A disk is a bunch of bits (2023)

Introduction Have you ever heard someone say that a disk or memory is a “bunch of bits”? I’m not sure about this idea’s origin, but it’s a pretty good idea. It reduces the mystery of computers. For example, it rules out the theory that inside of my computer is a very flat elf. No, inside are bits, encoded on electrical components. Getting close and personal with bits Yet, computers are still pretty mysterious. What are these bits? What do they mean? Can we play with them, parse them, make sense of them? In this post, I will show you that, yes, absolutely we can! For your entertainment, I am going to stick my hand into my computer, pull up a bunch of bits, and we will examine and make sense of them. What bits, exactly, should we explore? For this exercise, let’s pick apart how a disk-backed file is represented on disk. Say we have a file called /data/example.txt : $ cat /data/example.txt Hello, world! Here’s one big question: where does “Hello, world!” live? Also, you may kno ... Read full article.