NCR 5932, Руководство пользователя

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1-8 Chapter 1: General Overview
For many years, the standard in keyboards was the keyboard style
known as
101-Key . In recent years, with the broad acceptance of
Graphical User Interfaces, keyboards have added one or two GUI keys
and current keyboards are now called 102-Key or 103-Key style. The
NCR PS/2 keyboard does not contain these GUI keys. The NCR USB
keyboard does not have reserved positions for those keys, but permits
those keys to be added using the keyboard programmability (see
Keyboard Programmability ).
Cappable Keys
Both USB and PS/2 NCR keyboards include keys that accept customer-
specified key caps and labels. For example, one customer may wish to
include buttons for
DEPT , CLASS , and SKU on his keyboard. A
different customer may have no use for these keys, but may want
TIRES , BATTERIES , and ACCESSORIES on specific keys. Cap-able
keys allow for this customization.
Double-High / Double-Wide Keys
Along with cap-able keys comes the ability to put caps over pairs of
plungers, resulting in larger keys. On a standard keyboard, the space
bar, the Enter key, the Tab, Delete, Shift, Control, and Alt keys are all
wider than the rest. These keys are implemented with one or two
plungers, but they cannot be modified for different functionality. On
NCR keyboards, the cap-able keys may be capped in pairs. Key caps
are available that cover two plungers, either
double-high or double-wide .
When two keys are capped individually, the keyboard firmware must
detect each one as a different key, and must send different messages to
the host computer to indicate different keys were pressed. When the
same two keys are capped together, the firmware must somehow know
this and send only one message.