Greetings =) Well, I scheduled both exams this coming saturday (18th) and I am a nervous wreck as I have no idea to really expect on this test. I have about an intermediate level of understanding on hardware.. I can build computers, install/configure windows OS.. I also have memorized all IRQ, I/O, and DMA assignments. I was curious of a few things:

1) I have around 10+ prep sheets/software programs that I have been cycling through and I saw questions like: "How many options is on the main menu of Microsoft Anti-Virus?".. I seriously hope there aren't questions like that.

2) What would be the main focus of material that I would be tested on for Core and OS? For example, on the OS test.. is it mostly NT or Win 9x or just a mix?

Well, I hope I pass anyway.. been dealing with computers in a hardware/programming level since I was 7 (14 years).. and I am a little tired of working at the prison (correctional officer)

I would appreciate all feedback =)

__________________
Sincerely,
Aaron T. Freeman
- TN Correctional Officer at NWCX

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quote:

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1) I have around 10+ prep sheets/software programs that I have been cycling through and I saw questions like: "How many options is on the main menu of Microsoft Anti-Virus?".. I seriously hope there aren't questions like that.

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__________________
A lazy idiot is the hardest worker. He tries to find the easiest path and always fails.
-SomeGuy-

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I probably should have added.. I read the All-In-One A+ Certification 4th Edition book written by Michael Meyers (hopefully not the killer from Holloween :P).. I must say that book is great.. I read that book to build a foundation on my studies, took only a couple of weeks to read all 1110 pages. I will take a look at examdrill. Thanks for the input.

__________________
Sincerely,
Aaron T. Freeman
- TN Correctional Officer at NWCX

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Oh and maybe you can help me understand something that is confusing me in IRQs. With a dual cascade i8259 setup (IRQ 0-15).. IRQ 2 and 9 are on the same signal.. so how can IRQ9 be given to a device? I thought that IRQ2 and IRQ9 are reserved?

__________________
Sincerely,
Aaron T. Freeman
- TN Correctional Officer at NWCX

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No. IRQ 9 is open for use. IRQ 2 is reserved.

See... Computer designers are surprisingly reluctant to change. Change leads to new things being incompatible with old things. So many aspects of a PC are the same as they were when the original IBM PCs and the original 8088 chips were released.

We still have the old conventional memory, we still have the old COMM ports, and we still have the old 8 IRQ setup.

At one point they realized that 8 IRQs weren't quite enough for all the devices being installed in machines so they added 8 more. Unfortunately, the system didn't know how to access the extra 8 IRQs because they were set up to only use 8. So what happened was they made one of the original IRQs into something like a "bridge". IRQ 2 was set aside so that it connected you with IRQ 9. Once you got above IRQ 7, the original highest IRQ, you could access the other higher IRQs. This is called "cascading".

Here is how I think of it... Imagine you have a house with 8 rooms and no doors. You can't leave the house so you have to live with only having 8 rooms to move around in. Let's say one day you decide you need more rooms, but you can't add any more rooms to your existing house and you can't go to another house.

There is an identical house next to yours but it too has no doors. So, what you do is, you set up a teleportation device in Room 2 that instantly teleports you to Room 9 in the other house when you enter Room 2. Now, Room 2 is no longer available for use by you because it is occupied by that teleporter, but now you have 8 more rooms to live in.

Stupid analogy, but it's more or less how it works.

A similar method was used in DOS memory management, first with blocks of reserved memory set aside to bridge with expanded memory, then with high memory used to allow DOS to interact with extended memory. They're little sleight-of-hand tricks that allowed designers to get more out of a system without redesigning the whole thing to remove restrictions.

__________________
A lazy idiot is the hardest worker. He tries to find the easiest path and always fails.
-SomeGuy-

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Eek, I just thought of a better analogy... Should've thought of it before.

Imagine you have a highway with 8 lanes of traffic. During rush hour those 8 lanes are totally full and you have traffic jams. So you turn one lane into an off ramp that merges with another 8 lane highway. You've just lost one lane from the original highway, but gained 8 more on the other one.

That's a better analogy because IRQs are alot like lanes on a road, they are routes by which commands between the CPU and various devices are sent.

__________________
A lazy idiot is the hardest worker. He tries to find the easiest path and always fails.
-SomeGuy-

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I dont see how that is electronically possible, but I dont really care =) So IRQ2 is reserved to get to IRQ9, but IRQ9 is always open, like 10, 11, and 12.. sounds fair enough. Appreciate it =)

__________________
Sincerely,
Aaron T. Freeman
- TN Correctional Officer at NWCX

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quote:

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I dont see how that is electronically possible, but I dont really care

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__________________
A lazy idiot is the hardest worker. He tries to find the easiest path and always fails.
-SomeGuy-

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I was actually just looking at that, but I just put in the back of my mind that more than 1 device can be given the same "open" IRQ. But that clerifies it a bit more =)

Anything else other than IRQs that I should pay more attention to?

__________________
Sincerely,
Aaron T. Freeman
- TN Correctional Officer at NWCX

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Another thing (especially with my other machine doing it).. was something in my prep exam software that talks about HDI (Head to Disk interface) where the HDD is making a grinding noise.. what triggers that and how can that be solved? It wouldnt go into detail.

__________________
Sincerely,
Aaron T. Freeman
- TN Correctional Officer at NWCX

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