Show the contents of each register and or memory location used after each instruction.
MOV BH,33 BH=33
MOV [0500],BH BH=33, [0500]=33
MOV CL,66 CL=66
MOV [050],CL CL=66, [050]=66
MOV SI,0500 SI=0500
MOV BX,7643 BX=7643
ADD [SI],BX SI=0500, [0500]=76 ,[501]=DC
INT 20
To determine the contents of each register and memory location after each instruction, we can go through the program step by step:
1. MOV BH,33: This instruction moves the value 33 into the BH register. Therefore, after this instruction, the contents of BH will be 33.
2. MOV [0500],BH: This instruction moves the value in the BH register (which is 33) into the memory location at address 0500. After this instruction, both BH and the memory location [0500] will contain the value 33.
3. MOV CL,66: This instruction moves the value 66 into the CL register. Therefore, after this instruction, the contents of CL will be 66.
4. MOV [050],CL: This instruction moves the value in the CL register (which is 66) into the memory location at address 050. After this instruction, both CL and the memory location [050] will contain the value 66.
5. MOV SI,0500: This instruction moves the value 0500 into the SI register. Therefore, after this instruction, the contents of SI will be 0500.
6. MOV BX,7643: This instruction moves the value 7643 into the BX register. Therefore, after this instruction, the contents of BX will be 7643.
7. ADD [SI],BX: This instruction adds the value in the BX register (which is 7643) to the memory location at the address stored in the SI register (which is 0500). The value at the memory location [0500] before the addition is 33. After the addition, the value at the memory location [0500] will be 33 + 7643 = 7676. Therefore, after this instruction, SI will still be 0500, and the memory location [0500] will contain the value 7676.
8. INT 20: This instruction generates a software interrupt, which typically exits the program. The specific effects of the interrupt depend on the operating system or environment in which the program is running. Therefore, the contents of the registers and memory locations after this instruction will depend on the interrupt handler and the subsequent execution.
Please note that the above explanations are assuming an x86 assembly-like language. The specific register and memory location names may vary depending on the architecture and assembly language being used.