Display strings in the video memory (call subroutine implementation)

[Html] assume cs: codesg, ds: datasg segment db 'I love China! ', 0 datasg ends codesg segment start: mov ax, datasg mov ds, ax mov dl, 12; row number mov dh, 20 to be displayed; call show mov ax, 4c00h int 21 h, the column number to be displayed. In the display string, convert the decimal number to the corresponding ascii code for display. Show: mov ax, 0b800h mov es, ax; mov di, dl * 160 + dh * 2; transmit the destination to di; mov al, 160 mov ax, 160 mul dl mov di, ax mov ax, 2 mul dh add di, ax mov si, 0 mov ch, 0 s1: mov al, ds: [si] mov cl, al jcxz over mov ah, 2 mov es: [di], ax inc si add di, 2 jmp s1 over: ret codesg ends end start note: 1. in show, the jmp label is used to simulate the loop, because the length of the string to be displayed is unknown in advance. Therefore, print is ended Based on 0 at the end.