The Castlewood Orb was a removable rigid-disk drive introduced by Castlewood Systems in 1998.
The first version had a capacity of 2.2 GB, but in 2001 a version with 5.7 GB was released (the 5.7 GB drive could read the older 2.2 GB disks). Disks came formatted for either Macintosh or IBM compatibles, and drives were available in external and internal versions.
Castlewood Systems was formed by several former employees of SyQuest Technologies. Shortly after the Orb was released, SyQuest brought a lawsuit against Castlewood for misappropriation of trade secrets and Iomega later brought another lawsuit against Castlewood for patent infringement.
The Orb disk competed with the Iomega Jaz, but internally the two products differed. The Jaz cartridge used two internal disks, while the Orb used a single disk, allowing for lower costs.
Castlewood Systems ceased operations around 2004.