Line Printers (Drum and Chain Printer)

Line Printers: They are known as line printers because they print one line at a time. Characteristics of a line printer:

1. Characters are raised on the drum or chain.
2. Different fonts cannot be used for printing.
3. High printing speed and quality.

There are two types of line printers: Drum printers and chain printers.

Drum Printers: In a drum printer characters are raised in a cylindrical drum. Values of all characters are stored in the printer buffer. When a character has to be printed, the printer sends the information to printer buffer.  Then, printer drum is rotated and when the code match is done the character is printed by striking the hammer.  There is a carbon ribbon in between the drum hammer and paper.  So, when the hammer strikes an impression is produced in the paper.

Chain Printers: Instead of a drum, chain with raised characters is used in these types of printers. Values of all characters are stored in the printer buffer. When a character has to be printed, the printer sends the information to printer buffer.  Then, printer chain is rotated and when the code match is done the character is printed by striking the hammer. There is a carbon ribbon in between the chain hammer and paper.  So, when the hammer strikes an impression is produced in the paper.