초록 ▼

The present invention includes a keyboard encoder which encodes a key selected by an operator. The encoder is isolated from a bi-directional bus by an isolation circuit. When a key has been selected a key code is made available for reading by a separate CPU. The separate CPU enables transfer of the

The present invention includes a keyboard encoder which encodes a key selected by an operator. The encoder is isolated from a bi-directional bus by an isolation circuit. When a key has been selected a key code is made available for reading by a separate CPU. The separate CPU enables transfer of the key code from the encoder to the bi-directional bus and then reads the key code. The separate CPU acknowledges receipt of the key code and provides feedback to keyboard operator by sending a bank and light selection code to the keyboard over the bi-directional interface bus, after the isolation circuit has been reactivated and after a function, to be performed by the separate CPU and specified by the key code, has been started. The isolation circuit prevents the key code and the bank and light selection code from becoming intermixed on the bi-directional bus. The bank select code is used to select a bank of light code decoders which activate a light corresponding to the light code. The light activated stays lit until another key is selected. The transmission of a second bank and light selection code after a single key is selected can be used to activate an additional light associated with the selected key.

대표청구항 ▼

A keyboard and interface circuit connectable to a computer, said circuit comprising: a keyboard having keys and lights corresponding to the keys; encoder and detection means for detecting key selection and producing a key code corresponding to a selected key; a parallel bi-directional interface bus,

A keyboard and interface circuit connectable to a computer, said circuit comprising: a keyboard having keys and lights corresponding to the keys; encoder and detection means for detecting key selection and producing a key code corresponding to a selected key; a parallel bi-directional interface bus, having one set of bi-directional lines where all lines are bi-directional, for both transferring the key code to the computer and transferring a first light selection code corresponding to the key code from the computer; isolation means for isolating said encoder and detection means from said bi-directional bus; and decoder means for decoding the first light code and activating the light corresponding to the selected key.