View this article at: http://www.macnn.com/articles/05/04/04/20gb.ipod.mini.in.07/ Monday, Apr 04, 2005 9:30am New microdrives make 20GB iPod mini possible in 2007 Hitachi will offer 20GB one-inch hard drives (the size used in the iPod mini) by 2007, according to the company. The density breakthrough represents a refinement in perpendicular recording. Today, hard drives record and store data in a longitudinal fashion, with the read/write heads scanning over a horizontal plane. In perpendicular recording, data bits are aligned vertically, allowing for more data to be squeezed into a defined area, explains ZDNet UK. The hard drives store about 4.5GB per square centimeter using this technology. The technology will allow Hitachi to offer a 20GB microdrive and an 8.9cm drive for desktops that will hold a terabyte. Currently, microdrives top out at 6GB, such as the drive used in Apple's latest iPod mini.