【 Weak current college 】 computer why not B disc

In the era of the birth of the computer just, no hard drive, then data stored mainly rely on floppy disk. Floppy drive as they occupy A and B letter of location, and later as the application of the hard disk, it can only be used in order to occupy the letter C disc later.
A is for 3.5 inch disk reserved
B is for 5.2 reserved
A, B are two letters to the diskette drive, over the past five-inch floppy disk drive, install two floppy drive B disc when there is now a general safety, there is no floppy disk drive B disc.
DOS
A disc is the original 3.5 inch floppy disks
B disc is the original 5.3 inch floppy disks
After drive c is the hard drive partition
Windows follow the DOS partition settings
Furthermore 5.3 inch disk later exit market
So there is no b disc
Windowsxp can customize letters
This means you can set a plate for B disc