Revert "Stub serial"

This reverts commit d63c2cbd69.

messages.asm

@@ -21,9 +21,6 @@ mov dh, HEIGHT
 mov dl, WIDTH
 int 0x10
 
-;; Turn on interrupts
-sti
-
 ;; Set cursor to bottom of screen
 mov dh, HEIGHT
 mov dl, 0x00
@@ -31,33 +28,10 @@ mov bh, 0x00
 mov ah, 0x02
 int 0x10
 
-;; Start serial connection
-mov ah, 0
-mov al, 0b11100011
-mov dx, 0
-int 0x14
-
 .loop:
-        ;; Print a '.' to debug
-        mov ah, 0x01
-        mov al, '.'
-        mov dx, 0
-        int 0x14
-
-
-        ;; Check status of COM1
-        mov ah, 0x03
-        mov dx, 0
-        int 0x14
-
-        ;; If not ok, wait
-        and ah, 0x01
-        jz .loop
-
-        ;; If ok, start reading character
-        mov ah, 0x02
-        mov dx, 0
-        int 0x14
+        ;; Read character
+        mov ah, 0x00
+        int 0x16
 
         cmp al, 0x0d ; newline
         je .newline