Character and signal generator for detecting keyboard disconnected condition generated by an interrupted booting process and generating signal indicating that keyboard is now coupled thereto

摘要

A signal generator for generating an F1 keyboard keystroke and a clock signal responsive to expiration of a time delay sufficient for a computer to which the generator is coupled to partially complete a "boot" process to a point where the computer has detected a "keyboard disconnected" condition and entered a "wait" state. The generated F1 keystroke provided to the computer by the signal generator indicates to the computer that a keyboard is now coupled to the computer, allowing the computer to continue the "boot" process.PPIn the embodiment disclosed, a time delay circuit provides an enabling signal after expiration of the time delay to a latch circuit, a clock signal generator, and a coupling circuit. The output of the latch circuit initially enables loading of a 12-bit shift register with data from a plurality of switches and thereafter switches the mode of the shift register from "load" to "shift. " The clock signal clocks the data from the shift register, and the coupling circuitry couples the clock signal and the data from the shift register to the computer as it is clocked from the shift register. Termination circuitry detects the end of the data from the shift register and provides a disabling signal to the clock generator, ending the data stream upon occurrence of the last data pulse.