cathode-ray tube (CRT) terminals, printers, and
Magnetic Ink Character Readers
Magnetic ink character readers read magnetically
inscribed information (like on a bank check) and
translate it to machine code.
Scanners read text, drawings, and photographs and
convert them into electronic representations of the
Bar-code readers scan data encoded in special bar
codes using reflective light and translate them to
machine code. Examples are the code on the front of this
manual and the codes on supermarket and department
Key-to-Online Data Entry
Using a key-to-online data entry terminal, a person
enters input data into the computer directly from the
point of origin. This eliminates the need for human
intervention between source recording and the ultimate
processing by the computer.
Magnetic Tape Units
Magnetic tape units move magnetic tape across
read/write heads that read and write the information.
Characters are recorded (written) on the tape in the form
of magnetized spots along the entire length of the tape.
On tape, data is stored in a sequential manner. In
sequential processing, the CPU must begin searching at
the beginning of the tape and check each record until the
desired data is found.