MPLab1 Addition - Revision history

Mkwiki at 02:10, 19 September 2023

2023-09-19T02:10:57Z

2023-09-19T01:52:50Z

32-bit Binary Addition Step by Step

2023-09-19T01:50:34Z

32-bit Binary Addition Step by Step

2023-09-19T01:47:05Z

32-bit Binary Addition Step by Step

2023-09-19T01:44:35Z

32-bit Binary Addition Step by Step

2023-09-19T01:44:12Z

32-bit Binary Addition Step by Step

2023-09-19T01:43:23Z

32-bit Binary Addition Step by Step

2023-09-19T01:42:19Z

32-bit Binary Addition Step by Step

2023-09-19T01:42:07Z

32-bit Binary Addition Step by Step

2023-09-19T01:41:47Z

32-bit Binary Addition Step by Step

@@ Line 34: / Line 34: @@
 </pre>
 <pre>
-AGAIN: MOV AH, 01           ; Read a character from the input device using DOS interrupt 21h (AH=01h).  AGAIN for looping.
+AGAIN: MOV AH, 01     ; Read a character from the input device using DOS interrupt 21h (AH=01h).  AGAIN is label for loop.
 INT 21H
-CMP AL, 'A'
+CMP AL, 'A'                   ; Check if the character is greater than or equal to 'A'
-JGE P1
+JGE P1                          ; If greater than 'A', jump to P1
-SUB AL,30H
+SUB AL,30H                  ; subtract 30H to convert it to a decimal digit.
 JMP P4
-P1: SUB AL, 37H
+P1: SUB AL, 37H          ; subtract 37H to convert it to a decimal digit.
-P4: SHL EBX, 4
+P4: SHL EBX, 4            ; Shift the value in EBX left by 4 bits
 MOV AH,00
 ADD EBX, EAX
 LOOP AGAIN
 MOV data1, EBX
 </pre>

@@ Line 34: / Line 34: @@
 </pre>
 <pre>
-AGAIN: MOV AH, 01
+AGAIN: MOV AH, 01           ; Read a character from the input device using DOS interrupt 21h (AH=01h).  AGAIN for looping.
 INT 21H
 CMP AL, 'A'

@@ Line 29: / Line 29: @@
 MOV DX,OFFSET num1
 INT 21H
 </pre>

@@ Line 22: / Line 22: @@
 </pre>
 <pre>
-MOV EBX, 00000000
+MOV EBX, 00000000        ; Initialize EBX to 0; EBX will be used to store the sum.
 </pre>
 <pre>
 MOV AH,09
-MOV DX,OFFSET msg
+MOV DX,OFFSET num1
 INT 21H
 </pre>

@@ Line 18: / Line 18: @@
 . Define your instruction in the code section (here you write the assembly instructions that perform computations, control program flow, and interact with data variables and memory)
 <pre>
-.code                           ; .code directive indicates the beginning of code section
+.code        ; .code directive indicates the beginning of code section
-.startup                        ;  the entry point of the program
+.startup     ;  the entry point of the program
 </pre>
 <pre>

@@ Line 4: / Line 4: @@
 .model small
 .stack 100H
-.386                           ; This specifies that the program will use instructions of the 80386 processor (32-bit instructions).
+.386          ; This specifies that the program will use instructions of the 80386 processor (32-bit instructions).
 </pre>
 . Define your data in the data section ( here you can define various data items: '''variables, constants, strings, arrays''')
 <pre>
-.data                           ; .data directive indicates the beginning of data section
+.data          ; .data directive indicates the beginning of data section
-data1 dd 00H                    ; declares a double-world variable and initializes it to 0.
+data1 dd 00H          ; declares a double-world variable and initializes it to 0.
 num1 db 10,13,"Enter the first number: $"
 num2 db 10,13,"Enter the second number: $"