If entries must be delayed pending computer processing of prior entries, the delay should be indicated to the user.
Additional Information:
If processing delay results in control lockout, this could be signaled by a change in the appearance of the cursor, accompanied by an auditory signal. In some applications, it may be desirable to ensure that the keyboard and other control devices are automatically locked until the user can begin a new transaction. This would be true when processing the current transaction will affect the results of subsequent user actions. In other applications, it may be possible to permit users to continue work while previous transactions are still being processed. Deletion or change of a displayed cursor in itself may not be a sufficient indicator of keyboard lockout. Auditory signals will be particularly helpful to a user who may not look at the display when making entries. Following control lockout, computer readiness to accept further entries should be indicated to the user.