Part A) Explain what these programs do?
Program 1:
MOV AL, data1
MOV BL, data2
CMP AL,BL
JS negative
PUTC 'M'
JMP stop
negative: PUTC 'L'
stop: int 3
Program 2:
MOV AL, 0H
MOV CX, 000AH
Again: ADD AL, 2H
DEC CX
JNZ Again
int 3
Program 1 takes two values (data1 and data2), compares them using the CMP instruction and then performs a conditional jump to either the "negative" label or the "stop" label depending on the result of the comparison. If data1 is less than data2, it will jump to the "negative" label and output the character 'L' using the PUTC instruction. If data1 is not less than data2, it will jump to the "stop" label and output the character 'M' using the PUTC instruction. Finally, it will execute the "int 3" instruction which interrupts the program and returns control to the operating system.
Program 2 initializes the AL register to 0 and the CX register to the value 10 (000AH in hexadecimal). It then enters a loop that adds the value 2 (in hex) to the AL register and decrements the CX register by 1 each time the loop executes. This loop will continue until CX is no longer zero (JNZ instruction). Once the loop completes, it will execute the "int 3" instruction which interrupts the program and returns control to the operating system. The end result of this program is that the value in AL will be 20 (14H in hexadecimal) since it adds 2 to AL 10 times.
Program 1:
This program performs the following steps:
1. Move the content of the memory location data1 into the AL register.
2. Move the content of the memory location data2 into the BL register.
3. Compare the content of the AL register with the content of the BL register.
4. If the comparison results in a signed jump (JS) condition, execute the following steps:
a. Print the character 'M' to the output.
5. Jump to the stop label, regardless of the outcome of the comparison.
6. If the comparison results in a negative branch (negative label), execute the following steps:
a. Print the character 'L' to the output.
7. Execute the int 3 instruction, which is typically used for debugging purposes.
Program 2:
This program performs the following steps:
1. Set the content of the AL register to 0H (hexadecimal).
2. Set the content of the CX register to 000AH (10 in decimal).
3. Start a loop labeled as "Again":
a. Add the value 2H (hexadecimal) to the content of the AL register.
b. Decrement the content of the CX register by 1.
c. If the result of the decrement is not zero (JNZ), jump back to the beginning of the loop.
4. Execute the int 3 instruction, which is typically used for debugging purposes.