Tuesday, June 1, 1999

How Windows CE devices are designed and built

.KEYWORD companions
.FLYINGHEAD BEHIND THE SCENES
.TITLE How Windows CE devices are designed and built
.FEATURE
.SUMMARY Ever wonder why it seems to take so long for a new device to come to market? You might hear about it in November, but not be able to buy it until June. Why? Of course, we have the answer. Read this informative article by Chris De Herrera and you’ll get a behind the scenes view of how products are created.
.AUTHOR Chris De Herrera
Each of the Windows CE devices you see today went through a development cycle that was very demanding on the manufacturing firm and the people that work for it. One of the first decisions an OEM (i.e., Original Equipment Manufacturer) has to make is which product to produce. Microsoft offers their Windows CE design in a number of flavors: Handheld PC, Professional Edition, palm-sized PC and Auto PC. The OEM chooses which of these base specifications to follow when building their device and that, in part, decides RAM, number of buttons, screen size, number of colors etc. Also, the OEM can choose which specifications to exceed — such as increasing the base size of the internal RAM, enlarging or shrinking the size of the display, and so forth.

Each system starts out as a design group’s idea of what the product should be. This is based on the decision about the overall product type. The development team discusses their ideas with various individuals and outside representatives to decide if the product mix is right. There’s a lot of listening and learning about what’s important and what’s not, what’s possible for a given price point, and what’s not. The features and capabilities that the design group decides on go forward as a mockup.

The next step is to create a series of mockups of the unit out of foam, plastic or wood. The mockups are all a little different so that a user can compare and contrast the features and capabilities of the devices. After that is observation — actually putting a user in a room with the prototypes and seeing which one she likes best and why. This may go through a couple of rounds while the product’s case design and ergonomics are finalized.

While that’s going on, the electrical designers are working on the design of the system board and support for the peripherals and ports that have been specified by the design group. The designers also choose the manufacturer of critical components: adapters, displays and keyboards of the new units as well. As part of this process, the components are designed to fit in the case form factor used in the mockups. Also, designers work with outside vendors on creating any specialized connectors or adapters needed to build the systems. All of these systems are not yet optimized. Early units tend to have Flash ROMs (Read Only Memories) for easy upgrades and are slower than the final units that will be produced.

While the hardware designs are being created, the software engineers are working on the drivers and applications that will be bundled with the device. The software people receive a copy of the whole system software release for the specific device they have chosen to create. Once they get this from Microsoft, then it’s up to the OEM engineers to migrate that release to their hardware. This design process is done in emulation first and later moved to the first prototypes for testing.

Now for the magic moment