| 摘要 |
In a data processing system wherein operator entry of data is provided an array of alpha numeric display units is utilized not only for indicating operand entries and operating results, but also as an operator message prompting medium for steering the operator to correct operand entry or system errors. Upon processor recognition of a particular entry or other errors an assigned error signal is generated which blocks the operand or operation result signal from the display units. In one embodiment the error signal is received at a programable logic array associated with each display unit to provide a signal for accessing a memory which in turn provides the appropriate letter pattern signal for the display unit to spell out an error prompt message. An alternate embodiment provides for serial generation of the letter pattern signals for each display unit and rapid sequential actuation of the display units to spell the prompt message.
|
