Run the assembly program:
CPU 8086
ORG 0400H
SECTION CODE:
MOV AX, 0460H
MOV SP, AX
MOV AX, 1
MOV BX, 2
MOV CX, 3
MOV DX, 4
MOV WORD[DATA1], 7
PUSH AX
PUSH BX
PUSH CX
PUSH DX
INT3
POP AX
POP BX
POP CX
POP DX
POP WORD [SUM]
INT3
SECTION DATA:
DATA1 DW 7,9,10,11,12
SECTION BSS:
SUM DW 3
Demonstrate the following:
1) Run the program. It will run up to the first INT3 (break point). at this time, show and write the content of stack, register, and variables.
2) Comment out the first INT3. Run the program again. At this time, show and write the content of stack, registers, and variables
To run the assembly program, we need to first assemble and link it using an appropriate assembler like TASM (Turbo Assembler) or NASM (Netwide Assembler). Then, we can execute the resulting executable file.
Here's a step-by-step demonstration of running the program and examining the contents of the stack, registers, and variables at different points:
1) Run the program up to the first INT3 (break point).
First, let's assume that we have successfully assembled and linked the code and obtained the executable file. We can then run the program using an emulator or an assembler/debugger like DOSBox or Turbo Debugger.
When the execution reaches the first INT3 instruction, we need to pause the program and examine the content of the stack, registers, and variables.
Content of Stack:
At this point, the stack should contain the pushed values of AX, BX, CX, and DX. Note that the top of the stack is the last element pushed.
Stack:
SP -> | DX | CX | BX | AX |
+----+----+----+----+
Content of Registers:
- AX: Contains the value 1
- BX: Contains the value 2
- CX: Contains the value 3
- DX: Contains the value 4
Content of Variables:
- DATA1: Contains the values 7, 9, 10, 11, 12 (an array of signed words)
- SUM: Contains the value 3
2) Comment out the first INT3. Run the program again.
After commenting out the first INT3 instruction, we can reassemble and rerun the program. At this point, we need to pause the program again to examine the content of the stack, registers, and variables.
Content of Stack:
Since we didn't push any additional values onto the stack after the previous breakpoint, the content of the stack remains the same.
Stack:
SP -> | DX | CX | BX | AX |
+----+----+----+----+
Content of Registers:
The content of the registers remains the same as before.
Content of Variables:
The contents of the variables DATA1 and SUM should also remain the same as before.
Note: The program doesn't have additional breakpoints, so it will continue executing until the end. If you want to examine the content of the stack, registers, and variables at the end of the program, you can pause the execution just before it terminates and inspect the values.
Show the Stack Pointer.
To show the Stack Pointer (SP), we need to check the value stored in the SP register. In the given assembly code, the MOV SP, AX instruction sets the value of AX register to SP. So, to see the Stack Pointer value, we need to look at the content of AX.
The initial value of AX is set to 0460h, which is the address where the stack will start. Since AX is directly assigned to SP, the initial Stack Pointer value is also 0460h.
Therefore, the Stack Pointer (SP) value is 0460h.
is Content of Registers and Variables correct?
Apologies for the confusion. Let's correct the content of registers and variables based on the given assembly code:
Content of Registers:
- AX: Contains the value 0460h
- BX: Contains the value 2
- CX: Contains the value 3
- DX: Contains the value 4
After the PUSH instructions, the content of the stack will be:
Stack:
SP -> | DX | CX | BX | AX |
+----+----+----+----+
Content of Variables:
- DATA1: Contains the values 7, 9, 10, 11, 12 (an array of signed words)
- SUM: Contains the value 3
Please note that the correction has been made based on the provided assembly code, but it's always a good practice to verify it with the actual execution of the program using an assembler or debugger.
is this for part 1) or part 2)
I apologize for the confusion. The corrected content of registers and variables provided is for part 1) of the instruction where we are examining the content of the stack, registers, and variables at the first INT3 breakpoint.
For part 2), as the program continues executing without encountering any further breakpoints, the content of the stack, registers, and variables remains the same as in part 1).
If you have any further questions or need clarification, please let me know.