The Flash Drive and Storage

• The zip disk is a variant on the floppy drive, built by Iomega. These disks are typically between 250MB and 2GB, although some versions such as the portable zip disk have smaller capacities, down to 40MB. A zip disk and a zip drive are different, although they operate on some of the same technologies. A zip disk is an older technology and has essentially been replaced by alternatives, including the zip drive, also called a thumb drive or flash drive. This article describes the mechanical processes of zip disks and how information is stored and accessed from them.
  
  

Mechanics

• Nothing moves in a zip disk. The term "drive" persists because computers read and write flash-drive data using the same interface and commands as for a normal disk drive. Zip disks consist of one small printed circuit board within a metal, plastic or rubber case, needing no further protection. The USB connector is typically protected by a removable cap or by retracting inside some cover in the disk.
  
  

Drive Usage and Process

• Drives are split up into large blocks of EEPROM (Electronically Erasable Programmable Read-Only Memory), and each block must be entirely rewritten if it is to be changed. Memory stores information in an array of memory cells made from floating-gate transistors. These "NOR flash cells" can be changed from the logical value of 1 to 0 by applying voltage. Because all that changes is electrical current, there are no moving parts. When a disk is put into a computer, the computer powers the circuit board connected to the memory. The memory can then be accessed and written to, all electronically.