Реферат: DOS And Unix Essay Research Paper Compare

for disk operating system, the term DOS can refer to any operating system, but

is most often used as shorthand for MS-DOS. Originally developed by Microsoft

for IBM, MS-DOS was the standard operating system for IBM-compatible computers.

The initial version of DOS was somewhat uncomplicated and resembled another

operating system called CP/M. Subsequent versions have become increasingly

sophisticated, however DOS remains a 16-bit operating system without support for

multiple users or multitasking. The earliest forms of DOS were crude and

utilized only a few commands, but as computers became more advanced, so did DOS.

By keeping up with technology, DOS was implemented into more ?user friendly?

operating systems. However, as more sophisticated operating systems were

released, DOS became less important. ?Today, cyberpunks involved with the

latest OS trends joke that DOS stands for ?Dad?s Operating System?? (Comerford,

23). In 1980, IBM asked the Microsoft Corporation to produce the operating

system for its first personal computer, the IBM PC. Prior to this, a company

called Seattle Computer Products had sold an operating system called 86-DOS to

Microsoft. Microsoft hired the author of 86-DOS, Tim Paterson, in April of 1981

to modify the system, and renaming it MS-DOS (Microsoft Disk Operating System),

it was released with the IBM PC. Thereafter, most manufacturers of personal

computers licensed MS-DOS as their operating system (Brittanica, 1). Limitations

of the early PC?s hardware were a big influence on MS-DOS. Although the 8088

model computer had a 1Mb address space, IBM decided to allocate the first 640K

of this to RAM, and the rest to ROMs, video boards and other things.

Consequently, MS-DOS was set up to support programs whose maximum size was 640K.

Version 1.0 of DOS was released along with the IBM PC in August 1981. It

occupied 12K of the systems 640K of memory, was somewhat compatible with CP/M

and, much like CP/M, supported only a single directory. By contrast, even the

first version of UNIX had a full hierarchical file system. In addition, Version

1.0 supported only a 160K single sided 51/4-inch floppy diskette. Version 1.1

was released by Microsoft in October 1982 and supported double sided 320K