The magneto-optical drive manufactured by Canon Inc. is the primary mass storage device. This drive technology was relatively new to the market, and the NeXT is the first computer to have used it. MO drives were cheaper but much slower than hard drives; Jobs negotiated Canon's cost of $150 per blank MO disk down to a retail cost of only $50, and they have an average seek time of 96 ms. The design makes it impossible to move files between computers without a network, because each NeXT Computer has only one MO drive and the disk can not be removed without shutting down the system. Storage options proved challenging for the first NeXT Computers. The drive's limitations of speed and capacity make it insufficient as the primary medium running the NeXTSTEP operating system.