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Dos disk size Pc#
MS-DOS soared in popularity with the surge in the PC market.
![dos disk size dos disk size](https://i.ytimg.com/vi/IPkGS2AaUi4/sddefault.jpg)
Gates and co-founder Paul Allen had written Microsoft BASIC and were selling it on disks and tape mostly to PC hobbyists. Until its acquisition of QDOS, Microsoft had been mainly a vendor of computer programming languages. At that time the use of disks for storing the operating system and data was considered cutting edge technology. It had originally been used by IBM in the 1960s in the name of an operating system (i.e., DOS/360) for its System/360 computer. The two versions were initially nearly identical, but they eventually diverged. Microsoft renamed it PC-DOS (the IBM version) and MS-DOS (the Microsoft version). And in what was to become another extremely fortuitous move, Bill Gates, the not uncontroversial co-founder of Microsoft, persuaded IBM to let his company retain marketing rights for the operating system separately from the IBM PC project. Microsoft initially kept the IBM deal a secret from Seattle Computer Products. Although it was completed in a mere six weeks, QDOS was sufficiently different from CP/M to be considered legal. QDOS was written by Tim Paterson, a Seattle Computer Products employee, for the new Intel 16-bit 8086 CPU (central processing unit), and the first version was shipped in August, 1980. CP/M (Control Program for Microcomputers) was written by Gary Kildall of Digital Research several years earlier and had become the first operating system for microcomputers in general use. QDOS had been developed as a clone of the CP/M eight-bit operating system in order to provide compatibility with the popular business applications of the day such as WordStar and dBase. MS-DOS 1.0 was actually a renamed version of QDOS (Quick and Dirty Operating System), which Microsoft bought from a Seattle company, appropriately named Seattle Computer Products, in July 1981. This was Microsoft's first operating system, and it also became the first widely used operating system for the IBM PC and its clones. When IBM launched its revolutionary personal computer, the IBM PC, in August 1981, it came complete with a 16- bit operating system from Microsoft, MS-DOS 1.0. In spite of its very small size and relative simplicity, it is one of the most successful operating systems that has been developed to date. MS-DOS (Microsoft Disk Operating System) is a single-user, single-tasking computer operating system that uses a command line interface.
Dos disk size windows#
This was only fixed in Windows 95 OSR2 with FAT32, which permitted huge disks - up to 2TiB - with much finer granularity.īut all of DOS 4, 5 and 6.x permitted disk partitions of up to 2GiB.MS-DOS history, description, commands, clones, future outlook LINFO Roughly 20-30% of disk space would be wasted because of this granularity as inaccessible "slack space". This became disastrous over 1GiB where the granularity was 16KiB. files were allocated with a granularity of 8KiB and even a 1 byte file took 8KiB.
![dos disk size dos disk size](https://i.imgur.com/apsUNtY.jpg)
However, disks over 512MB used inefficient 8KiB clusters - i.e. This is the one that IBM adopted into MS-DOS 4 and it became the standard. The max cluster size was 16KiB so the max disk size was 65535*16KiB = 2GiB. It used an extension of FAT16 that allowed bigger clusters - still just 65,535 of them, but multiple 512 byte sectors per cluster, permitting bigger partitions. The one that caught on was Compaq DOS 3.31. Of course, anything that directly accessed disk data structures, like a defragger or a disk-repair tool such as Norton Utilities was 100% guaranteed to catastrophically corrupt any such extended disk setup. Lots of vendors implemented hacks and extensions to allow bigger disks, but they were all mutually incompatible and many failed to work with some 3rd party software. The server OS was 3Com 3+Share if anyone remembers that.) Messy as hell but all you could do without 3rd party "disk extenders" such as Golden Bow's one. (I built an MS-DOS fileserver with a 330MB hard disk once - it had drive letters C:, D:, E:, F:, G:, H:, I:, J:, K: and a leftover 11MB L: drive. MS-DOS 3.3 supported one primary and an extended partition containing as many 32MB "logical drives" as you wanted. MS-DOS 3.2 supported two partitions per drive, so 2 x 32MB. MS-DOS 3.0 supported a single hard disk partition (per drive) of up to 32MB. MS-DOS 2.x did, but just one, of up to 10MB. No, the DOS limits were /much/ earlier and older.