To use it, you simply need to install DDR 266, 333 or 400 RAM modules, plug it to the PSU, and connect it to the SATA port; it will then be recognized as a HD by the system.
In theory, one could use it without any problem on a Mac, except the backup application bundle with it which is only for Windows. However, the iRAM only accepts at most 1GB RAM modules, which will then make a 4GB HD, based on today’s requirements and availability, this is rather too small to get a full performing system installed on.
