPS SGI machines.
-
The
system clock is like the heartbeat of your system is measured in MHz.
-
The
whole system is synchronized
on
the clock beat, the faster it beats the faster your processor will work and
if it doesn’t pulsate, your system will halt.
-
There
are two separate clock speeds, internal clock
speed,
and external clock
speed.
-
The internal clock
speed is the speed at which the
components inside the processor communicate with each other including CPU
, cache
, and registers, ALU
.
-
The external clock
speed is the speed at which the
processor communicates with the other devices
on the system including the RAM
.
-
The general system clock speed in
multiplied or divided by certain factors to meet the requirement of certain
sub-busses
on the system board
as shown in the table.
-
Over
clocking
gives
you the ability of improving the performance
of
your processor by increasing its clock speed beyond its design
specifications.
-
Since
the processor is doing more work it will generate more heat and need to have
good cooling.
-
You
can usually over clock the processor by changing a setting on your system
board
-
It
can cause the destruction of the CPU
if
the right precautions are not taken.
-
Celeron
processors are especially over
clocked up to twice their normal speeds.
1.
Data bus
2.
Address bus
3.
Control bus
-
The
data bus is responsible for transferring data from the processor when
communicating. The bigger the data bus, the more data that can be
transferred on each clock beat.
-
The
address bus defines the total amount of memory
that
can be addressed by the processor.
-
The bigger the address bus, the
more data that can be addressed, 8088 has 20 pin address bus which handles
1MB of RAM
, and the 386
has 32 pin which handles 4GB of
RAM.
-
The control bus
is designed to control the
overall progress and control of the system, the system clock is part of the
control bus
-
Memory is distributed throughout
the computer system and cannot be compartmentalized
.
-
Memory comes in all sizes speeds
and prices reflecting its utilization within our system.
-
It comes in two main types RAM
(Random Access Memory) and ROM
(Read
Only Memory).
-
Most devices
have both ROM
and RAM
on board to improve performance
e.g. SCSI
, VGA
.
-
ROM
=
Read
Only
Memory
-
ROM
chips
are used in older PC (up to 486
systems)
and cannot be overwritten. ROM chips are non-volatile memory
-
Flash
RAM
is
used in more modern system (Pentiums and above).
-
ROM
chips
are usually soldered on system board
-
PC
requires small quantities of ROM
(64KB)
for low-level hardware instructions
-
These
instructions
are
referred to as the BIOS
(Basic
Input Output System), which are the startup
instructions,
or Firmware
-
RAM
=
Random Access Memory
-
There
are two main types of RAM
, dynamic and static
-
Static
RAM
is
more expensive then dynamic RAM
-
RAM
is
used as workspace by PC and is volatile (losses data when power is switched
off).
-
Dynamic
RAM
hardware
Can be upgraded
-
PC’s
require large quantities of dynamic RAM
-
Increasing
the RAM
in
a system would significantly improve system performance
-
Usually
sold as SIMM
’s
(Single Inline Memory Module) or DIMMs (Dual Inline Memory Module).
-
There are a multitude of RAM
designs for the different system
boards and chip sets in the market.
-
Cache
is very fast static RAM
memory
that
interacts with the CPU
when
performing instruction to enhance the systems response time.
-
Typical
RAM
has
access times of 50-70ns but cache
access
times are 7-15ns
-
Obviously
the more cache
we
have within our system, the faster the performance
of
the system.
-
Cache
is very expensive and a balance has to be reached on a system between system
performance
and
cost. There are 2 categories of cache
, L1 (built on the CPU
chip)
L2 (external to CPU).
-
Typical
quantities
of L1 cache
range
from 8KB to 32KB in size and typical quantities of L2 cache
range
from 128KB to 4MB.
-
CMOS
= Complimentary Metal Oxide
Semiconductor.
-
Soldered on system board
.
-
Typically 64 bytes in size.
-
Stored all the current settings
of our system including HD
, FD
, time and date setup.
-
Requires a battery
located on all system boards to
hold settings data.
-
Located
at the back of your computer.
-
Designed
to communicate directly to peripherals
including
keyboard
, mouse
, printers
, modems
, scanners
, CD
writers
etc.
-
They
include PS/2
port,
serial ports, parallel port
, and USB
ports.
-
They
are generally not very fast.
-
They
can implement hot swapping.
-
IEEE
1394
can be added to most system with
very high speeds.
-
Expansion
slots located on your system board
allow
us to expand our systems functionality by connecting expansions cards
such
as network
cards
, modems
, soundcards
etc.
-
There
are a variety of designs for expansion slots
, which have been evolved over the
lifetime of the computer.
-
The
expansion slots
come
in a variety of different shapes, sizes, speeds and capacities.
-
These
expansion slots
include
ISA
, EISA
, MCA
, VESA
, AGP
, and PCI
, with PCI being the most popular
design on the latest systems.
-
PCMCIA
is the standard on Laptop
systems.
-
Performs
mathematical operation sometimes referred to as floating
point
unit (FPU
) operations.
-
Only
utilized by applications
designed
to use its mathematical capabilities e.g. AutoCAD.
-
It
came as a separate chip for older systems (8087, 287, 387
,487).
-
It
is built on board all processors newer then 386
systems.
Given x87 name (8087,287,387
,487)
-
Math
co-processor is built in 486DX systems and above
-
Devices connected to our system
that sometimes interact directly with the user to accomplish the task at
hand.
-
Most peripherals
are external including keyboard
, mouse
, printers
etc.
-
Internal devices
include storage devices, sound
card
, SCSI
card, NIC card
, etc.
-
The internal devices
are usually faster then the
external peripherals
.
Questions
1) What Does CISC
Stand for?
a)
Complex Instruction Selected Computing
b)
Complex Instruction Set Computing
c)
Common Instruction Selected Computing
d)
Complex Inner Selected Commands
e)
Complex Instruction Set Commands
2) What does RISC
stand for?
a)
Ram Inner Set Computing
b)
Reset Instruction Setup Calculations
c)
Reduced Instruction Set Computing
d)
Repeat Instruction Setup Computing
e)
Reduced Instruction Set Commands
3) What computer
use RISC
(choose all that apply)
a)
MIPS systems
b)
DEC Alpha
systems
c)
PC IBM
compatible
systems
d)
SUN Microsystems
4) What does the
data bus do? (choose all that apply)
a)
Transfer
data between the processor and RAM
b)
Transfer
data between peripherals
and RAM
c)
Controls the system clock
d)
Addresses the RAM
5) What is the
internal clock
speed on a computer ?
a)
Clock speed on the system board
b)
Clock speed on the processor
c)
RAM
clock speed
d)
Bus clock speed
6) Which bus
determines the maximum amount of memory
can be used on your computer
a)
Data bus
b)
Control bus
c)
System bus
d)
Address bus
e)
Transfer
bus
7) Why would you
over-clock your system?
a)
Improve processor performance
b)
Speed up the RAM
c)
Improve Bus speeds
d)
Speed up CMOS
e)
Over heat the system
8) Which of the
following will improve processor performance
? (Choose all that apply)
a)
Increase system RAM
b)
More processor cache
c)
Large data bus
d)
High clock speed
e)
Improved cooling
9) What does RAM
stand for?
a)
Random Access Memory
b)
Read
Access Make
c)
Read
Access Memory
d)
Random Available Memory
10) Which chip
contains the BIOS
?
a)
RAM
chip
b)
CPU
c)
ROM
Chip
d)
Cache
11) What type
memory
is Cache?
a)
DRAM
b)
SRAM
c)
SDRAM
d)
VRAM
e)
WRAM
12) Where is L1
cache
located?
a)
On the system board
b)
On the video card
c)
On the system processor
d)
On the SIMM
13) Where is L2
cache
located?
a)
On the system board
b)
On the video card
c)
On the system processor
d)
On the SIMM
e)
On the DIMM
14) What is the
typical size of your CMOS
?
a)
64 KB
b)
128 KB
c)
256 KB
d)
8KB
e)
16KB
Answers
-
B
-
C
-
A,B,D
-
A,B
-
B
-
D
-
A
-
A,B,C,D
-
A
-
C
-
B
-
C
-
A
-
A
|
