Patent EP0441032A2 successfully refreshed from Google Patents.
EP0441032A2
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EP
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Keyboard emulation system
Assignee: HP Inc
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Filing: 1990-11-23
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Granted: —
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Expires: 2010-11-23
Abstract
Abstract The system unit (16) of an IBM compatible personal computer generates a distinctive audible "Beep" signal from the system unit's own sound transducer (32) in response to the successful decode of a barcode label (26) in a keyboard emulation data collection device such as a barcode reader (10). To initiate the generation of such a Beep by the system unit, the keyboard emulation system simulates (114,116) a benign error condition (OOH;FFH) which does not affect the operation of any application programs resident in the system unit and which does not require any modifications to the operating system or any special device drivers for its proper operation. The successful collection of encoded character data and transmission of that data to the keyboard port (28) of a host computer by a relatively unsophisticated operator is further enhanced by built-in logic (40,42,44) for reliably and simply deducing which keyboard communication protocol from several candidates is currently in use and for deducing the status of the computer's Caps Lock flag by eliciting a Reset Status Indicators command from the system unit. If the Caps Lock flag is in its shifted state, all case sensitive data is automatically transposed (114) so that it will be correctly interpreted.
Inventors
- 👤 Mckee D. Poland
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 16:59
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/10; G06F13/105; G06F13/107; G06F3/00; G06F3/01; G06F3/02; G06F3/0202; G06F3/021
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
183 words
For use with a computer system unit (16) or computer terminal unit comprising a keyboard port (28) and a sound transducer (32) and utilizing a predetermined keyboard communication protocol for inputting data from a keyboard unit (18) via the keyboard port as a sequence of keyscan codes, the protocol including provision for signifying at least one predetermined benign error condition within the keyboard unit which causes an audible error signal to be generated by said sound transducer, a keyboard emulator (10) comprising: input means (36,46,48,24,34,50,38,40,42) for converting a machine-readable symbol (26) into a digital representation of a message comprising one or more character codes; and output means (36,46,48,42,44,52) responsive to the input means for transmitting said message to said keyboard port in accordance with said keyboard communication protocol and for emulating said predetermined benign error condition whenever said input means successfully translates character codes into a corresponding sequence of keyscan codes, whereby whenever a sequence of keyscan codes corresponding to a said machine readable symbol is received at the keyboard port from the keyboard emulator, the computer will produce an audible error signal.
Claim 2
Dependent Claim
70 words
A keyboard emulator according to claim 1 which comprises an elongated contact-type barcode reader (10) which does not contain any sound transducer; said benign error condition is emulated by transmitting a predetermined keyscan code to said system or terminal unit, and said system or terminal unit is programmed to cause said sound transducer to generate an audible error signal whenever said predetermined keyscan code is received at said keyboard port.
Claim 3
Dependent Claim
48 words
A keyboard emulator according to claim 2 wherein said computer is an IBM PC compatible computer which in its standard configuration generates an audible "Beep" in response to a keyscan code of "FFH" and said benign error condition is signified by at least one such "FFH" keyscan code.
Claim 4
Dependent Claim
48 words
A keyboard emulator according to claim 2 wherein said computer is an IBM PC compatible computer which in its standard configuration generates an audible "Beep" in response to a keyscan code of "OOH" and said benign error condition is signified by at least one such "OOH" keyscan code.
Claim 5
Dependent Claim
24 words
A keyboard emulator according to claim 2 wherein said machine-readable symbol includes a portion which is converted and translated into said predetermined keyscan code.
Claim 6
Dependent Claim
48 words
A keyboard emulator according to claim 1 wherein said keyboard emulator is an elongated wand which does not contain any sound transducers, and said computer system or terminal unit contains an internal sound transducer means programmed to generate an audible "Beep" in response to said predetermined keyscan code.
Claim 7
Dependent Claim
67 words
A keyboard emulator according to claim 1 further comprises status means (44,30,32,34,36,46,48) responsive to a status command from the computer for deducing status of a shift state status flag, and transposing means responsive to the deducing means (44,130,132,134)and the input means for transposing shift states of predetermined keyboard characters prior to encoding by the output means whenever said shift state status flag is in an activated state.
Claim 8
Dependent Claim
102 words
A keyboard emulator according to claim 7 wherein the keyboard is a Mode 2 IBM compatible keyboard, the system unit or terminal unit is an IBM AT or PS/2 compatible system unit, the status means transmits a predetermined status change keyscan code prior to each transmission of a decoded and converted message to the computer, said status command is a Reset Status Indicators command transmitted by the system unit to the keyboard unit in response to said predetermined status change keyscan code, said predetermined keyboard keys are alphabetic keys, and said predetermined status change keyscan code is a Caps Lock keyscan code.
Claim 9
Dependent Claim
127 words
A keyboard emulator according to claim 1, further comprising: verification means for verifying whether the message is a legal message; header means for generating a "good read" message header comprising at least one predetermined keyscan code signifying said benign error condition; and communication means responsive to the verification means and the header means for transmitting the legal message header and the keyscan codes corresponding to the legal message to the keyboard port in accordance with the predetermined keyboard communication protocol; and wherein:- said verification means further comprises misread detector means for detecting a "no-read" condition signifying that the machine readable symbol being processed by the input means could not be converted into a legal message and said message transmission means transmits a "no-read" message in response thereto.
Claim 10
Dependent Claim
38 words
A keyboard emulator according to claim 9 further comprising mode means for determining whether said keyboard communication protocol is a particular predetermined protocol, and wherein said header means and said communication means are responsive to said mode means.
References Cited (Backward Citations)
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