This is an old revision of this page, as edited by Codegen86(talk | contribs) at 12:04, 9 July 2013(Removed erroneous, unsourced statement again. "[DOS 5] was the last version of DOS that IBM and Microsoft shared the full code for" as the PC DOS article states.). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.Revision as of 12:04, 9 July 2013 by Codegen86(talk | contribs)(Removed erroneous, unsourced statement again. "[DOS 5] was the last version of DOS that IBM and Microsoft shared the full code for" as the PC DOS article states.)
OEM adaption kits—all Microsoft releases prior to version 3.2 were OAKs only
Shrink-wrapped packages for smaller OEMs (system builders)—beginning with MS-DOS 3.2 in January 1986, Microsoft offered these in addition to OAKs
End-user retail—all versions of IBM PC DOS (and other OEM-adapted versions) were sold to end users. DR DOS began selling to end users with version 5.0 in July 1990, followed by MS-DOS 5.0 in June 1991
Intel releases the 8080 (cost $360), which has a 16-bit address bus that can address 216 (65,536) memory locations, or 64 KB of memory. The dominant mainframe at the time, the IBM System/360, can address 224 (16,777,216) memory locations, or 16 megabytes (MB) of memory.
IMS Associates, Inc. releases the IMSAI 8080, a clone of the Altair 8800, and ship a large number of disk subsystems with a promise that an operating system would follow.[19]
1975 market shares for low-cost data recording devices, according to a Venture Development Corp. study: Cassettes 73%, Floppies 22%, Cartridges 5%. The cassette was expected to retain its leadership position through 1980.[20]
1976
Kildall adapts CP/M to the IMSAI hardware, rewriting the parts that manage devices like diskette controllers and CRTs. Having adapted CP/M for four different controllers, and somewhat reluctant to adapt it to yet another, Kildall designs a general interface, which he calls the BIOS (Basic Input/Output System), that a good programmer could change on the spot for their hardware.[18][19] This approach would be reinvented years later as the "hardware abstraction layer." Kildall founds Digital Research and releases CP/M version 1.3 as a commercial product, at $70 per copy. His wife sends diskettes to customers responding to an ad they ran in Dr. Dobb's Journal, whose editor Jim Warren pushed for sale of CP/M to the general public. Demand for the diskettes was slow at first.[7][11][18]
IBM introduces additional hardware components for its 3600 finance communication system, including the first double-sided (dual head) floppy drive.[21] ITC adjusts Flippy (now a registered trademark) production to accommodate the new drive.[22]
Shugart introduces the (single-sided) minifloppy, the first 51⁄4-inch floppy drive.[23]
1977
Torode's Digital Systems runs an ad in Byte for its Altair/IMSAI (S-100) bus floppy disk system.[24]
IMSAI marketing director Seymour I. Rubinstein paid Kildall $25,000 for the right to run CP/M version 1.3, which eventually evolved into an operating system called IMDOS, on IMSAI 8080 computers.[19][25] Other manufacturers follow and CP/M eventually becomes the de facto standard 8-bit operating system.
Tandon Magnetics files a patent for its double-sided ferritedisk read-and-write heads, which improved on IBM's design by employing a fixed transducer on one side and a movable transducer on the other side, and offered its Series 200 heads to OEMs.[26][27] Eventually IBM, Shugart and other manufacturers became licensees of Tandon's patent.[28][29] Later, Shugart introduces their double-sided, double-headed, double density minifloppy drive.[30]
1978
Intel releases the 16-bitIntel 8086 microprocessor, which has a 20-bit address bus that can address 220 (1,048,576) memory locations, or one megabyte of segmented memory.
Paterson takes his working prototype board to Microsoft to try it with Stand-alone Microsoft BASIC, which Bob O'Rear developed for the 8086 by simulating the 8086 chip on a DEC computer. After eliminating a few minor bugs, Microsoft had a working 8086 BASIC.[25]
Microsoft and Paterson attend the National Computer Conference in New York City to show Microsoft's 8086 BASIC running on Seattle Computer's system, sharing Lifeboat Associates' ten-by-ten-foot booth. At that meeting, Paterson is introduced to Microsoft's MDOS (later renamed to MIDAS), which used the File Allocation Table (FAT) file system.[11][25][32]
July
Intel releases the Intel 8088 microprocessor, a lower cost variant of the 8086 which has an 8-bit external data bus instead of the 16-bit bus of the 8086 (the 16-bit registers and one megabyte address space were unchanged). To the programmer, the 8086 and 8088 instruction sets are identical, except for execution speed.[33]
November
Seattle Computer Products ships its 8086-based computer, which runs Stand-alone Microsoft BASIC. No operating system is available for it.
1980–1995: Important Events in DOS History
1980
April
Paterson begins writing an operating system for use with Seattle Computer Products' 8086-based computer, due to delays by Digital Research in releasing an operating system for the 8086 and 8088.
Microsoft introduces the Z-80 SoftCard, which gives Apple users the ability to run CP/M.[34]
IBM first contacts Microsoft to look the company over. Their secret Project Chess needs both programming languages and an operating system.
September
Paterson's "Quick and Dirty Operating System", crammed into 6 KB of code,[36] is shipped by Seattle Computer Products as 86-DOS.[25]
Allen negotiates an agreement with Seattle Computer for a nonexclusive sublicense for 86-DOS to an unnamed OEM customer for $25,000. All that was left was to translate the terms into a formal contract within 60 days.[8]
October
Digital Research introduces CP/M-86 for Intel 8086/8088 microcomputers. The file format of CP/M, Release 2, was retained for compatibility.[37] Like CP/M, CP/M-86 consists of three major modules: the BIOS, BDOS (Basic Disk Operating System) supporting 60 system calls and the CCP (Console Command Processor). New system calls are mainly for the new memory allocation scheme that CP/M-86 uses.[38]
November
IBM signs a contract to license Pascal, COBOL, FORTRAN and BASIC compilers, a BASIC interpreter and an operating system for Project Chess from Microsoft.[8]
1981
January
Microsoft and Seattle Computer formally sign their agreement.[25][39]
February
O'Rear gets 86-DOS to run on IBM's prototype computer. 86-DOS had to be converted from 8-inch to 51⁄4-inch floppy disks and integrated with the BIOS, which Microsoft was helping IBM to write.[11] An Intellec ICE-88 in-circuit emulator expedited the debugging.[36][40]
May
Paterson leaves Seattle Computer Products for Microsoft and joins O'Rear to finish DOS.[25]
July
Microsoft buys all rights to 86-DOS from Seattle Computer Products, initially for an additional $50,000 and favorable licenses back from Microsoft.[41] After settling a 1986 SCP lawsuit, the total cost to Microsoft was $1 million.
IBM combined SYSINIT with its customized ROM BIOS interface code to create the BIOS extensions fileIBMBIO.COM, which deals with input/output handling, or device handling, and added a few external commands of their own: COMP, DISKCOMP, DISKCOPY, and MODE (configure printer) to finish their product. The 160 KB DOS diskette also included 23 sample BASIC programs demonstrating the capabilities of the PC, including the game DONKEY.BAS. The two system files, IBMBIO.COM and IBMDOS.COM, are hidden. The first sector of DOS-formatted diskettes is the boot record. Two copies of the File Allocation Table occupy the two sectors which follow the boot record. Sectors four through seven hold the root directory. The remaining 313 sectors (160,256 bytes) store the data contents of files. Disk space is allocated in one-sector clusters. DOS 1.0 diskettes have up to 64 32-byte directory entries, holding the 8-byte filename, 3-byte filename extension, 1-byte file attribute (with a hidden bit, system bit and six undefined bits), 12 bytes reserved for future use, 2-byte last modified date, 2-byte starting cluster number and 4-byte file size. The two standard formats for program files are COM and EXE. The third kind of command processing file is the batch file. AUTOEXEC.BAT is checked for, and executed by COMMAND.COM at start-up.[44] Special batch file commands are PAUSE and REM. I/O is made device independent by treating peripherals as if they were files. Whenever the reserved filenamesCON: (console), PRN: (printer), or AUX: (auxiliary serial port) appear in the file control block of a file named in a command, all operations are directed to the device.[11] The video controller, floppy disk controller, additional memory, serial and parallel ports are added via 8-bit ISAexpansion cards. Delivery of the computer is scheduled for October.[47]
October
An InfoWorld article asks, "Which Operating System Will Prevail?". Potential software developers must decide whether DOS or CP/M-86 will become the IBM PC standard. Rubinstein asserted that CP/M would be the winner. Nevertheless, MicroPro has made sure that WordStar will be available for both.[48]
November
Many of the approximately 50,000 attendees of the Northeast Computer Show in Boston keep IBM's booth packed with people interested in the new IBM Personal Computer and the Datamaster.[49] A two-page IBM ad in InfoWorld features a picture of the components of the PC and invites readers to write to IBM's Personal Computer Software department who will consider programs submitted by outside programmers for publishing by IBM.[48][50]
December
Digital Research releases MP/M 2.0 and MP/M-86multi-user or concurrent single-user multiprogramming monitor control programs (operating systems) which support multiterminal access with multiprogramming at each terminal.[7][51] Kildall told InfoWorld that it took Digital Research three months to develop CP/M-86, while MP/M-86 (suggested retail $500) took four-man-years (two actual years). Solving the problem of concurrency, among other things, accounted for the extra MP/M-86 development time. In concurrent systems, several functions, organized by the operating system, run simultaneously, using different files. These functions operate in the background, or multiground if there is more than one function operating. While this is happening, the user works on another task using the terminal screen, i.e., the foreground. The minimum system memory requirement for MP/M-86 is 128 KB.[52]
1982
January
The U.S. Justice Department drops its 13-year case against IBM, that had sought to break up the company that has dominated the computer industry, saying the suit was "without merit and should be dismissed." Government lawyers said the case was outdated because IBM no longer enjoyed a virtual monopoly in the computer industry.[53]Time called it "the case of the century" in 1979, in the midst of a five-year trial in which the defense eventually called 856 witnesses.[54]
Corvus Systems released interfaces to make its line of Winchester disk drive systems and local area network fully hardware- and software-compatible with the IBM PC. Corvus offers storage capacities of 5, 10 and 20 MB on 51⁄4-in. and 8-in. Winchester disk systems. Prices range from $3,750 to 6,450.[55] The Corvus Omninet local network scheme can spread the cost of a hard disk drive among several users.[56]
Digital Research releases CP/M-86 for the IBM Personal Computer, Version 1.0 to IBM.
March
Paterson finishes work on the first DOS upgrade, quits Microsoft and returns to work for Seattle Computer Products.[25]
April
At a recent meeting of the Homebrew Computer Club, members learned about Intel's just-announced iAPX 286 superchip. Digital Research is producing an operating system for the 286. MP/M-286 will take advantage of the processor's memory management and protection. Intel is supplying Digital Research with the hardware to develop and test MP/M-286. Intel's marketing manager also spoke briefly of the planned iAPX 432, Intel's next major processor.[57]
Digital Research announces Concurrent CP/M-86, aka Concurrent CP/M, a new CP/M-86-compatible single-user multitasking operating system. Concurrent CP/M allows users to go from one screen to another at the push of a key and programs to directly address up to 1 MB of memory. The first implementation will be on the IBM Displaywriter. The Concurrent CP/M project was an offshoot of MP/M development, and the two programs share a lot in common, including a real-timenucleus that is the essential element in the system that allows programs to run simultaneously. The enthusiastic introduction of Concurrent CP/M is clear evidence that Kildall is betting on a future with powerful personal computers, not multi-user systems linking dumb terminals to a central processor.[58]
Microsoft runs an ad in InfoWorld promoting their first non-IBM OEM version of MS-DOS.[59]
IBM releases CP/M-86 (price: $240) as the third operating system it is offering for the IBM PC, after a delay for functional, usability and performance testing. For months PC DOS was the only operating system available for the PC. Recently, IBM also released the UCSD p-System. Existing CP/M-86 programs running on other computers must be converted to run on the IBM PC.[60] Partly because CP/M-86 was priced six times higher than PC DOS (price: $40), it fails to challenge PC DOS as the 16-bit industry standard.[61]
IBM releases an upgraded PC with IBM PC DOS 1.1 which supports its Tandon TM100-2 320 KB (327,680 bytes) double-sided, double-density floppy disk drive. The double-sided directory increased from four to seven sectors, allowing up to 112 directory entries, leaving 630 sectors, i.e. 315 clusters (322,560 bytes) for data (cluster size doubled to two sectors). The 2-byte last modified time was inserted at the end of the directory's reserved field, reducing it to 10 bytes.[44]Timestamping on files is useful for incremental backup with the Corvus hard disk. PC-DOS 1.1 still ships on a 160 KB diskette. The DEL command is added as a synonymous name for the ERASE command and REN is an abbreviated name for RENAME. DATE and TIME become internal commands. The EXE2BIN command is added and MODE is enhanced to configure serial ports and redirect printing to a serial port. A "P" MODE option causes continuous retries when a device is not ready, by making a portion of MODE permanently resident in memory.[11] BIOS modifications permit DOS to recognize whether a disk is single or double sided. IBM also released the Microsoft BASIC compiler. All five Microsoft languages are now available—FORTRAN released in December, and COBOL last month. A typical PC with 320 KB of disk storage, keyboard, printer, monochrome display and MDA costs $3695.[65]
June
Microsoft releases the first non-IBM OEM version of MS-DOS.[66] Among the many licensees: manufacturers of non-IBM-compatible systems, such as those using the S-100 bus, e.g. Seattle Computer and Zenith's revolutionary Z-100, which had been released in mid-1981. Most marketed their customized versions of Microsoft's second release as MS-DOS 1.25. Zenith called their MS-DOS variant Z-DOS. Columbia Data Products introduces the MPC, the first PC clone—which runs MS-DOS 1.25—soon followed by others including Eagle Computer. These machines were not 100% IBM PC compatible. Satisfying "near-compatible" OEM requests for IBM compatibility proved difficult, and not until version 3.1 was Microsoft able to supply a system that other OEMs agreed was identical with IBM's.[11]
August
IBM introduces a new 64 KB memory-expansion card, expandable to 256 KB by adding three 64 KB RAM module kits. Two fully loaded expansion cards added 512 KB (cost $2150) to the main board's 64 KB, giving the PC 576 KB of memory.[67] With another 64 KB card, users could reach the 640 KB barrier of conventional memory.
Peter Norton becomes a pioneer in the DOS-based Utility software industry, as the first ad for his Norton Utilities, version 1.0, appears in InfoWorld (sold by Oregon-based Computer Exchange, which promotes itself as "the world's largest computer mail order firm").[71] Norton Utilities features the UNERASE command which solved "a common problem to which there was no readily available solution."[72] Microsoft would not provide a solution until version 5.0 of MS-DOS, and over a decade would pass before Windows 95's Recycle Bin appeared.
Mouse Systems' optical mouse, wired to a Sunworkstation and an Atari 400 running Missile Command, attracts many observers at the Mini/Micro 82 conference in Anaheim, attended by over 10,000 people—and wins a "best new product" award. Interface cards for the IBM PC will be available when the mouse is released in January.[73]
November
Compaq announces the first IBM PC compatible portable computer, the Compaq Portable. It ran on Compaq MS-DOS 1.12. Compaq achieved compatibility legally by reverse engineering through clean room design. The Compaq Portable has a CGA-compatible display adapter which shows its text mode characters with MDA-resolution, effectively combining the virtues of the CGA and the MDA.[74]
1983
January
Lotus Development Corp. releases Lotus 1-2-3, which would become the IBM PC's first "killer application." It was programmed entirely in assembly language and bypassed the slower DOS screen input/output functions in favor of writing directly to memory-mapped video display hardware. This reliance on the specific hardware of the IBM PC led to 1-2-3 being utilized as one of the two litmus test applications for true 100% compatibility.
February
IBM announces a new color display, the IBM 5153 Model 1 for the PC, for presentation of CGA-resolution business data and graphics.[75] Home users can connect a television using a frequency modulator.[46]
The IBM PC/XT, the first PC to store data on a hard disk (10 MB), is announced. It ships with PC DOS 2.0, and introduces nine sectors per track floppy disk formats, which increase floppy storage capacity by about 12%. Single-sided 180 KB (184,320 bytes; 360 sectors) and double-sided 360 KB (368,640 bytes; 720 sectors) diskettes require more than the maximum 340 FAT entries a 512-byte sector can hold, so the FAT size is doubled, leaving 351 clusters (179,712 bytes) for data on single-sided disks and 354 clusters (362,496 bytes) on double-sided. In addition to Microsoft's new commands, IBM adds more including FDISK, the fixed disk[76] setup program, used to write the master boot record which supports up to four partitions on hard drives. Only one DOS partition is allowed, the others are intended for other operating systems such as CP/M-86, UCSD p-System and Xenix. The fixed disk has 305 cylinders (the equivalent of tracks), two platters, thus four sides or heads, and 17 sectors per track, a total of 20,740 sectors or 10,618,880 bytes raw space. With DOS the only partition, DOS's FAT is eight sectors (16 sectors for two copies) and the root directory is 32 sectors long, room for 512 directory entries. With one master and one DOS boot sector, the combined overhead is 50 sectors, leaving 2586 8-sector clusters for data (10,592,256 bytes) and two unused sectors (not enough to form a cluster).[44] A BIOS parameter block (BPB) is added to volume boot records. PC-DOS does not include the FC command, which is similar to COMP. DOS 2 is about 12 KB larger than DOS 1.1 – despite its complex new features, it's only 24 KB of code.[11][77] Under pressure from IBM to leave sufficient memory available for applications on smaller PC systems, the developers had reduced the system size from triple that of DOS 1.1.[36]
April
Digital Research releases the last 8-bit version of CP/M, it was major version 3, often called CP/M Plus. It incorporated the bank switching memory management of MP/M in a single-user single-task operating system compatible with CP/M 2.2 applications. CP/M 3 could therefore use more than 64 KB of memory on an 8080 or Zilog Z80 processor. The system could be configured to support date stamping of files. The operating system distribution software also included a relocating assembler and linker.[78] CP/M 3 was available on the last generation of 8-bit computers.
May
Microsoft introduces the Microsoft Mouse. It comes in either a bus or serial version, with the Multi-Tool Notepad, a mouse-based text editor. Microsoft also introduces Multi-Tool Word, designed to work with the mouse.[79][80]
October
IBM releases the IBM 3270 PC, an IBM PC/XT containing additional hardware which could emulate the behaviour of an IBM 3270 mainframe terminal.
Digital Research releases CP/M-86 Plus Version 3.1, based on the multitasking Concurrent CP/M kernel. It could run up to four tasks at once. CP/M-86 Plus was available for the ACTApricot PC (UK) and the Olympia PEOPLE computer.
The NEC PC-100, modeled blatantly after the Apple Lisa, is the star introduction at Tokyo's Japan Data Show. It runs MS-DOS 2.01, which added support for individual country date, time and currency display formats via the CONFIG.SYS COUNTRY command, and 7000 16-bit Japanese kanji characters.[11][66][81] With the help of Kazuhiko Nishi, leader of ASCII Microsoft, Microsoft arrived early in Japan.[8]
November
The IBM PCjr is announced.[82] It had half-height 51⁄4-inch disk drives and ran PC DOS 2.1,[83] which supported PCjr's ability to run programs from ROM cartridges and slightly different disk controller architecture. Its built-in CGA-compatible display adapter added three special graphics modes which would not be supported by later generation adapters.[74] International modifications in MS-DOS 2.01 were not included because IBM did not want them. PCjr ships first quarter 1984 in limited supply.
Borland is launched by a single full-page ad for Turbo Pascal in Byte magazine. Lacking money to pay for the ad, the company deceives Byte's salesman into running the ad on credit, by hiring extra people so Borland would look like a busy, venture-backed company, making sure the phones were ringing and the extras were scurrying around. Borland expected to sell maybe $20,000 worth of software and at least pay for the ad—they sold $150,000 worth. Without subterfuge, Borland International would almost certainly have folded.[12][84][85][86]
Less than two weeks after VisiCorp announced the release of Visi On (see below), in New York, Microsoft officially announced Windows as "a graphical user interface to cover DOS." Gates said that with Windows, users would finally be able to use their software on any PC without compatibility issues.[87][88]
Clone competition heated up in the past two months, with new microcomputers from Leading Edge, Panasonic, Tandy, Sperry, North Star, Gavilan and others. A similar spate of IBM clones existed during IBM mainframes' late 1960s/early 1970s heyday, when many companies developed plug compatible computers. IBM improved its models and changed specifications so the clones were no longer compatible, and many plug compatible mainframe manufacturers went bankrupt. Suspicious that history could repeat, many recent microcomputer entrants are proud of their technological advances earned at the cost of compatibility, such as portability, faster performance, better graphics, increased memory or a simpler user interface than the IBM PC or PC/XT.[92]
February
Digital Research ships Concurrent CP/M Release 3.1, featuring PC-Mode, which allows users to run either PC-DOS or CP/M-86 applications.[93]
March
Microsoft combined versions 2.1 and 2.01 to create MS-DOS 2.11 for other OEMs. Version 2.11 was sold worldwide and translated into about 10 different languages.[11] It was shipped by every major OEM, including Hewlett-Packard, Wang, DEC, Texas Instruments, Compaq, and Tandy.[66] By June, Microsoft will have licensed MS-DOS to 200 manufacturers.[94]
May
Quarterdeck Office Systems ships their Desq text-mode operating environment which runs on top of DOS 2.0.[95] Desq allows nine windows to be open at the same time. A mouse is optional—the Microsoft, Mouse Systems and Logitech mouse types are supported.[96][97][98]
Accepting the emergence of PC-DOS as a de facto standard, Digital Research announced Concurrent PC-DOS, which allows users to run up to four programs simultaneously using PC-DOS and/or CP/M. Concurrent PC-DOS supports up to four windows and requires 256 KB RAM, with 512 KB recommended. It can support two users, with one attaching a dumb terminal to the micro's serial port.[99] Concurrent PC-DOS, due out by the end of 1984, will be offered for the AT&T 6300.[100][101]
Phoenix Software Associates introduces the first Phoenix PC ROM BIOS which enabled OEMs to build essentially 100%-compatible clones without having to reverse-engineer the IBM PC BIOS themselves, as Compaq had done for the Portable, helping fuel the growth in the PC compatibles industry and sales of non-IBM versions of MS-DOS.[102]
August
Microsoft releases MS-DOS 3.0 to IBM, after a difficult year and a half of grappling with problems of software incompatibility, remote file management, and logical deviceindependence at the network level. In laying the foundation for networking, the core team of five people led by Zbikowski and Reynolds redesigned and rewrote the DOS kernel. Redirector and sharer interfaces for IBM's network adapter card were added, but the redirector itself, which interacts with the transport layer of the network, wasn't ready.[11]
The IBM PC/AT, a computer built around the Intel 80286 microprocessor, with a 16-bit ISA bus, new CMOSclock and 20 MB hard drive, is introduced. It ships with PC DOS 3.0, which adds support for quadruple, or high density (80-track), 15 sectors per track 1.2 MB (1,228,800 bytes; 2400 sectors) floppy disks. Their FAT fills seven sectors (14 for two copies) and root directory 14 (holding up to 224 entries), leaving 2371 1-sector clusters (1,213,952 bytes) for data. The hard disk has 614 cylinders, four sides, and 17 sectors/track, a total of 41,752 sectors or 21,377,024 bytes raw space. The 12-bit FAT design allows for a maximum of 4,078 clusters.[74] DOS cluster sizes are powers of two,[103] so to avoid using 16-sector clusters and support larger hard disks more efficiently, DOS added a new partition type (0x04) for partitions larger than 15 MB, using a 16-bit FAT, which allows a smaller 4-sector cluster size. As a result, DOS 2.x hard disks larger than 15 MB, which used a 12-bit FAT (type 0x01) are incompatible with later versions of DOS.[104] The 286 has a 24-bit address bus that can address 16 MB of RAM, and IBM officially supported expansion to 3 MB. PC DOS 3.0 supported use of extended memory with the VDISK.SYS installable device driver, which allowed configuration of one or more virtual disks (RAM disks). The /E switch caused virtual disks to use extended memory rather than conventional memory.[11] VDISK used a BIOS memory transfer service, known as the Interrupt 15h interface, to avoid switching directly into protected virtual address mode.[74] However, the ROM BIOS routine did switch from real mode to protected mode and back again, a relatively slow process which was not reliable for some applications. PC DOS 3.0 also provided the same international support included earlier in version 2.11. IBM also announced a PC/AT version of the Xenix multiuser operating system, the IBM PC Network (developed for IBM by Sytek and supported by PC DOS 3.1), and a new multitasking windowing software utility called TopView—all will be available in first quarter 1985.[105][106][107][108][109]
IBM introduces the Enhanced Graphics Adapter (EGA), which costs $524 and has 16 KB ROM and 64 KB RAM. An additional 64 KB RAM ($199) comes on a piggyback board called the Graphics Memory Expansion Card. An additional 128 KB ($259) added to the piggyback board produces a fully loaded 256 KB EGA card (total cost: $982). For use with monochrome monitors, the EGA supports MDA-text mode and adds a 640×350 monochrome graphics mode, a slightly lower resolution than the Hercules' 720×348. The EGA has the advantage of being "IBM standard" with built-in BIOS support, while Hercules has the initial advantage of being more widely used and software-supported. For color monitors, all seven CGA modes are supported. 80-column text mode resolution improved from the CGA's 640×200 to 640×350—shy of the 720×350 resolution achieved by Compaq. Three new graphics modes were added, including 16 colors simultaneously from a palette of 64 colors at 640×350 resolution.[69][74][110][111][112] The IBM 5154 enhanced color monitor ($849, planned availability January 1985) is needed to display the increased resolution.[113][114] IBM also announces the Professional Graphics Controller.[70]See also: EGA palettes
November
Microsoft releases MS-DOS 3.1, which added a new local area network supplement Microsoft Networks 1.0 (identified earlier as MS-Net)[115] for use on non-IBM network cards. Microsoft Networks services are provided by a file server which was part of the Networks application and ran on a computer dedicated to the task.[11] Neither MS-Net, nor its successor LAN Manager, was particularly successful competing against market leader Novell, whose product Novell NetWare had a seventy percent market share.[25]
1985
January
InfoWorld names Borland Sidekick 1984 Software Product of the Year (1-2-3 was their 1983 awardee). Sidekick is a memory-resident, or Terminate and Stay Resident (TSR) program that uses a hot-keypop-up window to superimpose a calculator, calendar, notepad, phone dialer, and ASCII table onto PC-DOS software.[116][117][118] Other companies soon discovered this wonderful DOS feature and TSRs began competing for the PC compatible's finite memory space.
Digital Research previews Concurrent DOS 286 in cooperation with Intel. The product functions strictly as an 80286 native mode operating system, allowing users to take full advantage of the protected mode to perform multi-user, multitasking operations while running 8086 emulation.[119]
March
IBM ships their TopView text-mode operating environment.[120]
April
The IBM PC Network program, supporting IBM's network adapter card, is released. It runs on PC DOS 3.1.[121]
At the Spring COMDEX, Intel announces a memory board called Above Board that circumvents the 640 KB memory barrier, and Lotus Development Corp. announces new versions of Lotus 1-2-3 and Symphony intended to make use of the newly available memory. Above Board uses bank switching so the IBM PC and PC/AT can use what Intel and Lotus call the Expanded Memory Device Interface Specification 3.0 (EMS, not to be confused with IBM's extended memory). The specification allows use of up to 8 MB of RAM. Above Board packs up to 2 MB, and two Above Boards can coexist in the same system. A source estimated that 4 MB of RAM would yield about 500,000 cells in a spreadsheet. EMS is implemented with the Expanded Memory Manager (EMM), supplied by the board manufacturer as a CONFIG.SYS DEVICE directive. The specification was publicly released to product developers, and similar memory boards were soon released by others including Tecmar and Quadram.[11][122][123][124]
May
Seven months after its introduction, the EGA has not displaced IBM's first generation of video boards because most developers have yet to adapt their software to it. Among the handful of software packages now fully supporting the EGA is Digital Research's GEM (Graphical Environment Manager). For a number of reasons, software designed for the CGA's graphics mode won't work properly under the EGA's emulation mode, but software designed for the MDA generally does.[125]
Digital Research exposed problems with the emulation features on the C-1 step of Intel's 80286 chip which would not allow Concurrent DOS 286 to run 8086 software in the protected mode. The release of Concurrent DOS 286 was delayed until Intel develops a new version of the chip. Industry observers are by no means certain that Concurrent DOS 286 will ever be able to run existing software effectively in protected mode, even with Intel's refinements to the chip.[119]
June
Digital Research releases Concurrent DOS 86 Version 4.1, an updated version of Concurrent DOS that supports high-end IBM-compatibles, MS-DOS 2.1 applications and Digital Research's GEM software.[126]
AST Research announces the Rampage multifunction board, designed as a superset of the Lotus-Intel standard.[123]
Microsoft says it is joining forces with Lotus and Intel in support of the EMS, which will now be known as the Lotus-Intel-Microsoft Specification. Microsoft plans to integrate expanded memory capabilities into its future systems software products. In conjunction with the announcement, Intel released a new version 3.2 of the specification. Intel said that enhancements in revision 3.2 allow multitasking operating systems to support more easily multiple application programs sharing expanded memory.[128] Application programs communicate directly with the EMM using a software interrupt, bypassing DOS. A new EMM function supported multitasking operating systems by saving and restoring page maps.[66][129]
August
IBM and Microsoft announce a long-term Joint Development Agreement to share specified DOS code and create a new multitasking operating system from scratch, known at the time as Advanced DOS (OS/2 would eventually be released in 1987). The pact was signed in June.[8][130]
Market reaction to IBM's Enhanced Graphics Adapter has not been overwhelming, partly because the EGA's complexity—five custom chips and 12 modes—has slowed software development and the board's price tag has been a damper for many, but the EGA is emerging as the next graphics standard. Lotus expects to release drivers supporting 1-2-3 and Symphony by the end of the month, and Microsoft Chart will join Word and Windows in supporting the EGA. As many as five clone boards—presumably less expensive—are expected to hit the market over the next six months. Chips and Technologies is creating a full, custom EGA chip set. IBM tried to insulate developers from the board and sidestep the driver problem by incorporating the Virtual Device Interface (VDI) from Graphic Software Systems (GSS) of Wilsonville, Oregon (founded in 1981 by four former Tektronix engineers) into the EGA, but many developers are choosing to ignore the IBM VDI. Digital Research has its own Virtual Device Interface, which they describe as similar to a superset of IBM's VDI, which they say has limited raster graphics support. A number of vendors are writing directly to the screen rather than the VDI to get better performance, including Lotus and Ashton-Tate. Microsoft's Windows uses Microsoft's Graphics Device Interface, a superset of Graphic Software Systems' VDI. Ashton Tate's development director said that because the EGA slows down the 8088, creating performance problems, the EGA's technical benefits almost require the 80286. A Microsoft software engineer said the basic 64 KB EGA forces a trade-off between resolution and color—a user can have either 4-color 640×350 or 16-color 640×200 resolution, recommending the 64KB piggyback board for good performance of 16 colors at 640×350 resolution. Historically, graphics has been viewed as a vertical market—charting or CAD/CAM. Graphics is moving from niche markets to an overall system technology incorporated in almost every type of application with the development of user interface technology.[112]
After four weeks of testing E-step samples of the 80286, Digital Research acknowledged that Intel corrected all documented 286 errata, but said there were still undocumented chip performance problems with the prerelease version of Concurrent DOS 286 running on the E-step. Intel said the approach Digital Research wished to take in emulating 8086 software in protected mode differed from the original specifications. Intel will make minor changes in the microcode that will allow Digital Research to run emulation mode much faster, incorporated into the E-2 step.[131]
September
Digital Research sidelines Concurrent DOS 4.1 into DOS Plus 1.x. The Philips :YES, a DOS Plus equipped Intel 80186-based computer to be produced and marketed in Austria, is announced.[132]
October
Microsoft releases MS-DOS 2.25, which added support for Korean Hangul characters. Many of the system utilities were made compatible with MS-DOS 3.0. This version was distributed in the Far East but was never shipped by OEMs in the United States and Europe.[66]
InfoWorld reported that business users were displaying a nearly insatiable demand for more disk storage capacity. A company was selling a disk system for the PC/AT that could hold 240 megabytes in one file, and many 40- and 80-megabyte disks were in use. However, there was a problem. DOS limited partitions to only 32 MB—the BPB's Total Sectors on the Volume field limit was 65,536 (216), and 16-bit addresses passed to interrupts 25h and 26h.[136] Many were surprised that IBM did not demolish the 32 MB barrier with PC-DOS 3.0 or 3.1. The most common way to resolve this problem was to treat large drives as if they were actually two or more drives. The drives are then called "logical"—or volume—drives, and work quite well so long as no one file is larger than 32 MB.[137]
Digital Research, in an effort to promote its stalled Concurrent PC-DOS operating system, modified the system to take advantage of the Rampage expanded memory specification. Concurrent PC-DOS XM is scheduled to be released in first quarter 1986, followed by a second quarter update compatible with PC-DOS 3.1's record and file locking scheme and file sharing schemes. Both the Lotus-Intel-Microsoft and AST expanded memory specifications enable users to address up to 8 MB of RAM.[138][139]
Microsoft releases MS-DOS 3.2. It adds support for 31⁄2-inch 720 KB floppy disk drives. A new device driver RAMDRIVE.SYS creates a virtual disk in either conventional memory, extended memory or Lotus-Intel-Microsoft Expanded Memory. However, the MS-DOS kernel does not take part in expanded memory manipulations and does not use expanded memory for its own purposes.[11] This is the first MS-DOS version Microsoft offered in a shrink-wrapped packaged version for smaller OEMs or system builders.[141]
InfoWorld reported that during the past year a growing number of generic, no-name PC compatibles gained support as legitimate alternatives to major manufacturers' systems. Components of clones have become such standard commodities that most feel that the generic machines achieve a high degree of compatibility. Although some dealers include a copy of MS-DOS with their generic micros, many small dealers do not. Usually users can buy copies of IBM's PC-DOS from authorized IBM dealers.[142]
IBM announces its reduced instruction set computer (RISC), the RT PC, with a 40 MB hard drive and a physical appearance virtually identical to the PC/AT. PC-DOS programs will run on RT PCs with an optional board containing an 80286 processor and a coprocessor program allowing users to switch between AIX and PC-DOS operations.[143]
February
Digital Research and IBM agreed to use Concurrent DOS 286 in versions of the PC/AT for point of sale in retail stores and other vertical applications. Concurrent DOS 286 will serve as the basis for IBM's 4680 operating system. Numerous IBM value-added resellers with medical, legal and other vertical application packages have shown interest in the product.[144]
March
IBM released the first components of its Token Ring local area network, and PC DOS 3.2, which supports token ring operations and adds support for 31⁄2-inch double-density 720 KB floppy disk drives. The Token Ring Network allows IBM PC users to share printers, files, and other devices. Supporting software includes the IBM Token Ring/PC Network Interconnect Program and the advanced program-to-program communications for the IBM PC (APP/PC). Some dealers carrying IBM's earlier networking product, the IBM PC Network, are waiting to gauge demand for the Token Ring Network before carrying the product.[145] PC DOS 3.2 supports the IBM PC Convertible, IBM's first computer to use 31⁄2-inch floppy disks, which will be available in May 1986.[146]
Apricot Computers pre-announces MS-DOS 4.0, the first multitasking version. Apricot will sell MS-DOS 4.0 to European customers as the controlling program for network servers that support a new family of Apricot microcomputers. Apricot will also offer MS-Net 2, a new version of Microsoft's LAN. Developers and industry insiders expect Microsoft to bypass that version in the United States in favor of a more powerful version, MS-DOS 5.0, which will access up to 16 MB of RAM.[147][148]
April
IBM announced the Expanded Memory Adapter (XMA) for the 3270 PC, which enables users to have multiple DOS sessions and a host session, or multiple host sessions and one DOS session. The XMA is not compatible with the Lotus-Intel-Microsoft specification, but uses a bank-switching technique that closely resembles AST's enhanced expanded memory specification (EEMS).[149]
May
While software makers debate a standard for memory-resident programs, two developers are racing to develop utilities that promise to help normally incompatible TSRs work together. The programs are Referee from Persoft Inc. and Borland's MOM (Memory Organization Manager).[150] Ultimately, users would rebel because they couldn't keep track of all the special conditions for each TSR. Many TSRs failed as products because dealing with the complexity was more trouble than the value delivered.[151]
August
IBM's retail PC market share slipped by 10 percent in the last year, and now accounts for less than half the PC-compatibles sold. For many, there seems to be no compelling reason to buy IBM anymore. In June, chief executive John F. Akers told analysts IBM would consider withdrawing from part of the PC market if it became too commodity-like.[152]
September
Compaq introduces the first Intel 80386-based computer, the Compaq Deskpro 386. It was the most powerful personal computer on the market. IBM had not yet ordered a single 386 chip from Intel.[25] Compaq President Rod Canion warned that if IBM doesn't respond with its own 80386-based machine within six months, the Deskpro 386 will become the industry's 32-bit personal computer standard. Two models were announced, Model 40 (40 MB hard drive) and Model 130 (130 MB). Both came with built-in support for Expanded memory.[153] The Deskpro 386 system memory board was expandable to 10 MB, but no operating system was yet available to take advantage of more than the 1 MB address space of the original IBM PC (except by creating RAM disks).[154] Compaq called their solution to the 32 MB partition limit enhanced disk, which was implemented with a custom Compaq version of FDISK that allowed creation of multiple MS-DOS partitions on a single hard drive, and the ENHDISK.SYS device driver installed into CONFIG.SYS to access those extra partitions.[155][156] Model 130's enhanced disk could hold four 32 MB partitions.
Microsoft demonstrates MS-DOS 4.0 and MS-Net 2.0 at a Paris trade show. They will be released simultaneously in the fourth quarter this year.[157] Apricot and SMT Goupil both plan to support the new software, but no U.S. vendor has yet opted to back the products.[158] However Microsoft president Jon Shirley said at least one contract is pending with a U.S. manufacturer. He said that MS-DOS 4.0 "doesn't move forward with the 286"—it does not replace Xenix or offer a completely multiuser DOS. It is intended for networks in which every workstation can process requests as a high-performance, non-dedicated file server with high level communications that need to do preemptive multitasking.[159]
November
Phar Lap Software introduced a DOS extender, 386/DOS-Extender, a software developer's tool that allows 32-bit mainframe-size application programs to run under MS-DOS 3.1 or 3.2 on any 80386-based IBM PC-compatible computer by taking advantage of the 80386's protected-mode memory capabilities.[160]
The Software Link demonstrated PC-MOS/386 at COMDEX. Release of the multiuser operating system that supports the 80386 virtual and protected modes is scheduled for February 1987.[161]
1987
January
Digital Research's new Flexible Automation Business Unit introduced its first product, the real-time operating systemFlexOS 286, a re-engineered version of Concurrent DOS 286 designed specifically for computer-integrated manufacturing.[162]
February
Digital Research launches Concurrent DOS 386, which runs up to four applications concurrently supporting up to 10 users on a system.[163][164]
April
Fox Software announced Foxbase 2.0 386, the first database to take full advantage of the 386's memory, by using the Phar Lap DOS extender program, which intercepts calls to DOS and automatically switches the system back to real mode for those functions. By tapping the chip's protected mode, the entire program can run in memory, eliminating disk access times and improving execution speed in some cases by a factor of 10. The program does not support multitasking, which must wait for advances in the operating system, so it is an interim solution.[165]
The IBM Personal System/2 line is released. Models range from the 8086-based Model 30, with Multicolor Graphics Array (MCGA) to the 80386-based Model 80, with 256 KB RAM Video Graphics Array (VGA).[166] They run on PC DOS 3.3 (the new protected mode multitasking Operating System/2 is announced, but not released until December). Version 3.3 added support for high density 31⁄2-inch 1.44 MB floppy disk drives, which IBM introduced in its 80286-based and higher PS/2 models, and introduced a partition type (0x05) for extended partitions, which could hold up to 23 logical drives. The Micro Channel architecture (MCA) bus is introduced—Models 50 and 60 use a 16-bit version, while Model 80 uses a version that supports 32-bit data and addressing.[167] The upgrade from DOS 3.2 to 3.3 was completely written by IBM, with no development effort on the part of Microsoft, who were working on "Advanced DOS 1.0". Soon after release, some users with non-IBM hardware reported hard drive problems. The MS-DOS version of 3.3 was still being tested by Microsoft.[168]
Fox Software ships Foxbase 2.0 386.[170] Phar Lap admits its 386/DOS Extender conflicts with TSR programs as well as Novell NetWare. Fox found Intelligent Graphics Corp.'s X-AM currently more reliable, and built an X-AM run-time version into Foxbase 2.0 386. The key to X-AM's performance is apparently its ability to switch from protected 386 mode to virtual 8086 mode.[171]
August
Compaq files a U.S. patent application for "software emulation of bank-switched memory using a virtual DOS monitor and paged memory management." Their invention uses 80386 paging hardware and virtual 8086 mode to emulate expanded memory using extended memory. The patent would be issued in 1990.[172]
Microsoft ships MS-DOS 3.3. It has the same feature set as the version IBM has been shipping since April.[173]
Lotus-Intel-Microsoft EMS 4.0 is announced. Key features include the capability to execute program code from expanded memory, including memory-resident programs; boosting the expanded memory ceiling from 8 to 32 megabytes; and the capability for multiple programs to use expanded memory at the same time. Quarterdeck introduced an update of QEMM supporting EMS 4.0. The new EMS is designed to eliminate "RAM cram," the overstuffing of conventional memory with TSR programs.[174]
October
International Computers Limited releases their OEM MS-DOS 4.1, a customized version that enabled users to run one application in foreground and an unlimited number of applications in background mode. It runs on an ISDN workstation.[175][176][177]
November
Compaq ships Compaq MS-DOS 3.31 with support for hard disk partitions over 32 MB, up to 512 MB. Partitions over 32 MB use a new partition type (0x06). Compaq dropped support for creating enhanced disks from their version of FDISK, while maintaining support for ENHDISK partitions created by previous versions.[178] This version introduced the Compaq Expanded Memory Manager (CEMM), which was the first so-called PC "memory manager" for Intel 80386 CPUs.
1988
January
Digital Research sidelines Concurrent DOS 6.0 as DR DOS 3.xx.
May
Digital Research releases DR DOS 3.31, supporting hard disk partitions up to 512 MB.
July
IBM ships IBM DOS 4.0. It adds an optional text-basedfile manager shell (DOSSHELL) with pull-down menus called by typing the F10 key, optional mouse support and a text-based user interface—an alternative to the command-line interface—which is a subset of OS/2 version 1.1's Presentation Manager. The DOS Shell could run in either text mode or graphics mode (on supported hardware), depending on how it was configured in the file DOSSHELL.BAT. Text mode is required to avoid incompatibilities (video conflicts) while running many popular TSR programs in graphics mode.[179] IBM DOS 4.0 supports Lotus-Intel-Microsoft EMS 4.0 on IBM's Expanded Memory Adapter, and is the first MS-DOS/PC DOS version that is "EMS-aware" and can use the EMS memory when it is available.[66] DOS 4 supports hard disk partitions over 32 MB, up to 1024 MB.[180] It also offers a hard drive installation program as an alternative to the procedure used in previous versions (FDISK, FORMAT, SYS, COPY), enhanced video/graphics support and improved error handling. The release was simultaneously announced by Microsoft, but no other OEMs had yet released it for their machines.[181] Because Microsoft already sells in Europe a multitasking version of DOS, which is called DOS 4.0, it is not clear if Microsoft will use a different version number for the new operating system.[182]
Microsoft released an extended memory specification, XMS, Version 2.0, implemented by the A20 handlerHIMEM.SYS in Windows/286. When run on 286- and 386-based systems, XMS can boost access to conventional memory by adding 64 KB (the high memory area) normally considered part of the extended-memory address range.[183]
September
IBM ships unannounced IBM DOS 4.01. Plagued with reports of bugs and incompatibilities, DOS 4.0 has been widely reported as being virtually unusable in its present state. IBM said that this was not a new version but a "maintenance diskette" to fix minor problems. However, early users said that the more serious incompatibilities resulting from a change in file structure have not been fixed by the upgrade.[184] IBM also released two enhanced PS/2 Model 30s that use the classic AT bus rather than the MCA bus, based on the 286 instead of 8086 processor, with VGA instead of MCGA graphics and 1.44 MB disk drives replacing 720 KB drives.[185]
Microsoft urged its OEMs to wait for a bug-fixing update of DOS 4.0 code before shipping their own versions. Microsoft released a DOS 4.0 Binary Adaption Kit - containing the operating system and utilities to help OEMs adapt it to their hardware - shortly after the mid-July announcement of DOS 4.0. Microsoft told manufacturers who distribute DOS under their own labels not to use that BAK and instead wait for the maintenance update, which contains several bug fixes, primarily for a problem with page frames involving EMS.[187]
Microsoft releases MS-DOS 4.01, including the user shell and EMS support.[190] Also, support for hard disk partitions up to 2 GB, and the SmartDrivedisk caching program.
1989
ROM-DOS, designed for embedded systems, is introduced by Datalight.
January
Developers Struggle With DOS Choices: As companies such as Lotus and Microsoft bring out improved but code-intensive versions of their programs, they're relying on bank-switching techniques or DOS extenders to make their programs run more efficiently under the 640K of RAM allowed by DOS. The choice is not a simple one. Each has its own set of assets and liabilities. But with OS/2 currently stalled in the market, there seems to be a future for alternatives. Microsoft has chosen bank switching for Excel and Windows, while Lotus has seriously looked at DOS extenders for its unreleased 1-2-3, Release 3.0.[191]
April
Compaq announced the availability of Compaq's MS-DOS version 4.01. Compaq continues to market their MS-DOS 3.31 as well. Compaq enhancements to MS-DOS 4.01 include Fastart, which speeds installation, and support for Lotus-Intel-Microsoft EMS 4.0.[192]
VESA adopts an extended-VGA mode displaying 800×600 resolution with 16 colors.[193]
June
Lotus ships Release 3.0 of its market leading spreadsheet 1-2-3, more than two years after the product was announced. The company spent $15 million bug testing 3.0,[194] which was translated into C[195] and uses extended memory by way of Rational Systems' Virtual Control Program Interface (VCPI)-compatible[196]DOS/16M 16-bit 80286 extender.[197]
July
InfoWorld reported that a year after its introduction, DOS 4.01's acceptance by users is slower than expected and lags behind the endorsements that greeted its predecessors. Users said they don't need its large disk partitions, can't afford to update their existing machines, and are wary of problems with how DOS 4.0 handles expanded memory. Also, no software developers have yet released applications that require the new version of DOS, which could force users to make the jump. Hardware vendors are taking longer than usual to adopt the new DOS for their hardware. Since other DOS updates have traditionally entered the workplace primarily accompanying the purchase of new PCs, this too hampered its adoption.[198]
September
InfoWorld reports that shadow RAM, a technique used by Chips and Technologies' NEAT chipset and AT/386 chipsets to speed performance by loading ROM BIOS functions into the upper memory area, has become a significant problem for users who want to run programs that use DOS extenders on 1-megabyte systems. The problem arises when products like Lotus 1-2-3, Release 3.0 try to use the memory that is tied up supporting shadow RAM. Invisible Software Inc. announced a $40 program called Invisible RAM which extends DOS memory from 640K to as high as 736K, allowing Release 3.0 users to load the program and have as much as 90 KB remaining for worksheet space. Or users could spend several hundred dollars for additional memory, with prices continuing their slow decline.[199]
VESA releases the VESA BIOS Extension 1.0, a specification to standardize a common software interface to Super VGA video adapters in order to provide simplified software application access to advanced VGA products.[201]
November
Compaq introduces the first EISA-based computers, the Deskpro 486 and the SystemPro, attempting to sway corporate accounts from minicomputers. NEC and Grid Systems Corporation also announced models incorporating the EISA bus.[202]
Responding to increasing industry confusion about the relative roles of Windows and OS/2, during the COMDEX IBM and Microsoft jointly issue a news release titled "IBM and Microsoft Expand Partnership; Set Future DOS and OS/2 Directions."[203] The majority of development resources will be applied to OS/2, with the intent to deliver a version that exploits the advanced capabilities of the 386 and i486 in 1990, with advanced features such as demand paging, the ability to run multiple DOS applications concurrently, and allow applications to exploit the 32-bit flat memory model; and enable OS/2 for 2 MB entry systems. DOS and Windows are recommended for systems with 1-2 MB of memory or fixed disk drives smaller than 30 MB.[204][205]
1990
April
Digital Research introduces DR DOS 5.0, a DOS clone which is a strong competitor to MS-DOS 3.3 and 4.01. It includes the MemoryMax "memory manager", the first memory management system to allow loading TSRs, device drivers and the operating system into upper memory blocks, and the operating system to be loaded into the high memory area. Also, ViewMAX, a graphical front end functionally equivalent to MS-DOS 4.01's graphics shell.[206] It supports hard disk partitions up to 512 MB.
Microsoft releases Windows 3.0, which would become the first widely successful version of Windows. Its File Manager became a popular alternative to the DOS Shell. Windows 3.0 runs on DOS 3.1 or higher.[209] This is the last version of Windows that could run on the IBM PC/XT (i.e., in real mode, which DOS runs in).
July
Digital Research ships DR DOS 5.0 to retailers.[210] This was the first non-IBM version of DOS sold directly to end-users. About 40 percent of the nearly 7 million Intel-based PCs shipped this year will be shipped without an operating system, spelling big bucks for retail DOS sales.[211]
September
IBM and Microsoft announce a realignment of their OS/2 development relationship.[212][213]
1991
March
Microsoft said that it had received a letter in June from the Federal Trade Commission advising it of an investigation of its competitive practices, limited to the November 1989 joint announcement with IBM regarding OS/2. Some industry executives think the investigation will lead the F.T.C. to a range of what they consider to be anti-competitive practices by Microsoft. Digital Research said that after it introduced its DR DOS version 5.0 in April 1990, Microsoft immediately announced a version of MS-DOS, with "amazing similarity," which has yet to appear.[214]
AddStor Inc. announces the first version of SuperStor on-the-fly disk compression software.[215]
May
IBM DOS 5 is released. It featured the moving of the DOS kernel and command.com into the high memory area.
June
Microsoft releases MS-DOS 5.0. The full-screen MS-DOS Editor is added to succeed Edlin. It adds undelete and unformat utilities, and task swapping. GW-BASIC is replaced with QBasic.[216]
July
Novell announces that it intends to acquire Digital Research.[217] Completion of the merger is expected in October. Both companies intend to augment DR DOS to handle basic Novell NetWare functions.[218]
Microsoft says they will no longer call a new operating system they are working on OS/2 3.0—the new operating system will be named Windows NT (New Technology), which will not be able to run programs written for OS/2. Windows NT will be geared for more powerful computers and workstations, while a low-end version of Windows will run on top of MS-DOS.[219]
September
Digital Research releases DR DOS 6.0 with AddStor's SuperStor disk compression.
November
Several companies announce or demonstrate proprietary local-bus graphics technologies at COMDEX. VESA is hoping to create a local-bus standard.[220]
Microsoft introduces MS-DOS 6.0, including DoubleSpace disk compression.
Novell tried to dampen Microsoft's DOS 6 launch with the announcement that the new Novell DOS 7, based on the integration of DR DOS 6.0 and Novell's NetWare Lite, will include advances such as peer-to-peer networking that Microsoft left out of its latest release.[222]
June
IBM releases PC DOS 6.1.
August
A month after the Federal Trade Commission deadlocks for the second time with a 2-2 vote on whether to take action against Microsoft, the Justice Department officially notified Microsoft that it was proceeding with the case, ending the FTC's three-year investigation.[203]
November
Microsoft replaces MS-DOS 6.0 with MS-DOS 6.2, leapfrogging IBM's PC-DOS 6.1.[223]
Microsoft releases MS-DOS 6.21, removing DoubleSpace disk compression.
April
IBM releases PC DOS 6.3, including SuperStor/DS, a special version of AddStor's disk compression utility.
June
Microsoft releases MS-DOS 6.22, bringing back disk compression under the name DriveSpace.
PD-DOS, the open-source project later known as FreeDOS, is announced.[224]
1995
April
IBM releases PC DOS 7.0, replacing SuperStor/DS with Stac Electronics' Stacker, Version 4.02. This is the first DOS to feature a command-line calculator, a program to load device drivers from the command line, REXX language support, and a viewer that can open help files other than its own (OS/2 INF style).[225]
June
ECMA adopts the 2nd edition of standard ECMA-107, Volume and File Structure of Disk Cartridges for Information Interchange, standardizing FAT16 support for zip drives and optical discs.[140]
July
PTS-DOS 7.0 is released.
1995–2000: Windows 9x era
1995
August
Windows 95 is released, launching the Windows 9x era. It comes with an MS-DOS -like bootloader reporting DOS version 7.0.
Caldera, Inc., releases M.R.S. open-source kit of OpenDOS 7.01 by Caldera UK, Ltd on 1997-05-05. This is also the first DOS to be released on a CD-ROM.[226]
December
Caldera, Inc., releases DR-OpenDOS 7.02 by Caldera UK, Ltd.
IBM releases PC DOS 2000, which has minor Y2K fixes for older computers which do not properly handle the century rollover. It also supports the Euro currency symbol.
Microsoft Windows Me is released, identifying itself as MS-DOS 8.0. It was the last version of MS-DOS, as future versions of Windows were based on the Windows NT architecture.
^US trademark, registration #1036693, serial #73064349. Word mark: FLIPPY, First use: July 1974, Filing date: Sept. 29, 1975, Registration date: March 30, 1976. United States Patent and Trademark Office (uspto.gov) Trademark Electronic Search System (TESS)
^ abcdefghijklmnopqrsDuncan, Ray (1988). The MS-DOS Encyclopedia, Microsoft Press. ISBN 1-55615-049-0.
^ abcFreiberger & Swaine (2000). Fire in the Valley: The Making of The Personal Computer (Second Edition), McGraw Hill, ISBN 0-07-135892-7.
^Digital Research (1984): Concurrent CP/M ships early in response to team effort. Digital Dialogue - Employee Newsletter of Digital Research Inc., Volume 3, Number 1, p. 1 ([4]).
^ abEdward Foster. Super DOS awaits new 80286 - Concurrent DOS 286 - delayed until Intel upgrades chip - offers Xenix's power and IBM PC compatibility. InfoWorld Media Group, InfoWorld, Volume 7, No. 19, 1985-05-13, ISSN 0199-6649, pages 17-18, ([11]).
^PC DOS 7 beats its disappearing competitors, InfoWorld, April 10, 1995
^Caldera. Caldera releases OpenDOS kernel source to the Internet - Distribution of OpenDOS kernel unprecedented in Computer Industry. Press announcement as of 1997-04-30 ([15]).
