Remebering IRQ's and COM Ports!!!!! ??????

Kerry_20

I got this from a friend by email.... Can someone explain it to me!!! Do you guys know any other good methods to learn this.


First step:-
- I LOVE YOU :- 1-4-3 ( I=1,LOVE=4,YOU=3)
I=ONE LRTTER=1
LOVE=FOUR LETTERS=4
YOU=THREE LETTERS=3

{ 1-4-3 }

NOW, FIRST AND LAST ARE COM-PORTS
MIDDLE IS IRQ FOR COM1 AND COM3

NOW, FIRST(1) IS "F",AND LAST(3) IS "E"
MIDDLE IS 4 (JUST 4-1=3)

NOW, I/O ADDRESS FOR COM 1 =3F8h (03F
COM 3 =3E8h (03E

SECOND STEP:-
JUST NUMBERING ORDER (2-3-4)

NOW,FIRST(2) AND LAST(4) ARE COM-PORTS
MIDDLE IS IRQ FOR COM-PORTS ie

NOW,FIRST(2) IS "F" AND LAST(4) IS "E"
MIDDLE = 3 ie 3-1=2

NOW I/O ADDRESS FOR COM 2 =2F8h (02F
COM 4 =2E8h (02E


--Kerry

STexams

Well, it's one method of word association.
I just wrote down the charts until I could write them from memory. That seemed easier than trying to memorize a word association table.

garv221

Tht method without a doubt is too confusing...

Webmaster

Just do our DMA IRQ I/O quiz until you can dream them:

www.techexams.net/coexam/start.php?exam=apluscore3

bakachan

For IO memory ,
com1odd number matches,
com2even number matches
com3odd number matches,
com4even number matches,
then the alphabet goes backwards. so it's com 1 is 3f8, com2 is 2f8, com3 is 3e8, and com4 is 2e8.


for irq's i just think of 1 and 3 and 2 and 4 as matched pairs.
4 doesnt have the irq of 4 therfore 4 must have irq of 3

crc32

Webmaster wrote:

Just do our DMA IRQ I/O quiz until you can dream them:

www.techexams.net/coexam/start.php?exam=apluscore3

This question seems odd on the practice exam

1. How do CRT's work?

a. A beam of light passes in front of the screen and produces and image on the screen
b. A beam of light passes diagonally across the screen and produces and image on the screen
c. A beam of light passes behind the screen and produces and image on the screen
d. A beam of light flashes once, and produces and image on the screen



None of the answers are appropriate as it is an stream of electrons hitting a phospher that create light. I really don't feel comfterbal with this question.

Another odd one is

3. What must you do before working on a CRT?

a. Put on an anti-static wrist strap
b. Remove your anti-static wrist strap
c. Put on gloves
d. Touch the capacitor

It seems odd cause it assumes the tech is already dumb enough to have a wrist strap
on to begin with. I think the most important thig is to stay away from that killer
suction cup and not playing with any capaciters. Thus I would have said put on gloves would be the logical thing to do. And certainly you'd want to avoid capaciters.

Shaithis

That Suction cup does not last nearly as long as you think. It is much different on TV and Monitors. Most monitors the voltage drops almost immediately. But on a TV if you hit under the suction cup for 10-20 minutes after you turn off the TV you are goping to get nailed.

And about the what should you do before you work on a monitor. That one is tricky cause they do not say wiether the monitor is on or off. If it is off you should have a ground strap on. If it on you do not want the group strap on.

crc32

Shaithis wrote:

That Suction cup does not last nearly as long as you think. It is much different on TV and Monitors. Most monitors the voltage drops almost immediately. But on a TV if you hit under the suction cup for 10-20 minutes after you turn off the TV you are goping to get nailed.

And about the what should you do before you work on a monitor. That one is tricky cause they do not say wiether the monitor is on or off. If it is off you should have a ground strap on. If it on you do not want the group strap on.

It is true that most CRTs these days are self draining when they are powered down as
saftey feature you however are not allowed to assume your working with such a monitor.

The thing to remember is a ground strap is designed to protect sensitive electronics from you not the otherway around. Thus because of the high charge that can be built up on a CRT you should never try to ground your self in any way and this is what the question is driving at. Its implying the correct answer is to remove your wrist strap before working on the monitor, but this seems odd cause most techs woulden't be wearing a strap to begin with. And for that matter you shoulden't really be working on a live monitor period.

Webmaster

I don't know what the monitor questions have to do with this topic, nevertheless... The A+ Display TechNotes and the Display practice quiz are one of the few things I did not write myself. They are written by Tracey Rosenblath (try a search on Amazon).

I agree with you to a certain amount... and will rewrite the first question, but:

None of the answers are appropriate

It seems odd

You will probably have that on the real exam as well. That is the reaction CompTIA exams tends to create. There are several questions on the exam that don't have 'appropriate answers' or have more than one appropriate answer while you can only choose one.

It seems odd cause it assumes the tech is already dumb enough to have a wrist strap on to begin with.

He might have been working on other computer parts.... Not wearing a wrist strap when working on monitors is something that is stressed in various study material for the A+ exam... guess why