-
After installing the cards,
there are three parameters to configure, IRQ
, IO address
, DMA
.
-
You must make sure there is no
conflict between two devices
being assigned the same
parameter value.
-
You can configure a device by
assigning it a unique IRQ
, IO address
and sometimes a DMA
channel.
-
You can configure a device by
adjusting jumpers or by using a configuration disk.
-
You can view all your device
configurations by viewing Device
Manager
in Windows environment.
-
Interrupt
Request
-
IRQ
Range
-
Cascade
IRQ
-
Unique
IRQ
-
IRQ
Table
-
IO
Address
-
DMA
Channel
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|
-
Interrupt Request (IRQ
) is a unique number that is assigned to any device communicating with the
processor.
-
The
processor can be interrupted momentarily from its current work by any
device that needs its attention on the computer.
-
All devices
communicating to the CPU
are assigned an IRQ
number ranging from IRQ0 to
IRQ15.
-
IRQ
2 and IRQ 9 are defined as a
cascade and can be thought of as being the same IRQ. You can either assign
IRQ2 or IRQ9 but not both.
-
Since all computer have certain
devices
built in by default, such as
Keyboard, Floppy, Math coprocessor
, Hard drive etc certain IRQ
are pre assigned to these
standard devices.
-
No
two devices
can
share an IRQ
number,
or the processor will confuse between the communicating devices and both
devices may not work.
IRQ
Table
Here is a table
listing the total number of IRQ
’s within your system and the devices
that can and do use those
particular IRQ’s. You will notice some of the IRQ’s are automatically
associated with certain system devices such as keyboard
and the floppy drive
. You will also notice that some of the IRQ’s are available and can be
configured for new devices installed within your system. The IRQ ,IO Address
and DMA
address tables must be memorize
for the A plus exam.
-
You
can imagine the IO Address
to
be like your mail box where you can place your letter in it for the mail
man to pick up and you can also pick up letters delivered by the mail man.
-
All devices
communicating with the CPU
require an exclusive region in
memory
to be defined for the
communication
to take place.
-
Each device must be assigned
its own unique IO address
.
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|
|
|
|
|
|
|
|
|
|
|
|
|
|
*
Indicates that IO address is optional for that device and can be
changed
|
|
DMA
Channel
-
Direct Memory Access (DMA
) channel allow devices
to access the memory
without the permission of the
CPU
.
-
You can think of the CPU
as having given a trust token
to a DMA
usable device to allow it to
access the memory
.
-
This enables devices
, which use DMA
to operate much faster then
non-DMA devices.
DMA
Channel
Table
-
You
can assign an IRQ
to
any device either by setting up the correct jumper
settings
on the device or by using the configuration disk made available with the
device.
-
Cards,
which can be configured with Jumpers, are usually older ISA
cards.
-
Notice
all of the normally available IRQ
’s are listed.
-
Make sure there are no
conflicts between set IRQ
’s
-
Notice that there is a limited
number of IO address
made available for this card.
-
You
must use the configuration disk that comes with card or peripheral that
you have purchased.
-
The
manual
for
the device will inform you of the name of the configuration file and
operational instructions
-
If
you do not want to use the default plug and play features of the card,
then you usually must run the configuration disk in either DOS
or
Command prompt environment.
-
There
is a welcome screen that allows you to choose to configure the card or
view its current settings.
-
After
you pass the initial welcome screen, then you can choose to change the IRQ
configuration.
-
Notice
the stars on some of the IRQ
’s indicating that the IRQ is
currently in use by another device.
-
The
IO address
can
be changed in the same way as the IRQ
’s are changed.
-
Notice
that the IO addresses are all hexadecimal
numbers.
-
You can view your current
configuration of the system in the Device Manager
in windows 95/98/NT/2000
-
To
view your current system configuration in device Manager, Click on startà
Settings
à Control Panel
and
then click on the system icon Windows 95/98
/NT/2000.
-
Device Manager
is the main option made
available to you in the system properties of Windows 95/98
/2000.
-
Make sure the view
device by type radio button is selected.
-
Click on properties to view the
different device configurations
-
On the Hardware
screen click on the Device
manager button.
-
You
can now view the current configuration for all the devices
in
your system.
-
You
can also change your view in Device Manager
to
view the different connection types like the IRQ
’s.
Questions
1) What IRQ
is given to COM1?
a)
2
b)
3
c)
4
d)
5
e)
6
2) What IRQ
is given to LPT2?
a)
2
b)
3
c)
4
d)
5
e)
6
3) What IRQ
is given to floppy Controller?
a)
2
b)
3
c)
4
d)
5
e)
6
4) What IRQ
is given to PS2 mouse
?
a)
12
b)
13
c)
14
d)
15
e)
10
5) What IRQ
has been cascaded with IRQ9?
a)
2
b)
3
c)
4
d)
5
e)
6
6) What is the IO
address
of COM
4?
a)
2B0
b)
2E8
c)
2F8
d)
3E8
e)
3F8
7) What is the IO
address
of XT hard drive
?
a)
2B0
b)
320
c)
278
d)
3F0
e)
274
8)What is the IO
address
of LPT1
?
a)
270
b)
278
c)
2F8
d)
378
e)
3F8
9) What is the
DMA
address of the floppy controller?
a)
1
b)
2
c)
3
d)
4
e)
5
10) What method
can be used to manually
configure a network
card?
a)
Configuration Disk
b)
Jumpers
c)
Switches
d)
Connectors
e)
Cable
11) What is the
device configuration tool inside windows?
a)
Tool adder
b)
Device Manager
c)
Device adder
d)
IRQ
Finder
Answers
-
C
-
D
-
E
-
A
-
A
-
B
-
B
-
D
-
B
-
A,B
-
B
