diff --git a/04-bootsector-stack/boot_sect_stack.asm b/04-bootsector-stack/boot_sect_stack.asm
index 37399f0..5bff2ab 100644
--- a/04-bootsector-stack/boot_sect_stack.asm
+++ b/04-bootsector-stack/boot_sect_stack.asm
@@ -1,7 +1,7 @@
-mov ah, 0x0e
+mov ah, 0x0e ; tty mode
 
 mov bp, 0x8000 ; this is an address far away from 0x7c00 so that we don't get overwritten
-mov sp, bp
+mov sp, bp ; if the stack is empty then sp points to bp
 
 push 'A'
 push 'B'