Sardar Patel University 2007 B.E Computer Science Computer peripherals (CP313)(Internal ) - Question Paper

[B] Advantages of Dot-matrix Printer over Non-impact printer

Dot-matrix printer Non Impact printer
1. Dot-matrix printers are bit image impact kind of printers
1. common non-impact technologies are inkjet, thermal, Laser etc.
2. generate the image by striking the output media through ribbon where ink can be used to print by 1st forming the needed shape using a matrix of dots 2. do not strike any ribbon or paper to produce the image instead ink spraying is used based on electrostatic magnetization or heat process to produce the needed image on the paper
3 can be used to print multipart forms because cannot print just through a ribbon but also through several sheets of paper and carbon paper to print multipart carbon copies in single pass. 3 can not be used to print carbon copies or multipart copies in a single pass
4 hammers striking against the ribbon generates much noise. 4. soundless operation makes them very popular
5 quality of output is not much high compare to non-impact printer ( 50 to 150 DPI resolution) 5 produce very high quality output compare to Dot-matrix printer ( 300 to 1800 DPI resolution)
6 cost is lower than non-impact printers 6 costly compare to Dot-matrix printer
7 Can output on any media 7 cannot print on any media
8 max six pages per minute can be printed 8 max 16 pages per minute can be printed by non-impact kind printers




Q.2 [A] Justify your answer:
Low level formatting is not given at user end in voice coil mechanism.
? Voice coil based head actuator with servo dose not get effected by the temperature change or the life of the hard disk drive, because its positioning system it self correcting.
? If the patter expands or contracts due to change in temperature then the head will the automatically search and move to accurate position.
? this kind of drives do not require frequent low level formatting to accurate the relative position of the info on the disk surface with respect to the head position ,as needed by the stepper based hard disk drives.







[B]What is write precompensation?
? The particles on the HDD platters will slowly shift to the needed position because of the attraction and repulsion ranging from them. This process of writing the data closer or further to compensate for the attraction and repulsion of the magnetic particles is called write pre-compensation.
OR

Earning:   Approval pending.