Storage Devices

Storage Devices

1. Punch cards

   • Punch cards, also known as Hollerith cards and IBM cards are paper cards containing several punched or perforated holes that were punched by hand or machine to represent data. These cards allowed companies to store and access information by entering the card into the computer.
   • this was man's first step in technology.
   • Disadvantages
     • Density of data. You can't store very much data on a punch card or paper tape.
     • The inability to perform random seeks of the data.
     • the inability to erase and reuse the media.
     • 5 machines needed to be used to read punch cards.
   • Advantages
     • Data longevity. Magnetic and optical media that we use now has a fairly short lifespan, shorter than most people would assume.
     • Relatively low cost.
     • People, as well as machines, can read the card data.
     • Can be used as a turnaround document
   • Made in 1890

2. Floppy disk

   • A floppy disk, also known as a floppy, diskette, or simply disk, is a type of disk storage composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic enclosure lined with fabric that removes dust particles. Floppy disks are read and written by a floppy disk drive.
   • Disadvantages
     • It is easily destroyed by dust and dirt.
     • Its storage capacity is limited.
     • It is difficult to handle.
     • It can transform a virus from one machine to another.
     • Nowadays computers do not have floppy disk drives.
   • Advantages
     • Relatively small
       • Smaller than CDs!
     • Portable (5.3 inches)
     • Don't need packaging, as already protected by plastic casing

3. Compact Disk (CD)

   • Compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony and released in 1982. The format was originally developed to store and play only sound recordings (CD-DA) but was later adapted for storage of data (CD-ROM).
   • Advantages
     • Security.
     • Low cost, more sales.
     • Portable.
   • Disadvantages
     • Easy to break and scratch, must be kept in a container if you want to keep it safe.
     • If scrachted sometimes not able to use, meaning you have to get another.

4. Solid state VS. Magnetic VS. Optical

   • Solid state
     • What is solid state?
       • It is a device with no moving parts.
         • Is that good or bad?
           • Good
             • It has a chance it won't break as easily.
           • Bad
             • It could break.
   • Magnetic
     • what is magnetic?
       • a storage device with moving parts.
         • Is that good or bad?
           • Good
             • it is faster
           • Bad
             • It can get clogged and broken if dropped.
   • Optical
     • what is optical?
       • Any device that has a light source
         • good
           • Useable on discs.
         • bad
           • If its too bright you can't see the light.
   • Which one is the best?