Introduction

The hard drive of a computer is where all your important information is stored. Photos, videos, documents, they’re all stored on the hard drive. Without data storage in your own PC, computers just wouldn’t be so useful for the average person. And even the average person’s demand for storage has grown exponentially. Whereas we were once content with 16MB drives, everyone’s now after their very own terabyte of space. And hard drive manufacturers deliver. Hard drive technology is one of the most impressive areas of growth in the computing industry.

A hard drive, the non-volatile memory of a computer, is nothing but a framework of magnetic disks, known as platters, used for storing or recording information. As soon as you save data on your computer, the information ultimately transfers to your hard drive. So what is the difference between RAM (random access memory) and hard drive? It’s pretty simple. Before saving data, for example when you’re typing in Word but you haven’t saved the file yet, the data is stored in RAM but after saving, the data automatically transfers to the hard drive. Digitally encoded data is saved on rapidly revolving platters, each with a magnetic surface, and therefore it remains intact even after turning off the computer.

Hard Drive (Source: techadmire.com )

It’s really pretty interesting. A hard drive reads and writes data to the platters in the drive in a series of ones and zeros (binary), at the same time transmitting information back and forth between the CPU and the drive. The process is more complex than that, but that is a short version of how hard drives work.

The first hard drive was invented by IBM engineers working under Rey Johnson at IBM in San Jose, California, between 1952 and 1954. A typical hard drive for a desktop computer today holds somewhere between 120 and 500GB of digital data, rotates at 7200 RPM and transfers at 1GB/s.

Before Hard Drives

Before hard drives, paper was used for storing programs and data by punching holes in it. They were called punch cards, but they were very inconvenient to use as you have to write entire programs on cards by punching holes on the paper. Then came magnetic tapes or magnetic drums which have a linear method of arranging data in long parallel tracks that span the length of the tape. But they don’t allow for random access of data – a bit like having to fast forward to a spot on a cassette tape instead of being able to jump ahead to a track on a CD.

 Magnetic Tapes (Source: indigoplc.com)