Line Printer
A line printer is a device that is engineered to print an entire line at a time. The best line printers can print up to 3,000 lines per minute; however, on average they reach speed between 600 and 1200 pages per minute. This translates to 10 to 20 pages per minute. While these machines are extremely fast, they are not capable of printing graphics. In addition, the quality of the print is relatively low and the printer is noisy. There are four line printer design types.

Drum Printer
A drum printer is a type of line printer where the characters are engraved on to a number of printing wheels. These wheels form a large drum that spins at a high rate of speed. As the desired character reaches the position it should be printed at a hammer will strike the paper from behind. This causes the paper to push against the ribbon and the drum to get an imprint of the desired character. These production line printers have the order of the characters staggered around the drum so that multiple hammers do not have to strike at the same time.

Chain Printers
A chain printer is a line rider printer that has the characters engraved on a horizontally moving chain or bar. These discount line printers function in the same manner as the drum printer except for the fact that the chain can be changed out by the operator. This advantage allows the operator to choose a chain with a smaller set of characters when appropriate, which makes the printer significantly faster.

Bar Printers
The bar printer is a line printer daemon design that is similar to the chain printer. However, these models are slower and less expensive. These cheap line printers have bars that move from right to left and left to right rather continuously in one direction.
Comb Printers
Comb printers are a combination of a line printer and a dot matrix printer. This design uses a comb of hammers to print a portion of a row of hammers. The comb moves back and forth to complete the line. This type of printer is significantly faster that traditional dot matrix printers.