To address these compromises on Ethernet and DVD, we designed a small external system-powered device we called the DiscDock. This is primarily a gigabit Ethernet and DVD burner dock with a USB hub, and we later added other cheap and handy add-ons like a DVI port for a computer monitor, an HDMI port for HD video and audio, and an unpowered eSATA port for an external hard drive. We never got around to settling how this dock would connect to the WorldBook. USB wouldn't drive Ethernet up to gigabit speed, but it would be better than 10/100. ExpressCard seems ideal, but it would take much longer to design the dock, primarily because the cable between the card and the dock would have to be custom-made. In either case, a separate video cable from the DisplayPort would be needed to drive the displays.
Under the cover
The notebook portion of WorldBook is fairly straightforward, with some innovative twists that only gearheads would notice in the specs but which benefit all users. The platform is AMD’s "Puma," utilizing AMD's Turion X2 Ultra dual-core CPU, AMD M780G chipset, and the ATI/AMD Radeon Mobility 3800 GPU. The CPU has 1MB of dedicated L2 cache per core, on-board memory, and bus controllers, a HyperTransport 3.0 scalable I/O bus, independent voltage and frequency control for each core, and a slew of power-saving features that will remain latent due, in part, to manufacturers' tendency to spend little time tuning systems and pre-loaded OSes for anything other than generic Intel x86.
Being devoted to one supplier and a cohesive platform, and knowing that the least capable model in our product line will always be a 2.4GHz dual-core Turion X2 Ultra with a discrete GPU, we don't have to dumb anything down. We'll trade the usual deep discounts on component pricing offered to exclusive customers for a couple of months split between Dresden and Ontario (AMD and ATI engineering operations, respectively), sponging up all we can from their engineers.
ATI's standard display driver will need some adaptation for our GreenZone power conservation. WorldBooks have a 16:9, true HD aspect ratio display. This is great for spreading out multiple windows or documents horizontally, or, of course, enjoying widescreen presentations and movies. When you're not deeply multitasking, when all you're doing is word processing or checking your e-mail, as much as two thirds of the backlight power is wasted. GreenZone shuts off the backlighting for the left and right sides of the display, leaving a 4:3 ratio virtual display in the center. This amounts to yanking the cord from your widescreen monitor and plugging in your old squarish CRT. It's not something a notebook GPU is designed to handle.
The GPU can offload a number of math-intensive tasks from the CPU. MPEG-2 and MPEG-4 video decoding and encoding provide a stirring example of the power savings that can be derived from offloading. When decoding video with the GPU, the CPU can practically idle. An unaided CPU can be overwhelmed by software MPEG-2 processing, and decoding Blu-ray or Transport Stream (HD cable box, for instance) on an x86 CPU is a cruel thing to do to innocent silicon. ATI's integrated graphics processor accelerates MPEG-2 playback, but when graphics memory is shared with the CPU there is always a price to pay.
We see great potential in the use of GPUs for cryptography. We configured full disk encryption into WorldBook, and we're planning to borrow the GPU's resources to make encryption work in real-time during periods of heavy demand. If you're auto-saving a Word file every five minutes, software disk encryption will suffice. If you're reindexing a 50GB database, building a huge development project, or transcoding high-def video down to an iPod, hardware encryption will be a big help.