Add duration of note

messages.asm

@@ -70,14 +70,15 @@ mov sp, 0x2000
         jmp .loop
 
 .beep:
+        call    .readduration
+        mov     ah, 0
+        push    ax
         mov     al, 182         ; Prepare the speaker for the
         out     43h, al         ;  note.
         call    .readbyte
         mov     ah, 0
         sal     ax, 5  ; multiply by 32
         add     ax, 1140
-        ;mov     ax, 4560        ; Frequency number (in decimal)
-        ;                        ;  for middle C.
         out     42h, al         ; Output low byte.
         mov     al, ah          ; Output high byte.
         out     42h, al
@@ -85,7 +86,14 @@ mov sp, 0x2000
                                 ;  port 61h).
         or      al, 00000011b   ; Set bits 1 and 0.
         out     61h, al         ; Send new value.
-        mov     bx, 50000       ; Pause for duration of note.
+        ;; mov     bx, 50000       ; Pause for duration of note.
+        pop bx
+        push ax
+        mov ax, 3125
+        mul      bx
+        mov bx, ax
+        pop ax
+
 .pause1:
         mov     cx, 65535
 .pause2:
@@ -161,6 +169,14 @@ mov sp, 0x2000
         or al, bl
         ret
 
+.readduration:
+        ;; Read duration (0-16 supported)
+        mov ah, 0x00
+        int 0x16
+        ;; Read character is in al
+        sub al, 'a'
+        ret
+
 halt:	hlt
 
 color_mode: db 0x02