Floppy & Removable Media Storage

3.5" Floppy

• Floppy Disk Drive Help (not bad)
• Some floppy drives don't like recessed write enable holes, and so keep the floppy read-only. You can fix this by putting a piece of paper, such as a post-it note over the write notch when trying to write. This could be due to a bad sensor, or if optical, perhaps a poor contrast or reflectivity combination of the floppy case versus the write-enable notch cover.
• 720 K
• 1440 K HD disks.
• 2880 K
• 12xx K Mode-3 used in Japan. Formatted with same capacity 1.2M 5" floppy.

5" Floppy

• Smaller earlier formats, such as the Apple and CPM and TRS-80 use.
• Index hole in envelope & floppy to detect sector 0.
• Hard sectored versus soft sectored: A index hole for each sector, versus one hole per revolution.
• Must cover (not uncover) write-protect notch. Watch out with some drives - they use a mechanical detector, so a squished tab may still allow writing.
• 160K SS
• 180K SS
• 320K DS
• 360K DS
• 1.2M DS

Zip

• 100 MB
• 250 MB
• 750 MB
• Battery Powered
• USB Powered
• External Powered
• The USB Zip drives were made both with and without external power connectors.
• Watch out for the USB-only powered drives. They can act unreliably with some filesystem formats. If an ineffecient filesystem is used (such as MS-DOS) they may work OK. However a more efficient filesystem (such as a unix FFS) will cause I/O problems. This is not the filesystem or the drive. What happens is that the drive is plugged into a USB port which can't provide the current draw required by the drive. When an slow filesystem is used, the current draw is low and it works. However the higher speed the for the higher bandwidth filesytem increases the current draw, and voila, the disk starts erroring out. You can solve this by connecting the drive to another USB port (perhaps ones on the back of a computer with direct power), or by using a powered USB hub.

Jazz

• The Jazz drives were a cool idea for a while. They are basically removable media hard disks. The lowering costs and increasing capacity of fixed hard disks put a dent in their market.
• Last I looked, the a 2GB disk cost $100, and you can buy a 320 GB IDE disk for $100. Ouch.
• That being said, it was still a small way to carry larger capacity random-access writable media with you.
• 1 & 2 GB Capacities