If you are developing applications with the Apple IIGS, you may need to
be able to identify which keyboard is being used: the ADB or the Apple IIe
(that is, the logic board connector for the keyboard located at site J13).
Since the Apple IIGS was primarily designed to use an ADB keyboard, the
only way to determine if a keyboard is connected to J13 and not the ADB
bus is to make an assumption. The assumption will be made by a response --
or lack of response -- from the AsyncADBReceive ($0D09) Toolbox routine.
The AsyncADBReceive routine will NOT receive a keyboard response if there
is no ADB keyboard present.
(NOTE: A wrong assumption could be made at this point -- for instance, with
an Apple IIGS with its ADB keyboard disconnected. The application being
constructed should ask if the user is ACTUALLY using an Apple IIe which has
been upgraded to an Apple IIGS.)
Complete information about the AsyncADBReceive routine can be found in the
Apple IIGS Toolbox Reference (ISBN #0-201-17746-3): Volume 1, Section 3,
page 14.