Abstract

A text-editing system having a keyboard for the input of character and text-editing operation signals, writable text storage, display and writable display storage, and control storage storing groups of microinstructions. A system control is responsive to an interrupt signal from the keyboard for decoding an input signal and deriving therefrom internal control signals for operation of the system, including modification of the display storage and text storage. Apparatus is provided for inputting the character and text-editing operation signals in either of two alternative modes. A select/store circuit is responsive to a select/store signal to select from the text storage character and operation signals modified according to a first alternative mode and to store them in a special condition storage. The system control is thereafter responsive to a recall signal to disable the keyboard interrupt, retrieve the stored signals, and operate according to them. Also, apparatus is provided for inputting the text-editing operation signals in association with a special input condition signal. Displayable representations of such operation signals are accessed, displayed and stored in text storage, but the operation is not carried out. The select/store circuit replaces the displayable representations with executable representations.