.model small .stack 100h .data db ' test $' .code mov ax, @data mov ds, ax mov si, 0 mov cx, 0 myloop: cmp a[si], '$' je final cmp a[si], ' ' inc si je count jmp myloop count: inc cx jmp myloop final: mov dx, cx mov ah, 9 int 21h end
you override flags "is blank" comparison subsequent "inc si"
.model small .stack 100h .data db ' test $' .code mov ax, @data mov ds, ax mov si, 0 mov cx, 0 myloop: cmp a[si], '$' je final cmp a[si], ' ' jne do_not_count ; skip count if it's not blank count: inc cx ; blank, count do_not_count: inc si jmp myloop final: ;mov dx, cx ; not print cx ;mov ah, 9 ;int 21h mov dl, cl ; workaround: works cx < 10 add dl, '0' mov ah, 2 int 21h end 