i apologies if this question seems to be in wrong section, but i am new to kernel as well as osdev.org!!!

I am writing a Kernel as my final Year project in Engineering. I am referring Bran's kernel development tutorial (only).
I am doubted about can i use a hard disk with my kernel(Bran's says no need!!).
My project guide wants me to include a game & text editor which can save a file .txt onto the hard disk, and later retrieve it,
please lemma know, if it is possible.
i will really be thankful for a fast reply, as my days are short. (i mean, project duration!!)