Question

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:

Answer 1

what is the answer for a) to e)

Answer 2

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.

Answer 3

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.