Printers: Basic Questions price - and running costs? compatible with your computer? colour or black and white? speed of printing? what resolution? amount of paper the tray can handle? will it take the paper sizes you want to use? do you need to print envelopes?

Dot Matrix Printer price: the least expensive printers. basic idea: a print head with small blunt pins hits an inked ribbon: like a typewriter except that the same pins produce all char- acters. The precise configuration of pins changes - to allow different characters to be represented - according to the instructions sent by the computer. speed: in the range 1 to 18 pages a minute

Dot Matrix Printer - 2 resolution: poor for 9 pin; fair for 24 pin. noise level: high ink: on the ribbon - replace it when dry paper: single sheet or continuous fanfold SUMMARY - old, but worth considering if price is more important than output quality or quietness. Ideal for multicopy forms - the impact is needed to print through carbons.

Ink Jets price: cheap to middle range basic idea: a print head sprays ink through small holes onto the page speed: in the range of half to four pages per minute resolution: 180 to 720 dots per inch noise level: low

More on Ink Jets ink: in cartridges - replace when empty paper: single sheet. Most ink jets will take envelopes, labels and transparencies. SUMMARY: widely used, offering high quality output relatively cheaply. Colour ink jets are especially popular, being much less expensive than laser printers but still giving good results.

Laser Printers price: middle to top of the range basic idea: in essence a copier. Instead of dealing with characters it simply produces a high quality photocopy. speed: between 4 and 30 pages per minute resolution: 300 to 1200 dots per inch noise level: low

More on Laser Printers ink: a fine powdered ink, toner, is stored in a cartridge. Replace when empty. paper: single sheets up to A4 and higher, envelopes, labels and transparencies (the last must be for laser or photocopier use) colour: output from colour laser is dearer than that from colour inkjet, but better.

Still More on Laser Printers multifunction: some laser printers do other jobs - faxing, scanning and photocopying memory: because of the way they work - storing pages before printing - lasers have at least 1 MB of memory, often a lot more. For high resolution (600 + dpi) and/or complex graphics and/or A3 output, a lot of memory is needed.

Finally on Laser Printers Laser output requires a printer language, software to tell the printer how to print. There are two types of printer language: PCL: Printer Control Language. PCL lasers are fine for routine office work: cheaper but with less graphic capability than... Postscript lasers, able to print complex graphics, fonts and colours. Very popular in graphic design environments.

For a readable account of laser printers, try this web page: ~poota/lpbook/01-chp1.html

Other Types of Printer Solid Ink: high quality but relatively cheap colour images on paper or transparency Thermal-Wax: sharp, rich images that don’t smear Dye Sublimation: also known as thermal dye transfer printers; very expensive but producing images that look like colour photographs.

Fonts Character sets of a given design and size. The font used here is Times New Roman.... this is Arial Most printers come with built in, resident, fonts (you can add to them). Resident fonts print faster than those on your computer. There are two basic kinds of font: TrueType and Bitmapped

Buffers and Spoolers Computers send data much faster than print-ers print it. To avoid the computer waiting, data is dumped into an intermediate store for release to the printer at a manageable speed. This frees up the processor for other tasks. These intermediate stores take two forms: buffers and spoolers

Buffers & Spoolers - 2 A buffer is a section of printer memory that receives the computer’s output. When the buffer is full, the computer must wait before sending any more.. A spooler is a program that stores informat- ion ready for printing on the computer. Far bigger documents can be stored on spoolers than on printer buffers. Windows comes with a built-in print spooler.