Iomega make Zip drives. THey have been recently associated with a problem known as the "click of death". When this occurs the drive is having problems reading the disks. My own drive is acting in this way at the moment, although I have it from a reliable source that Iomega will unconditionally replace any drive with this problem. The current version comes in both internal and external models and the disk capacity is 250 Meg. I do not belive that the newer drives are subject to this problem.
Hope this helps.