Keyboard

Keyboard input is still a significant method of input. In many applications data is prepared off-line at a key to disk or key to tape workstation.

Keyboards are still the most appropriate method for entering text and are convenient for entering small volumes of data. Most office PC's use the keyboard for data input. However it is slow and therefore unsuitable for large volume data input, it is error prone and it is labour intensive and therefore expensive.

Key-to-disk systems

In organisations where large amounts of data are collected on forms which then have to be keyed in for later processing (a batch processing system) an entire computer system consisting of a processor, dozens of terminals and central disk storage may be dedicated entirely to data entry.

One terminal is nominated as the supervisor’s terminal, from whose screen the supervisor can see exactly what every data entry operator is working on and how many keystrokes per hour and how many errors everyone is making.

Completed batches of data are stored on disk from where they are either downloaded to the main computer over a communications link, or transferred to magnetic tape which is physically removed and taken to the main computer room.

Batch processing

In a batch processing system, documents such as sales orders are collected into batches of typically 50 documents. A data control clerk has the responsibility of:

• Counting the documents
• Checking each one visually to see that the customer has entered essential details
• Calculating a control total of some crucial field such as Total Payable, for the entire batch
• Calculating hash totals of other fields such as size or quantity (see later)
• Filling in a batch header document to show, e.g.

• batch number
• number of documents in batch
• date received
• control total
• hash total
• logging the batch in a log book

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