diff --git a/arch_install.md b/arch_install.md
index 4b277a8..826cbf8 100644
--- a/arch_install.md
+++ b/arch_install.md
@@ -22,6 +22,13 @@ Verify that the [system clock is up to date][8].
 
     $ timedatectl set-ntp true
 
+(bios mode)
+
+   $ parted -s /dev/sda mklabel msdos
+   $ parted -s /dev/sda mkpart primary  1MiB 513MiB
+   $ parted -s /dev/sda mkpart primary 1024MiB 100%
+   $ mkfs.ext2 /dev/sda1
+   $ mkfs.ext4 /dev/sda2
 
 (UEFI mode) Create partitions for EFI, boot, and root.
 
@@ -92,7 +99,7 @@ Set your mkinitcpio.
 Configure GRUB.
 
     # BIOS mode 
-    $ grub-install /dev/sdat
+    $ grub-install /dev/sda
     $ grub-mkconfig -o /boot/grub/grub.cfg