1. consider the following program. interpret the program line by line. Get an idea what the program.
TOS EQU 0FEFEH
CPU 8086
ORG 0400H
SECTION CODE:
MAIN:
MOV SP, TOS
CALL INITIALIZATION
MOV BX, PATTERN
MOV AL, [BX]
JMP $
INITIALIZATION:
MOV WORD[03FCH], COUNTERISR
MOV WORD[03FCH], 0
MOV AX, 0
STI
RET
COUNTERISR:
OUT 0, AL
IRET
SECTION DATA:
PATTERN DB 255, 128, 170, 15, 240
Do the following, don't run the program yet on the 8086 trainer kit.
Part a:
a) by following the program as above, determine what would be the pattern that should be displayed on the LEDs.
Answer:
b) change the special instruction in the above [BX+1]. Determine what would be the pattern that should be displayed on the LEDs.
Answer:
c) change the special instruction in the above [BX+2]. Determine what would be the pattern that should be displayed on the LEDs.
Answer:
d) change the special instruction in the above [BX+3]. Determine what would be the pattern that should be displayed on the LEDs.
Answer:
e) change the special instruction in the above [BX+4]. Determine what would be the pattern that should be displayed on the LEDs.
Answer:
a) By following the program, the pattern that should be displayed on the LEDs is 255, 128, 170, 15, 240.
b) If the special instruction [BX+1] is changed, it would affect the pattern. However, since the program does not mention what the new value should be, it is not possible to determine the new pattern without that information.
c) Similar to part b), without knowing the new value for [BX+2], it is not possible to determine the new pattern.
d) Again, without knowing the new value for [BX+3], it is not possible to determine the new pattern.
e) Without knowing the new value for [BX+4], it is not possible to determine the new pattern.
what is the answer for a) to e)
Apologies for the confusion. Let's analyze the program to determine the patterns for each part:
a) The pattern that should be displayed on the LEDs is 255, 128, 170, 15, 240.
b) If the special instruction in [BX+1] is changed, it would affect the pattern. However, since the program does not specify any change, the pattern would remain the same as in part a) - 255, 128, 170, 15, 240.
c) Similar to part b), without any specific change to [BX+2], the pattern would remain the same - 255, 128, 170, 15, 240.
d) With the special instruction changed in [BX+3], the new pattern that should be displayed on the LEDs depends on the new value. Unfortunately, as the program does not provide any information about the new value, it is not possible to determine the new pattern without that information.
e) Similarly, without knowing the new value for [BX+4], it is not possible to determine the new pattern.
a) By following the program, the pattern that should be displayed on the LEDs is: 255, 128, 170, 15, 240.
b) If the special instruction [BX+1] is changed, it will modify the second element of the PATTERN array. To determine the new pattern, you would need to know what value is inserted at that particular memory location.
c) Similarly, if the special instruction [BX+2] is changed, it will modify the third element of the PATTERN array. Knowing the new value inserted at the corresponding memory location would determine the new pattern.
d) Changing the special instruction [BX+3] would modify the fourth element of the PATTERN array. Again, the new pattern would depend on the value inserted at that memory location.
e) Lastly, changing the special instruction [BX+4] would try to modify the fifth element of the PATTERN array. However, since the PATTERN array only has four elements (0 to 3), an error or unexpected behavior might occur.