NOTE: Free essay sample provided on this page should be used for references or sample purposes only. The sample essay is available to anyone, so any direct quoting without mentioning the source will be considered plagiarism by schools, colleges and universities that use plagiarism detection software. To get a completely brand-new, plagiarism-free essay, please use our essay writing service.
One click instant price quote
Abstract: MS-DOS was the dominant PC operating system before the introduction of Windows. DOS was originally based on a cloned version of CP/M created by Seattle Computer which Microsoft secured, modified and offered to IBM for use in the first PC. IBM gave early PC users a choice of PC DOS, CP/M or UCSD Pascal, but everyone chose DOS because it was far cheaper. IBM coded the kernel of BASIC into its copyrighted ROM, which also included the BIOS, and designed the system so that only its machines could run the enhanced BASIC A interpreter. Microsoft's introduction of its own MS-DOS and the 'blind engineering' of IBM-compatible BIOS technology paved the way for legal PC clones.
Advances over the years included support for higher-density floppy drives, networking support in DOS 3. 0 and later, and larger partitions under DOS 4. 0. DOS 4. 0 was buggy and short-lived, but the stable DOS 5. 0 and DOS 6. 0 introduced many bundled utilities. DOS is not dead and is still used by millions as the operating system underlying Windows 3. x, although Windows NT and Windows 95 do not require DOS. The tale of Microsoft Corp.
securing a 16 -bit disk operating system from Seattle Computer, modifying it, and selling nonexclusive rights to IBM for the PC is often told. Originally, Bill Gates recommended that IBM secure Digital Research's CP/M- 86, but at the time, it was not ready and no deal could be made with Gary Kildall for a definite delivery date. In a 1986 Computer Shopper interview, Kildall said he knew that Tim Paterson of Seattle Computer had cloned CP/M and made some changes, but he was not inclined to go to court over it. So Microsoft secured the system that was to become PC DOS for IBM computers and MS-DOS for everyone else making PC clones. Up to that point, the purchase of Coca-Cola from an Atlanta druggist had been the best American business deal, but Bill Gates's deal for DOS became the foundation of one of the greatest fortunes in the world.
When IBM released the PC in August 1981, it gave consumers a choice of operating systems: Microsoft's IBM PC DOS, Digital Research's CP/M- 86, or UCSD Pascal. The catch was that PC DOS cost $ 60, CP/M- 86 was $ 175, and UCSD Pascal was $ 450. The public got the message, and everyone bought PC DOS. To a user, the original PC DOS looked much like CP/M, except for the adaptation of the File Allocation Table (FAT) and the elimination of some of CP/M's backward notation, which required you to move a file from the A: drive to the B: drive by typing: "PIP B: A: Filename. " DOS changed this to "Copy A: Filename B: . " Other simple command changes included a change in the system prompt from A: to A> . DOS also supported 5. 25 -inch disks rather than the original 8 -inch CP/M floppies.
The cranky old CP/M line-editor ED was almost the same as PC DOS's EDLIN. As an experienced CP/M user, I was able to use PC DOS after a short reading of the manual. PC DOS 1. x supported two floppy drives, two serial ports if you added a serial board to your PC, and a printer port. No hard drives were supported. The first versions of PC DOS used 180 K 5. 25 -inch floppy disks, but this was quickly increased to 320 K.
The Wide-Open Road IBM had encoded the kernel of BASIC into the copyrighted system ROM, which also contained the basic input / output system (BIOS) -- the system startup software. The ROM-Basic was an integer-based Basic, but when you loaded the PC DOS system disk, you got IBM's extended BASIC A. If you tried to load BASIC A into a computer without the IBM ROM, the system would crash. IBM felt this protected its system as well as its copyrighted BIOS. However, Microsoft, which had the right to sell the operating system to others, was working on a non-IBM version it called MS-DOS. This OS was released to the public in March 1982, and was originally used in the non-IBM-compatible 8088 and 8086 computers made by Digital Equipment Corp. , Texas Instruments, and a few others.
These systems could run some PC applications specially configured for them, but within a short time, they were withdrawn because the public demanded PC compatibility. A few PC clones appeared claiming to be non infringing of IBM's copyrights; they used MS-DOS as their operating system. Microsoft provided a version of extended Basic for MS-DOS, which did not require the Basic kernel in a BIOS ROM. They called it Gee Wizz BASIC (GW BASIC). This was equal to BASIC A and could run the same applications.
However, IBM took the clone makers to court and put them out of business by proving that IBM's copyrights for the BIOS had been violated. Finally, through "blind engineering, " several BIOS ROMs were developed that were completely compatible with IBM and proved to be non infringing. The way was now wide-open for PC clones to use MS-DOS, and more computers were sold by the clone makers than by IBM. To obtain the operating system from Microsoft, clone makers had to sign an agreement to pay Microsoft a royalty for every copy of DOS sold with their computers. Make Way for Change Since the first versions of PC DOS and MS-DOS did not support hard drives, several third-party manufacturers provided hard drives for PCs that ran with special device drivers.
When the IBM XT came out in March 1983, version 2 of PC DOS/MS-DOS was released, providing support for hard drives and larger-capacity floppies. The popularity of hard drives and their constantly increasing storage capacity resulted in software applications that expanded to fill the space available to them. It quickly became obvious that the limits to RAM and hard drive storage capacity built into MS-DOS were going to cause problems in the near future. The 8088 CPU used in the PC and XT computers was merely a 16 -bit processor running with an 8 -bit bus. It was limited to addressing 640 K of RAM.
With the advent of the more powerful 268 CPU, IBM released the IBM Advanced Technology (AT) computer. This new machine required a major upgrade of the operating system, so version 3. 0 of DOS was released. This version supported higher-density 5. 25 -inch floppies with 1. 2 MB, and version 3. 1 added support for 3. 5 -inch floppy disks. By version 3. 3, DOS had become a stable operating system; it took many users a long time to upgrade beyond this version. One problem remained, however, and that was the limits on RAM memory. Certain programs required much more than 640 K of RAM, and the 286 could directly address up to 1 MB of RAM.
To use this extra capacity for applications such as spreadsheets, users started to add extra memory boards that could use expanded memory with special software. Version 3. 0 and higher also supported memory-manager programs that moved DOS and other programs into upper memory, which was defined as the area between 640 K and 1 MB. This would free more of the conventional 640 K for running programs. DOS 3. 0 and subsequent versions also supported networks, which became popular as groups of PCs were connected.
DOS users bought suites of DOS utilities, such as Norton Utilities and PC Tools, to add much-needed functions that had been lacking. These included programs to defrayment the disk drives, restore deleted files, and repair minor recording problems with the disk drives. Then, when a plague of viruses began infecting PC systems, users installed virus-detection and -removal programs. Providing various utilities and enhancement programs for DOS became a large part of the software industry. Then came DOS 4.
The main thing DOS 4, which allowed for the removal of 34 MB limits on hard drive partitions. Before DOS 4, if you had a 40 MB drive, you had to divide it into two logical drives no larger than 34 MB. But DOS 4 was considered "buggy" and was short-lived. It was quickly replaced by DOS 5, which included enhancements required for the newer 386 and 486 computers as well as many software improvements. DOS 5: The Sequel DOS 5 's new features benefited owners of 286 -based machines and owners of 386 and 486 computers. DOS 5 provided advanced memory management; the Shell program, which offered some of the features of Windows 3. 0, such as task-swapping; a DOS macro capability; enhanced operating commands; support of higher-capacity drives; and a complete online help system.
In addition, Microsoft added a completely new QBASIC interpreter -- a vast improvement over BASIC A and GW BASIC. This included EDIT, the full-screen editor meant to replace the old EDLIN line editor. EDIT also worked with a mouse and with VGA color. Many users who had not upgraded from version 3. 3 went to version 5 because of the EDIT screen editor alone. With all the improvements and enhancements, PC DOS/MS-DOS became a fully mature operating system. However, DOS did not satisfy the computer industry or many users who wanted to be free of the 8 -character names and the RAM and hard drive limits inherent in the system.
Many people also wanted a 32 -bit, multitasking, multiuser, graphical user interface with network management functions. IBM and Microsoft devoted themselves to developing the next-generation operating system to replace DOS. Their partnership fell apart in the war over who would control the future system and what the system would look like. Both combatants were constrained by the existence of tens of thousands of DOS users, who were the potential customers for any new operating system.
These people fully expected to have their existing systems maintained and supported until they were ready to switch over to any new system. For this reason, Windows had to be installed over DOS, and OS/ 2 had to enable a dual-boot capability to keep a DOS window and support Windows. Neither company could completely eliminate DOS; the public would not buy a new system without an overwhelming reason. IBM had learned this lesson the hard way when it tried to eliminate the AT bus structure.
Meanwhile, other operating systems were competing for PC users' business. Versions of Unix were developed for use on Intel CPUs and attracted users who wanted multiuser operation and were not concerned with the graphics operation. The original PC operating-system company, Digital Research, remained in business selling its multitasking Concurrent DOS, and later, a completely MS-DOS-compatible system called DR DOS. Including many functions that were not provided as part of MS-DOS 5, it required the purchase of extra utility software. DR DOS had another function: it provided an alternative for clone makers who did not want to pay Microsoft royalties. The existence of DR DOS also let Microsoft claim that it didn't have a monopoly on the OS market.
However, just to make sure DR DOS wasn't too competitive, Microsoft came out with MS-DOS 6, which featured all kinds of utilities that were formerly separate programs. These included Microsoft Backup, which let you back up to all kinds of disks and tape; Double Space, which effectively doubled the storage space on your hard drive; Scandisk, which found and repaired problems on your disk drives; Defrag, which de fragmented your hard disks and sped their operation; Anti-Virus, which found and eliminated viruses; Delete sentry, which let you restore files you'd accidentally deleted; and other commands to help improve overall operation. Microsoft did run into some legal problems with Double Space, but quickly released a new version to avoid them. Meanwhile, IBM, which was mainly trying to sell OS/ 2, came out with its own inclusive version called PC DOS 7. Novell bought Digital Research, and DR DOS became Novell DOS, serving as a warning to Microsoft not to make changes to DOS or Windows that would make Novell NetWare obsolete. Novell, however, has since dropped DR DOS from its software offerings.
As for the future, it seems that DOS is not quite dead. Millions of users have yet to upgrade to Windows 95, which, like Windows NT, does not sit on top of DOS but is its own DOS. But the time is no doubt coming. Like an old soldier, the DOS that made the PC famous will gradually fade away to be replaced with newer Windows systems.
Free research essays on topics related to: floppy disks, hard drives, ms dos, disk drives, cp m
Research essay sample on Ms Dos History Of Operating Systems
