Storage devices usually include CD-ROM or DVD drive, hard disk drive and flash drive.
USB DRIVES
Data is stored in flash memory joined with a USB (Universal Serial Bus) interface. It is removable and rewritable. It is small to fit in a pocket with weight less than 30 g and can store upto 256 GB. It is more durable and reliable due to no moving parts and supported by operating systems like Linux, Mac OS X, and Windows. They are also called USB flash drives or pen drives. It draws power from the computer via USB connection and follow USB 2.0 and upcoming USB 3.0 standard.
CD-ROM, CD-R and CD-RW Drives
It is disc of polycarbonate plastic, with a reflective surface. Bootable CD follow ISO 9660 standard for file system. They have a speed factor in ‘x’ where 1x is data transfer rate of 150 KB/s and maximum 52x is achieved. It has capacity of 700 MB and DVD up to 4.3 GB and upcoming Blue ray has up to 50GB. It connects to the computer by an IDE (ATA), SCSI or SATA for internal or USB for external connection to chassis.
HDD Basics
It is used for permanent storage and quick data access and is usually inside the chassis but external drives are also available It has one or more circular platters or disks, put together above each other to spin together, inside the sealed enclosure which stores data. Each disk surface is divided into concentric circles, called tracks and each track is further divided into 512-byte segments called sectors. Hard disk needs to be partitioned before use. Disk partitioning is dividing a hard disk drive into multiple logical storage units called as partitions, to treat one physical disk drive as if it were multiple disks.
HDD Troubleshooting
Hard disk problems usually show up at POST, unless there is physical damage to specific area of the disk. If an error message “Invalid drive or drive specification” comes then it may be due to loss of boot partition or bad sectors. Follow the following tips for solution
- Remove and reattach drive cables.
- Set CMOS to default settings to check BIOS setup for errors
- Try booting from bootable DVD or CD.
- Use a boot CD with hard drive diagnostic software to check and remove errors.
- Reconnect or swap the drive data cable, disk drive and disk connector on motherboard.
