Blog: Helping Material of Assembly Language

Amended code for Decending order
;sorting a list of ten numbers using bubble sort
[org 0x0100]
jmp start

data: dw -10, -30, -25, 50, 15, 20, 35, 40, 45, 0
swap: db 0

start: mov bx, 0 ; initialize array index to zero
mov byte [swap], 0 ; rest swap flag to no swaps

loop1: mov ax, [data+bx] ; load number in ax
cmp [data+bx+2], ax ; compare with next number
jge noswap ; no swap if already in order

mov dx, [data+bx+2] ; load second element in dx
mov [data+bx+2], ax ; store first number in second
mov [data+bx], dx ; store second number in first
mov byte [swap], 1 ; flag that a swap has been done

noswap: add bx, 2 ; advance bx to next index
cmp bx, 18 ; are we at last index
jne loop1 ; if not compare next two

cmp byte [swap], 1 ; check if a swap has been done
je start ; if yes make another pass

mov ax, 0x4c00 ; terminate program
int 0x21