各位大哥看下有什么错误

方案一
assume cs:codesg
codesg segment
start:
mov ax,0b800h
mov ds,ax
xor si,si
mov ax,0241h
mov [si],ax
mov ah,1
int 21h
mov ax,4c00h
int 21h
codesg ends
end start

方案二
code segment
assume cs:code,ds:code
start:
mov ax,3
int 10h
mov ax, 0B800h
mov ds, ax
mov ax, 241h
mov ds:0, ax
mov ah, 0
int 16h
mov ah, 4Ch
int 21h
code ends
end start

悬赏太少了

assume cs:codesg
end