mov     ax,00A9  ;Find the square root of 169

;
;Written for the Magic Assembler
;AX=Integer to find the square root of
;CX=Integer square root of AX
;

@squareroot
        xor     cx,cx    ;Clear the result register
        mov     bx,4000
@1      cmp     bx,0
        je      @3
        mov     dx,cx
        add     dx,bx
        shr     cx,1
        cmp     dx,ax
        ja      @2
        sub     ax,dx
        add     cx,bx
@2      shr     bx,1
        shr     bx,1
        jmp     @1
@3

;Quickie result display routine
        cmp     cx,0     ;Finished?
        je      @4       ;If so, then end.
        mov     ax,cx    ;Move remaining digits into AX
        and     ax,000f  ;Mask all except the first digit
        shl     ax,1     ;Double the value to account for '$' characters

        shr     cx,1     ;Shift right eight
        shr     cx,1     ;times to remove the
        shr     cx,1     ;current digit from
        shr     cx,1     ;the next print
        shr     cx,1     ;cycle and prep next
        shr     cx,1     ;digit for display
        shr     cx,1     ;or if finished,
        shr     cx,1     ;zero the register.

        mov     dx,offset(numbers)
        add     dx,ax    ;Point to the appropriate number
        mov     ah,09
        int     21       ;Print digit
        jmp     @3       ;Repeat cycle
@4      mov     ah,4c
        int     21       ;End

numbers db      '0$1$2$3$4$5$6$7$8$9$A$B$C$D$E$F$'