EP0077658A2
Expired / Lapsed
EP
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Keyboard scanning and interface method and circuit
Assignee: Convergent Technologies Inc
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Filing: 1982-10-15
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Granted: —
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Expires: 2002-10-15
Abstract
Abstract A method and apparatus is disclosed for allowing simultaneous depression or chording of a multiple number of keys on a keyboard coupled through an interface circuit to a computer operating system. An arbitrary association can be made to the chord which is distinct from the association made with its component keys. A dedicated processor system in the keyboard peripheral scans and stores in a dedicated memory the identity of all keys detected in the depressed state during the scan of the keyboard. For transmission to the computer operating system each key depression detected during the scan is represented as an 8-bit binary component and the most significant bit of each binary component is set to the same one of the two permissible binary values, except for the most significant bit of the binary component representing the last depressed key detected during the scan of the keyboard. The most significant bit of that component is set to other of the two permissible binary values.
Inventors
- 👤 Richard W. Lowenthal
- 👤 Gregory V. Walsh
- 👤 Steven C. Seike
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 12:58
CPC Classifications
H; H03; H03M; H03M11/00; H03M11/003
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
49 words
A method for communicating keyed input information comprising the steps of: scanning a keyboard to detect activated keys; memorizing said activated keys; and communicating said listed keys as a binary word or arbitrary bit length determined by the number of activated keys detected during one scan of said keyboard.
Claim 2
Independent Claim
49 words
A method for communicating keyed input information comprising the steps of: scanning a keyboard to detect activated keys; memorizing said activated keys; and communicating said listed keys as a binary word or arbitrary bit length determined by the number of activated keys detected during one scan of said keyboard.
Claim 3
Dependent Claim
77 words
The method of claim 1 wherein said step of memorizing includes the steps of setting a selected bit of each portion of said word corresponding to each activated key to one of two permissible binary values except the last activated key detected during said one scan of said keyboard, and setting a selected bit of the portion of said word corresponding to said last activated key is set to the other of the two permissible binary values.
Claim 4
Dependent Claim
14 words
The method of claim 2 wherein each selected bit is the most significant bit.
Claim 5
Dependent Claim
82 words
The method of claim 1 or 3 wherein said step of memorizing includes the steps of: storing representations of said activated keys in a map memory; and storing codes corresponding to said stored representations in a ring buffer memory. 5. The method of claim 4 wherein said step of communicating includes the steps of: indicating that a change in status of said activated keys has occurred; and reading said stored codes from said ring buffer memory when said change in status occurs.
Claim 6
Independent Claim
70 words
A method for communicating keyed input information from a keyboard to a data processing system comprising the steps of: cyclically scanning each row of keys of a plurality of rows forming the keyboard; detecting the activated keys within the scanned row; generating a memory address for each activated key; addressing a first memory with said memory address; and storing a representation of each activated key at said address generated therefor.
Claim 7
Independent Claim
70 words
A method for communicating keyed input information from a keyboard to a data processing system comprising the steps of: cyclically scanning each row of keys of a plurality of rows forming the keyboard; detecting the activated keys within the scanned row; generating a memory address for each activated key; addressing a first memory with said memory address; and storing a representation of each activated key at said address generated therefor.
Claim 8
Dependent Claim
26 words
The method of claim 6 further comprising the step of translating each representation stored in said first memory into a second memory as a unique code.
Claim 9
Dependent Claim
98 words
The method of claim 6 or 7 wherein the unique code stored in the second memory is a series of binary bits further comprising the steps of setting a selected bit of each series stored in said second memory to one of two permissible binary values except the series last stored in said second memory during one scan of said keyboard, and setting a selected bit of said series last stored to the other of the two permissible binary values, whereby each of the series is identified as a component of a multiple component word representing a chord.
Claim 10
Dependent Claim
19 words
The method of claim 8 wherein each selected bit is the most significant bit of the series of bits.
Claim 11
Dependent Claim
91 words
A keyboard communication circuit coupled to a plurality of keys of a keyboard, comprising: scanning means for addressing said plurality of keys and for detecting the activation status of each one of said keys; memory means coupled to said scanning means for storing a first representation of each activated key detected during the addressing of the plurality of keys; and communicating means coupled to said memory means for selectively transferring said stored first representations as distinct further representation of all activated keys detected during one addressing of said plurality of keys.
Claim 12
Dependent Claim
91 words
A keyboard communication circuit coupled to a plurality of keys of a keyboard, comprising: scanning means for addressing said plurality of keys and for detecting the activation status of each one of said keys; memory means coupled to said scanning means for storing a first representation of each activated key detected during the addressing of the plurality of keys; and communicating means coupled to said memory means for selectively transferring said stored first representations as distinct further representation of all activated keys detected during one addressing of said plurality of keys.
Claim 13
Dependent Claim
80 words
ll. The circuit of claim 10 wherein said first representation is a binary word, and said memory means includes a means for setting a selected bit of each word corresponding to each activated key to one of two permissible binary values except the last activated key detected during one addressing of said plurality of keys, and means for setting a selected bit of the word corresponding to said last activated key to the other of the two permissible binary values.
Claim 14
Dependent Claim
17 words
The circuit of claim 11 wherein each selected bit is the most significant bit of the word.
Claim 15
Dependent Claim
56 words
The circuit of claim 10 or 12 wherein said memorizing means includes a map memory for storing the first representations corresponding to said detected activated keys; and a ring buffer memory for storing a code corresponding to each first representation stored in said map memory, said communication means forming said further representation from said stored codes.
Claim 16
Dependent Claim
43 words
The circuit of claim 13 wherein said communicating means includes means for indicating that a change in status of said activated key has occurred; and means for reading said stored codes in said ring buffer memory when said change in status is indicated.
Claim 17
Independent Claim
73 words
An apparatus for communicating keying input data to a data processing system comprising: scanning means for interrogating the keys of the keyboard and for detecting activated keys; memory means coupled to said scanning means for storing codes associated with detected activated keys; and communication means for communicating an arbitrary number of stored codes to the data processing system determined by the number of activated keys detected during one interrogation of the entire keyboard.
Claim 18
Independent Claim
73 words
An apparatus for communicating keying input data to a data processing system comprising: scanning means for interrogating the keys of the keyboard and for detecting activated keys; memory means coupled to said scanning means for storing codes associated with detected activated keys; and communication means for communicating an arbitrary number of stored codes to the data processing system determined by the number of activated keys detected during one interrogation of the entire keyboard.
References Cited (Backward Citations)
No citation records indexed.
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