And they can replicate it as many times as they want. ZDNet's John Lombardo discusses the installation of Linux on the DiskOnChip module in a tutorial article. Sometimes you can't justify the time and expense of developing a dedicated hardware platform for your embedded application. Perhaps the quantities are too small or the market is unproven. However, even under these circumstances you still don't want to ship a big klunky box with a hard drive.
Hard drives wear out over time, they draw lots of power and get very hot.
Besides, customers know a PC when they see one. The wristwatch runs the Linux 2.2.1 kernel with the ARM patch from Ben Williamson. According to IBM, there are certain issues regarding the non-availability of this patch in the latest stable kernel release. The ARM processor that powers the watch runs at 19MHz, is RISC based and which according to estimates is almost equivalent to a 100 Mhz Pentium. The motherboard for the watch was fabricated at IBM's Japan research center.