Versions of MS-DOS

I've included this table of MS-DOS versions to assist in understanding how MS-DOS evolved. The history of DOS is not tested on the A+ exam, but as I've found out it does help and is a useful reference.

Version	Date	Main Changes
1.0	1981	86-QDOS written by Seattle Computer Products is renamed to MS-DOS by Microsoft. IBM refers to it as PC-DOS.
1.25	1982	Supports double-sided discs (PC-DOS 1.1)
2.0	1983	Supports 10MB hard discs and 360KB floppy discs
2.11	1983	Supports extended character sets
3.0	1984	Supports 32MB hard discs 1.2MB floppy discs
3.1	1984	Supports networking
3.2	1986	Supports 31/2", 720KB floppy discs
3.3	1987	Supports PS/2 computers, partitioning, 31/2, 1.44MB floppy discs
4.0	1988	Supports extended memory, graphical user interface DOS shell and disc partitions above 32MB
5.0	1991	DOS can now run in high memory, supports 2.88 floppy discs and full screen editor
6.0	1993	System tools such as DoubleSpace, Anti-Virus, Defragmenter, MSBackup added
6.2	1993	CHKDSK replaced with SCANDISK, CD-ROM caching added
7	1995	Supports long file names, part of Windows 9x.