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printed circuit cards from distributors and place them inside the robot. We can also pur-
chase computer chips from distributors and build our own printed circuit cards, a diffi-
cult proposition for the casual robot designer.
We can purchase complete computer systems on a card, which will accept our soft-
ware and provide connectors for the signal lines we need to control the robot. This is
often the most economical method of integrating computers into the design, unless large
quantities of robots will be manufactured.
The companies that sell computers have invested millions of dollars to make their tech-
nology available for our use. We gain time, dollars, and reliability by sharing and taking
advantage of their effort. Because the technology has been made so readily available to
others, many third-party designs are also available for us to use, such as the following:

Third-party hardware Most computers have connectors on them that enable
us to use the “bus.” We’ll define the term later, but suffice it to say, a bus allows
third-party companies to design hardware that will plug right in to the computer.
Dozens of printed circuit boards (PCBs) and other conveniently packaged cir-
cuitry are available.
Third-party software It’s not unlikely that other companies have written soft-
ware we can use. If the computer we choose is “special purpose” (to be defined
later), then several companies have probably written software that takes advantage
of the special features of the computer. We can purchase this software and use it
in various ways:
Freeware Often an author of software will make it freely available for others
to use. One can search for “freeware” on the Internet, qualified by words that
describe the software needed. Sometimes the author will ask for attribution or
have other requirements.
Shareware Shareware is much like freeware, except the author often requests
payment if the shareware is used in a robot. One can search for shareware in the
same manner as freeware and one should read the restrictions very carefully.
Make copies of the author’s requirements and save them if questions should
arise later. Searching for shareware takes some time, but it can be a very valu-
able endeavor. If nothing else, it can tell us how difficult our software effort
will be. If it’s easy to write and valuable, somebody else will have written it
already. If it’s hard, nothing remotely close will be available in shareware. We
can also discover shareware that comes close and, along with it, the authors who
might be employed to modify it for our project.
Licensing Large software operating systems, tools, and application software
usually have licensing requirements. Contact the company that sells the soft-
ware directly for information.