1. Lecture
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”): Designations (3-1/2”)
DS:DD – Double Sided, Double Density (360KB)
DS:HD - Double Sided, High Density (1.2MB)
Designations (3-1/2”)
DS:DD – Double Sided, Double Density (720KB)
DS:HD - Double Sided, High Density (1.44MB)
DS:EHD - 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