MPLab3 Sorting

; Program to sort an array

1. Define the model and architecture for the assembly code

.model SMALL
.stack 100H
.386

2. Define your data in the data section ( here you can define various data items: variables, constants, strings, arrays)

.data
	ARRAY dw 20 DUP (?)     ;The DUP directive is used to specify the number of times the question mark (?) is duplicated (20 times)
	DATA1 dw 0000H
	NUMB dw 0000H
	msg db 10,13,"Enter the size of the array: $"
	msg2 db 10,13,"Enter the elements of array: $"
	msg3 db 10,13,"The sorted array is: $"

3. 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)

.code
.startup
	
        ; print Enter the size of the array message
        MOV AH, 09H
	MOV DX, OFFSET msg  	
	INT 21H

	;Read the size of the array	
	MOV AH, 01H
	INT 21H

	;The binary equivalent(8-bits) of the ASCII code for the entered character is stored in AL

	SUB AL,30H     ; convert the character digit ('0' to '9') into corresponding numeric value( 0 to 9)   
	MOV AH,0     
	MOV CX, AX     ; This instruction loads the CX with the size of array
	
        MOV DATA1, AX     ; The size is also stored in DATA1
		
	; print Enter the elements of Array message	  
	MOV AH, 09H
	MOV DX, OFFSET msg2
        INT 21H
        
       '''; Read the individual elements, convert them from ASCII characters to integers, and stores them in the ARRAY.''' 
        
        MOV AH, 0      
	MOV SI, 0     ; SI is initialized to 0, which means it's pointing to the beginning of array
	
        MOV BX, OFFSET ARRAY     ; Loads the offset address of the label ARRAY into the BX register.

        L1: 	MOV DL, 0AH     ; Move the newline character (line feed) into DL to jump onto next line		
                MOV AH, 02H
		INT 21H
		
                 ; input element of the array
                MOV DX, SI     
		MOV AH, 01H
		INT 21H		
              
                SUB AL,30H     ;  convert the character digit ('0' to '9') into corresponding numeric value( 0 to 9) 
		
                MOV SI, DX
		MOV [BX + SI], AX     ; stores the value in AX into a memory location specified by the contents of the BX and SI registers. 		
                INC SI     ; increment the value of SI register by 1
		LOOP L1

       '''; Sorting'''      
        MOV CX, DATA1     ; CX is loaded with the number of elements in the array.
	MOV BX, OFFSET ARRAY     ; BX is set to point to the beginning of the ARRAY
	MOV DI,CX     ; DI is loaded with the number of elements in the array
	
        ; outer loop
        L2: 	; MOV CX, DATA1      
		MOV NUMB, CX     ; Change1,  NUMB is loaded with the current number of elements (CX)
		DEC NUMB     ; Change2, NUMB is decremented by 1, effectively reducing it by one element for each pass of the outer loop.
		MOV CX, NUMB     ; change3,  CX is updated to hold the current number of elements after decrementing.
		MOV SI, 0     ; SI is initialized to zero, which serves as an offset within the array
	
        ;  inner loop
        L3: 	MOV AL, [BX + SI]     ; AL is loaded with the current element in the array
		CMP [BX + SI + 1],AL     ; Compares the current element (AL) with the next element in the array
		JL L4     ; If the next element is less than the current element, it swaps them. Otherwise, it continues to the next element.
		XCHG AL,[BX + SI + 1]    ; Swaps the values of the current element and the next element.
		MOV [BX + SI],AL    ; Moves the updated value back into the current element's position in the array.
	L4: 	INC SI     ;  Increments SI to move to the next element in the array.
		LOOP L3     ; Repeats the inner loop L3 for the remaining elements in the array (according to the updated CX value).
		
	DEC DI     ; After the inner loop is complete, the outer loop continues until all elements are compared and sorted. DI is decremented, and the process continues for the remaining elements.
	JNZ L2     ; checks the value of the DI register. If DI is not equal to zero, the program jumps back to the label L2.

        '''; Displays the sorted array'''
        MOV CX, DATA1
	MOV SI, 0
	MOV BX, OFFSET ARRAY
	
        MOV AH,09
	MOV DX, OFFSET msg3
	INT 21H
	
        L5: 	MOV DL, 0AH ; jump onto next line
		MOV AH, 02H
		INT 21H

		MOV DX, [BX + SI]
		INC SI
		ADD DL, 30H
		
                MOV AH, 02
		INT 21H
	
         	LOOP L5        
	
	; exit from the program	
	MOV AH, 4CH
        INT 21H

END