1. Compsci 210 Tutorial Five

2. agenda
Lc-3 simulator practice
Some exercises from past test

3. LC-3 simulator & LC-3 editor
CompSci Semester One 2016

4. LC-3 simulator & LC-3 editor
You can edit your program here using binary code, hexadecimal code and assembly code. 
After finish editing, you can export to .obj file which can be run by LC3 simulator.

5. LC-3 simulator & LC-3 editor
virtual computer which execute assembly code
Simulator
CompSci Semester One 2016

6. LC-3 Notes The simulator and the editor are separate programs
The simulator is available for Windows (also Linux/Java/etc)
The lab computers should have LC-3 included
The LC-3 software can be executed from a flash drive
Download from :
Goolge: lc-3 simulator
canvas if needed
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7. The LC-3 Files
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8. The LC-3 Files
After installation, you will see 2 exe programs (windows): LC3Edit.exe and Simulate.exe.

9. LC-3 Editor
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10. LC-3 Editor The editor is used to enter your LC-3 instructions
You will save your programs into the .asm format
The editor will also assemble your .asm files into .obj files which can be run on the simulator

11. example.asm
.ORIG x3000 LD R2, ZERO LD R0, M0 LD R1, M1 LOOP BRz DONE ADD R2, R2, R0 ADD R1, R1, -1 BR LOOP DONE ST R2, RESULT HALT RESULT .FILL x0000 ZERO .FILL x0000 M0 .FILL x0004 M1 .FILL x0803 .END
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12. LC-3 Simulator

13. LC-3 Simulator
The simulator is used to execute your assembled LC-3 machine code
You will load the .obj files you create into the editor
The editor gives you a very detailed view of what is happening as your machine code is executed

14. Lc-3 simulator
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15. Example: LC-3 ADD Instruction
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16. Demonstration Complete the following tasks in LC-3.
Write a program in the LC-3 Editor.
Assemble a program in the LC-3 Editor.
Load and execute a program in the LC-3 Simulator.
Set breakpoints in the simulator to pause execution.
Step forward through your executing program one line at a time.
Modify a register value during program execution.

17. Just do it
the LC3-Simulator on the lab computers is located at C:\Program Files (x86)\lc3simulator
here is the link for the LC-3 Simulator:
3_simulator.html
All the examples can be found from canvas:
torials_Ben_Thursday
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18. Assembly language examples
A program to multiply a number by the constant 6
Number * 6
A subtraction program
subtracts the number in the variable SECOND from FIRST and stores the result in DIFF
diff = first - second
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19. Q20 from last test
The great explanation from josh on canvas:
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20. What is the 8 bit 2’s complement binary representation of -35
Decimal Value: -35
35 / 2 = 17 R 1
17 / 2 = 8 R 1
8 / 2 = 4 R 0
4 / 2 = 2 R 0
2 / 2 = 1 R 0
1 / 2 = 0 R 1
Calculate 2’s complement: →
Answer:

21. What is the result of adding these unsigned binary numbers: 10110101 + 1011
“ ”:
left pad any numbers so both have the same number of bits
1011 =
Now align them vertically, and add
1 + 0 = 1, = 0 (with a carry), Carry + 1 = 0 (with a carry)
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22. What is the result of subtracting these unsigned binary numbers: 10110101 + 1011
“ ”:
1011 =
1 - 1 = 0, = 1 (with a carry “-1” from left side)
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23. If 0010100.101 is a binary fractional number what is its decimal equivalent
convert to decimal
= −1 + 2 −3 =
=20.625
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24. Questions
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