Arab Open University
T103
Computer Organization and Architecture
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Tutor-marked Assignment 1
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Spring semester 2013
Cut-off date: 30/04/2013
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Instructions to the students:
Please read carefully the following instructions:
This TMA contains four distinct parts with 6 different questions. You should answer all these questions.
Read carefully each question before editing your answer.
Respect the good academic conducting by:
- Avoiding plagiarism,
- Using your own words,
- Adding References,
- …
Part 1: Discovering computer organization and architecture (10 Marks)
1) Figure 1 shows a photo of an Intel ATX Motherboard.
a) Search on the internet to find a definition for “Motherboard”. (2 Marks)
b) Identify: the CPU socket, the RAM Memory Banks, the PCI slots, External Ports and the AGP connector by giving its identification number shown on Figure 1.
(5 Marks)
c) What do the terms RAM, PCI and AGP stand for? (3 Marks)
Figure 1. Photo of an Intel ATX Motherboard
Part 2: Working with numbers (20 Marks)
2) Convert each of the following numbers to the destination radix (show all your calculations and conversion steps).
010011011112 = (……………)16 (2 Marks)
7408 = (……………)2 (1 Marks)
22010 = (……………)6 (3 Marks)
8510 = (……………)2 (2 Marks)
3) Use signed magnitude arithmetic to add 01100111 to 10011111(explain and show your detailed calculations clearly). Do we have an overflow? Why? (6 Marks)
4) Show how the number -58 is represented in binary if the computer uses a simple 14-bit floating point representation (1 sign bit, 5 bits for exponent and 8 bits for the significand) with excess-16 bias. (6 Marks)
Part 3: Boolean algebra and digital logic (15 Marks)
5) Consider the following function:
F(a,b,c) = + c + +
a) Use DeMorgan’s law and the distributive law to find F(a,b,c) in a sum of products form. Show your calculation steps clearly. (5 Marks)
b) Use Boolean identities to represent F in its simplest form. Show your calculation steps clearly. (5 Marks)
c) Use NOT, AND, OR gates to draw the logical diagram of the simplified F (Some of the suggested gates might not be used). (2 Marks)
d) Use only NAND gates to draw the logical diagram of the simplified F. (3 Marks)
Part 4: Working with MARIE (15 Marks)
6) We need to build a program that does the following:
- Adds two numbers present in memory s X and Y.
- If the result is positive or equal zero, stores it at memory address Z.
- If the result is negative, stores it at memory address Z and then sends it to output (to screen).
a) Use MARIE assembly to write the previous program. Consider that the values stored at addresses X, Y and Z are 510, -710 and 010 respectively. Use “org” instruction to start your program at address 100. (8 Marks)
b) Use MARIE Simulator to run your program. Add a screenshot of the simulation’s results (A screenshot for the MARIE Simulator window). Insure that the output is represented in Decimal and that the of address Z is well shown. (2 Marks)
c) After running the code, what is the of the following registers in hexadecimal: AC and MBR? (2 Marks)
d) After running the code, what is the value stored at address Z in decimal, hexadecimal and binary? (3 Marks)
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Good Luck!
