Removable Media
Dec 24, 2015
Removable Media
Floppy Disk Drives
Almost a dead deal
The Basics
• Media/plastic/media• Spins at 360 rpm• Read/Write heads contact the disk surface –
so don’t pull a floppy while the activity light is on
Formatting
• Electronic map for storing data/files on the disk• Concentric circles – tracks• Slice up tracks to get sectors; each sector holds 512
Bytes of data• Sets up four areas: boot record, File Allocation Table
(FAT), Root Directory and Data Area• Formatting is different for different devices (PCs,
Macs, Sewing Machines, …)
Mac and PC disks
• Mac drives have two motors: spindle and eject/insert
• Spindle motor is variable speed on Macs• Macs can read and write PC disks• PCs can’t read or write Mac disks
Types of Disks
• You can still find Double-sided, Double density (760 Bytes) disks – DD for short
• Most are Double-sided, High density – HD at 1.44 MB
• So much hassle over formatting that they come already formatted now
Installing Floppy Drives
• A: or B: - reserved by Windows for floppy drives
• Connect with 34-pin ribbon cable
Installing, cont.
• Red stripe is Pin 1• Get the connector backwards, drive light will
stay on, but drive won’t work. No harm to system.
• Be careful with power connector – get that upside down and you cook the drive
CMOS
• Should automatically detect drive• Swap Floppy Device setting allows A to B swap
– only if you have two drives• Boot Up Floppy Seek – disable to save two
seconds during POST
Boot Sequence
• Where will I find an OS?• I set CD first, then floppy then hard disk drive• Often have to poke around in CMOS to find
where you set this
Maintenance
• I keep a floppy drive cleaner disk• Too much use, or too little use and drive
heads will need cleaning• Don’t poke around with a Q-Tip
Troubleshooting
• Drive won’t read floppy disk• Take disk to another computer• Try another floppy disk (known good)• Clean the read/write heads• Replace the drive
USB floppy drives
• Popular for laptops• Can’t boot from them – need USB drivers to
load first
Flash Memory Drives
• Thumb drive, Jump Drive, Flash drive• Gaining in popularity daily• Have replaced Zip/floppy drives• Is 32GB still the upper limit? No?
CompactFlash (CF)
• Oldest, most complex and physically largest of memory cards.
• Can also get a microdrive in CF II form factor• About extinct now
SmartMedia
• After CF• Used in digital cameras for a while• Almost extinct now
Secure Digital (SD)
• Newest on the block• Most common format used today• SD and SDIO formats – not interchangeable• Mini and Micro show up in cellular phones
Card Readers
• Can be external to PC or mounted internally (in 3.5” bay)
• 5 to 7 to 9 slots for different media types
CD,DVD and Blu-Ray Media
Optical Drives
Definitions
• CD-ROM – Compact Disk, Read Only Media/Memory; this is how programs come to you
• DVD – Digital Versatile/Video Disk
How it lays out
• This time the data is INSIDE the disk:
Data Location
Label, or not
Laser
1 0
ISO 9660
• Also called: High Sierra for the hotel in Colorado where standard got developed
• Joliet – Microsoft’s extension(s); Mac and Linux support these also.
• Rock Ridge – UNIX file system support• El Torito – Bootable CD media• Apple Extensions – Apple’s HFS file system
CD Speed
• 1x : Original (and still) audio standard: 150,000Bps or 150KBps
• 4x : 600KBps• 24x : The “magic line”– Below this drives and connections were proprietary – and
often to sound card– These drives were single speed – always on
• At and above 24x– Variable speed – spin up, read, spin down– Uniform connection method (ATAPI-6)
To Burn a CD• Second, more powerful laser (10x read)• Two CD-R formats: 72-minute (650 MB) and
80-minute (700 MB)• Burns organic dye to create pits (0’s)• Need burning software below XP • CD-R is write once, read many• CD-RW is write often, read often (can be
erased)• Speeds are <write><re-write><read>;
16x10x40x for mine
UDF
• Universal Data Format, replacement for 9660• Vista supports this but not XP• Supports packet writing• Roxio’s DirectCD and Nero’s InCD allow disk to
feel like a hard/floppy disk
DVD
• Big step up in capacity: 4.37 GB• Smaller pits, more dense than CD• Single-sided or double-sided• Single layer or double layer• You need decoder (MPEG-2) to watch movies
on your PC – most DVD drives ship with them• DVD+R, -R, +RW and –RW
Blu-Ray
• Uses blue laser (405 nm) vs. red (650 nm)• Capacity of 25 GB and multiples• Still on the pricy side of things ($50+)
ISO files
• A complete copy of the contents of an optical disk
• Win 7 will “burn an ISO” i.e. make a disk from the ISO file (not copy the iso to disk)
• Need software for XP and Vista – find free on the Internet
Region Codes
• Attempt to limit distribution/bootlegging • Can only change four times then stuck• Region 0: all regions• Region 1: US and Canada• Region 8: Cruise ships and airlines
Installation
• Master or Slave• Ribbon (data) cable• Power• You can still find SCSI drives• Most optical drives are SATA today
Buffer Underrun
• Fortunately, it is a thing of the past (16x burn rate and slower drives)
• No, you don’t see a spec on the buffer size on the drive’s box
• BURN-Proof seems to be the maiden name for underrun protection
Troubleshooting
• I have had zero luck with trying to clean an optical drive to get it functioning again
• Sometimes it’s a compatibility issue… but rare today
• Replace the drive, they are not that expensive