# Homework Help: Computer architecture problem solving.

1. Aug 29, 2008

### FlipStyle1308

1. The problem statement, all variables and given/known data

1. A man bought a computer and when he booted it up he realized that the OS is not loading into RAM. Can you suggest what could be wrong with the computer? (Yes, the computer was plugged into the outlet and the power was turned on.)

2. Describe the process by which the CPU multiples 2 by 5, assuming that numbers are stored in cache.

3. Draw a flow chart for finding the smallest of the 3 given numbers using standard flow chart symbols.

2. Relevant equations

N/A

3. The attempt at a solution

1. OS is corrupted and needs to be reloaded.
2. I believe an algorithm is used but I do not know how to word my answer.
3. I know the symbols, but I just need help setting the whole thing up.

2. Aug 29, 2008

### mgb_phys

You need to break things down into much smaller steps (actualy that pretty much sumarises engineering!)
1, What are the steps for getting the OS into ram, where isit from, what is involved?

2, Imagine the CPU as a factory with little workers in it (the oompa-lumpa model), what are the steps to get the data in, where does itgo, what has to happen next, where does the answer go

3, Don't worry about the symbols initially, how would you work out the sum on paper? Now write down every step, now convert to symbols (should probably just be a loop with a couple of 'ifs')

3. Aug 29, 2008

### FlipStyle1308

To be honest for the first two hints you have given me, I have no idea where to begin. My class is actually a chemistry computer class, and my instructor just gave us a problem set, and there is no section of the notes to reference to when attempting these problems, and we do not have a textbook or manual for this course. All I have are lecture slides to work with, and these concepts have not been discussed. I really would like to attempt to solve the problem, so I was wondering if there is any other way you can help my solve this. Thanks.

4. Aug 29, 2008

### mgb_phys

The machine has to
1, Find the disk drive
2, Load the boot sector code that tells it how to read a disk
3, Read the disk and find the operating system
4, Load the operating system into ram
5, Execute the program in ram

1, You have to read the numbers 2 and 5 into the cpu (google for "register" )
2, execute the multiply instruction
3, copy the answer back to memory

5. Aug 29, 2008

### Dick

If this is a chemistry computer course, those questions are somewhat out of line. 1) has any number of solutions falling under the general headings of i) hardware failure and ii) software corruption (as mgb_phys and you have suggested). 2) multiplication is generally implemented in hardware as a shift-and-add process. Assuming you know how to add. Which is not necessarily trivial either considering signs and carries. 3) is the only one that might actually be relevant if you want to design your own algorithms. Label the three numbers as n1, n2 and n3. Start with a box that says "n1>n2?" with two outgoing lines labeled "yes" and "no". Connect those to other boxes asking questions about the numbers and make sure each branch when followed to the end yields the minimum. Now hope the next set of questions is more related to computers in chemistry.

6. Aug 29, 2008

### FlipStyle1308

Thank you for all of your help! Yes, I hope the next set or problems actually relates to chemistry lol.