MS-Dos History, History of Operating Systems
MS-Dos History, History of Operating Systems
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...