Arab Open University
T103
Computer Organization
and Architecture
Part1: Discovering computer organization and architecture
1)
The electronic device that revolutionizes
computers is the “Transistor”. In no more than 50 words, give a brief
explanation of a transistor.
Hint: The student is advised to use a reliable
resource.
2)
To understand how a computer works, the
computer machine is usually divided into a hierarchy of seven levels.
a)
Give a name for each of these levels.
b)
Link each of the following to its appropriate
level: A binary instruction, the Von-Neumann execution cycle, an instruction
written in Visual Basic, Windows 8,Microsoft PowerPoint, an AND gate, an
assembly instruction.
Part2:Working with binary numbers
3)
Converteach of the following numbers tothe
destination radix (show all your calculations and conversion steps).
§
AF0916= (……………)8
§
25410 = (……………)2
4)
Consider the following hypothesis: “At
the digital logic level of a computer system, all decimal numbers are
represented in binary (base 2). However, the same binary number can be
equivalent to different decimal numbers (base 10) if treated by different
binary numbering systems”.The aim of this exercise is to check the authenticity
of this hypothesis.
a) What is the decimal equivalent of the binary number“100101101” , if treated
by:
a.1) A 9-bit
unsigned whole numbers system?
a.2) A 9-bit signed
magnitude system?
a.3) A 9-bit
Complement 2 system?
a.4) A 9-bit floating point system where the binary
number isdivided, from left to right, to the following fields:
§
Sign bit : 1 bit length,
§
Exponent: 4 bits length (without
biasing),
§
Mantissa: 4 bits length.
b)
What can you say about the initial
hypothesis? Is it correct?
Part3:Boolean
algebra and digital logic
5)
During a T103 lab session, the students were
asked to implement the simplest circuit of the following logical function:
.
Hence, they were firstly asked to suggest its simplest logical diagram. A
student called Simonsuggested the following logical diagram:
The aim of this part is to prove that Simon’s suggestion is correct but not
the simplest and that F can be implemented using only one gate.
a)
How many gates do we need to implement
the logical diagram suggested by Simon?
b)
Refer to Simon’s logical diagram above to
find the Boolean expression of its output function Fs. Then, use
Boolean identities and algebra to represent Fs in its simplest sum
of products form.
c)
Prove that Simon suggested a correct
logical diagram (i.e. F and Fs are logically equivalent).
Note: Use the method you find convenient.
d)
Deduce a logical diagram for the function
F much betterthan Simon’s (in terms of number of gates).
Part 4:Working
with MARIE
6)
We need to build a program that does the
following:
-
Reads two decimal numbers (entered by the user) and stores them at
addresses X and Y respectively.
-
if (M[X]>10) then
§
SubtractsM[Y] fromM[X] (i.e.: M[X]-M[Y])
§
Stores the result at address Z
§
Outputs the result.
-
Else (i.e. M[X] <=10)
§
AddsM[X] toM[Y]
§
Stores the result at address Z
§
Outputs the result.
a)
Use MARIE assembly language to write the previous
program.Use “org” instruction to start your program at address 100.
b)
To verify the correctness of your
program, use MARIE Simulator to run it three times taking into consideration
the following points:
-
For the first run, consider that M[X]
> 10.
-
For the second run, consider that M[X]
< 10.
-
For the third run, consider that M[X] =
10.
-
For each run, add a
screenshot of the simulation’s result (A screenshot for the MARIE Simulator
window). Ensure that memory addresses X, Y and Z and their contents(M[X], M[Y]
and M[Z]) are well shown as well as the output in Decimal.
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