题目

求一篇关于酒店的3000字左右的英文文章

提问时间：2021-03-20

答案

In 1972,IBM introduced flexible diskettes as a medium for loading programs into mainframe computers.Because the disks were so flexible,they were nicknamed floppy disks.They are inexpensive,small,and easy to handle,store,and send through the mail.Most computers have at least one floppy disk drive.Floppy disks,also called diskettes,are available in two sizes:3.5 and 5.25 inches.For MS-DOS based computers,the 3.5-inch disks are available in 720-kilobyte (double - density),1.44-megabyte (high - density),and 2.88-megabyte (extended - density) capacities.The 5.25-inch disks have a density of 48 tracks per inch,whereas high-density disks have a density of 96 tracks per inch.Almost all 3.5-inch floppy disks have a density of 135tracks per inch.The earliest models of floppy disks were single-sided.The addition of another read/write head in the disk drive led to the use of double-sided floppy disk,and doubled the capacity of the disk.Today,all floppy disks are double-sided.If you examine a 3.5-inch floppy disk,you will see that a metal sleeve covers the read/write slot.When you insert the disk into a disk into a disk drive,the metal sleeve slides back,exposing the read/write slot.The read/write head of the floppy disk drive can position itself over specific tracks.Because of the metal sleeve and the rigid plastic casing,the 3.5-inch floppy disk is less vulnerable to damage than the 5.25-inch floppy disk.To use the files or programs that are on a floppy disk,you must first insert the disk into a floppy disk drive.Floppy disk drives are commonly referred to as the A drive and the B drive.Check your computer manual to see which drive is A and which is B.