Floppy Drives

1
Lecture 2.3.10

• Floppy Drives

2
Floppy Disks

• A small platter of flexible plastic with iron
  oxide coating
• Stores information magnetically

3
Disk Size

• The original disks were 12 in diameter and could
  be damaged easily
• IBM came out with 8 disks that had protective
  shells on them
• 5-1/4 disk where an improvement in the design
• Newest floppy disks are 3-1/2 and have a hard
  shell

4
Floppy Capacity

• Designations (5-1/4)
• DSDD Double Sided, Double Density (360KB)
• DSHD - Double Sided, High Density (1.2MB)
• Designations (3-1/2)
• DSDD Double Sided, Double Density (720KB)
• DSHD - Double Sided, High Density (1.44MB)
• DSEHD - Double Sided, Extra High Density
  (2.88MB)

5
Floppy Drive Connections

• All floppy drive cables allow you to connect 2
  drives to each system
• Designated by A and B
• The position on the cable determines whether it
  is A or B
• Drive type set in CMOS
• Always connect pin 1 on the cable to pin 1 on the
  drive

6
Cable Positions

• Uses a Ribbon Type cable with 34 pins
• All drives after the twist are A (3)
• Drives in the middle are B (2)
• The end plugs into the motherboard (1)

7
Power Connectors

• 5-1/4 drives use a Molex connector
• 3-1/2 drives use a mini Molex connector
• Can be inserted one way only