Hard Disk Drives
A hard disk drive (HDD) is a device that stores digital information. It does so by methods called reading and writing, other wise known as retrieving and storing data.
The very first commerical HDD was presented by International Business Machines (IBM) in 1956. The product consisted of a housing unit called the IBM 350 and the physical disks that would be known as the hard drive, called IBM 305 RAMAC. The IBM 350 stored 50 of the 305 disks which would be spinning while functioning. Each housing unit weighed about one ton and contained about 5 million characters (625,000 bytes).
1 character = 1 bit
8 bits = 1 byte
1 MB = 1,048,576 bytes
So to give a perspective of what the IBM 305 was capable with, an average picture taken by a smartphone is about 3 MB. The higher quality the picture, the higher memory space it would take up. Given that 3 MB is the average size of a modern picture, we would need about 4 to 5 disks.
It cost about $10,000 a MB. The disks rotated at 1,200 RPM, which determines the speed of data storing and retrieving. It accessed data at 100,000 bits a second.
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In 1975 the IBM 62GV / STC 8800 Super Disk was popularized and was the first HDD to use a rotary actuator which is what is used in modern production of current HDDs. It held about 5 MB with subsequent models of 10 MB to 14 MB, all with 2964 RPM.
HDD models by IBM used the rotary actuator until the 1990s and was replaced with newer technology for the rotary arms.
IBM 305 disk held by Bill Worthington standing next to a part of the IBM housing unit. (BOT)
IBM 0665 model using the rotary actuator. (TOP)
The IBM Personal Computer XT was introduced in 1983 and featured an internal 10 MB hard drive. Soon other PC's followed suit as it became a standard to feature internal memory.
In 1984 the first Macintosh was introduced however it did not feature an internal memory but did feature 128k of RAM. RAM is Random Accessing Memory and the data does not become saved as possible with HDDs.
IBM Personal Computer XT. (TOP)
First Macintosh created and designed by Apple Inc. (BOT)
After the late 1990s, we begin seeing more personal computers in households. They were called desktops and featured a housing system that held all the components that made the system functional and a separate system called the monitor which is other wise known as a screen that displays the digital information. Most desktops featured hard drives that were 3.5 inches long and was and still is the standard size for desktops to date. The only difference is the amount of digital information available to store and the speed of accessing the data.
My first desktop was custom build (not built by manufacturing company) and featured a hard drive that had 256 GB (gigabyte) of memory. It had a speed of about 3200 RPM. It was also standard in all desktops at the time than ran Windows XP.
From 2008 onwards, the introduction of higher GB of memory space was introduced and more commonly used. The physical size of the devices also decreased to fit into laptops. They were and still are 2.5 inches in length. In 2008, many of the laptop HDDs held about 450 GB to 750 GB of memory. In recent years we have seen the use of 1 TB (terabyte) memory in modern laptops and desktops and with speeds of 3 GB/s transfer rate of accessing data. The disks spun at rates of 5400 RPM or 7200 RPM depending on the model and size of the HDD.
The use of larger memory space allowed for more applications to be used such as running photoshop, music players, playing video, games, etc. As memory in the devices increased, the product became more affordable. One 750 GB HDD at 5400 RPM with 3 GB/s data transfer rate can be bought for about $60.
Today, in 2014, we see laptops that hold 2.5" HDD that can go up to up to a little over 1 TB of memory and desktops that can hold over 3 TB of memory. The best part is that quality does not have to be sacrificed while increasing a larger memory size HDD as seen in gaming laptops and desktops.
ASUS ROG Gaming Laptop 1.5 TB HDD. (TOP)
Alienware Aurora Gaming Desktop 2 TB HDD. (TOP)
Click to see my recommended HDDs.
IBM 350 Housing Unit for the IBM 305 RAMAC disks. (TOP)
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