Also presented is a timeline of events in the history of the 8-bit 8080-based and 16-bit x86-based CP/M operating systems from 1974 to 2014, as well as the hardware and software developments from 1973 to 1995 which formed the foundation for the initial version and subsequent enhanced versions of these operating systems.
OEM adaptation kits (OAKs) – all Microsoft releases before version 3.2 were OAKs only
Shrink wrap packaged product for smaller OEMs (system builders) – starting with MS-DOS 3.2 in 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
Free download – starting with OpenDOS 7.01 in 1997, followed by FreeDOS alpha 0.05 in 1998 (FreeDOS project was announced in 1994)
Some 200 Intel customers have used the MCS-4 and MCS-8microcomputerchip sets introduced in 1971 and 1972 in more than 60 applications, including: point-of-sale terminals; typewriter-sized general-purpose data processing machines that tabulate accounts, type invoices, and write checks and personalized form letters; process controllers for automatic bottle-loading machines; and a front-end processor in a dial-up communications controller. Microcomputers are increasingly used in systems too small or slow to warrant use of minicomputers. Intel's support for system-building includes SIM4-01 and SIM8-01 prototyping boards that form functioning micro computers, programmable read-only memory (PROM) programmers, and a PROM-based assembler.[1] Intel introduces the 2048-bit (256-byte) erasable 1702A EPROM chip. It can be programmed in two minutes using Intel's punched paper tape-actuated programmer, and erased as often as needed by shining an ultraviolet light through a transparent quartz cap on the package.[2] Intel claims its first two microcomputers command about 99% of the market which Fairchild Semiconductor, National Semiconductor and Rockwell International have joined.[3]
IBM introduces the IBM 3740 data entry system. It uses IBM's first read/write diskette, a single-sided 8-inch-diameter "memory disk"—a new recording medium to replace punched cards.[4] Each diskette can hold as much data as 3,000 standard 80-column punched cards.[5]See also: History of the floppy disk
In July, Intel debuts its model 2107 4,096-bit (4-kilobit) n-MOS RAM, which competes with 4kb RAMs from TI, Mostek and Microsystems International. It's slow compared with 1kb RAMs such as the p-MOS1103 and the n-MOS 2105. Nearly all new computers, regardless of size, now come with a semiconductor memory or a choice between semiconductors and cores.[15][16]
Intel releases the 8-bit 8080 (cost $360, compared to the dominant and far more powerful IBM System/360's millions), which has a 16-bit address bus that can address 216 (65,536) memory locations, or 64 KB of memory. The 8080's enhanced stack makes self-hosted high level language development feasible.[18]
Lacking an affordable reader for 16-channel paper tapes, the Traf-O-Data partners turn to a local inventor. At a demo for the King County Engineering Department, their contraption malfunctioned, prompting Gates to bite the bullet and spend about $3,400 for the more reliable Enviro-Labs GS-311 tape reader.[17][21]
Kildall writes CP/M, a simple "Control Program/Monitor" for an Intel 8080-based Intellec 8,[22] to test out his updated PL/M compiler for the 8080. CP/M, written in PL/M, was finished months before the hardware to run it on was completed, by using a PDP-10 to simulate the 8080. CP/M runs in approximately 31⁄2kilobytes (KB) of memory.[23] Convinced that magnetic-disk storage would make the Intellec 8 more efficient, Kildall interfaced the computer with an 8-inch Shugart Associatesfloppy disk drive using a custom built floppy disk controller. Kildall's friend John Torode developed the controller hardware while Kildall worked on the disk operating systemsoftware.[24] Believing, along with Intel's designers, that the microprocessor would run embedded systems such as digital watches, they market their hardware and software together—not as a microcomputer, but as a development system, used for programming Intel 1602A PROM or erasable 1702A EPROM chips which are plugged into a socket on the Intellec 8's front panel.[25][26][27]
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.[37]
1976
IBM introduces more hardware components for its 3600 finance communication system, including the first double-sided (dual head) floppy drive.[38] ITC adjusts Flippy (now a registered trademark) production to accommodate the new drive.[39]
IMSAI ships a lot of disk subsystems, promising that an operating system (OS) would follow;[33][40] 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,[32][33] e.g. Rob Barnaby for the IMSAI VDP-80 in 1977.[35] 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 advocated sale of CP/M to the general public. An ad runs in the December Byte as well.[41] Demand for the diskettes was slow at first.[23][24][32]
Shugart introduces the (single-sided) minifloppy, the first 51⁄4-inch floppy drive.[42]
1977
Torode's Digital Systems runs an ad in Byte for its Altair/IMSAI (S-100) bus floppy disk system.[43]
IMSAI marketing director Seymour I. Rubinstein paid Kildall $25,000 for the right to run CP/M version 1.3, which eventually evolved into IMDOS, on IMSAI 8080 computers.[33][44] 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.[45][46] Eventually IBM, Shugart and other manufacturers became licensees of Tandon's patent.[47][48] Later, Shugart introduces their double-sided, double-headed, double density minifloppy drive.[49]
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.[50]: 111
CP/M version 1.4, now priced at $100, is released.[51][10]
IEEE proposes an S-100 standard, introducing a 16-bit data bus to the S-100.[52]
Rubinstein founds MicroPro International. Its WordStar word processor application would become a de facto standard.
Paterson, with his working two-card prototype boardset installed in a Cromemco Z-2 box, drives to Microsoft to try it with Microsoft's Standalone Disk BASIC-86—a version of BASIC with a rudimentary built-in operating system—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.[17][44]
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 operating system (later renamed to MIDAS), which used a variant of Standalone BASIC's 8-bit File Allocation Table (FAT) file system.[17][24][44][54]
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.[55] The 8088 uses lower cost 8-bit RAM.[56]
November
Seattle Computer Products ships its first 8086 card. Standalone Microsoft BASIC is the only major software product that runs on it.[17][57]
Onyx Systems and Intelligent Business Machines Corp. announce that CP/M 2.0 is available for their systems.[58]
1980
January
Omnix, advertised as a CP/M-compatible Unix-like operating system for Z80-based microcomputers, is released by Yourdon. It reportedly took over 50 KB of memory by itself and required some sort of bank-switching or extended address scheme to run any programs. Yourdon later withdrew the product due to software bugs.[59][60][61][62][63]
March
CP/M 2.1 is released, fixing bugs in version 2.0. MP/M, the multitasking, multi-user version of CP/M, is just a "shell" that fits around CP/M 2.1.[61]
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, and concerns about CP/M's shortcomings.[57]
Microsoft introduces the Z-80 SoftCard, which lets Apple users run CP/M.[64]
IBM first contacts Microsoft to look the company over. Their secret Project Chess needs both programming languages and an operating system.
August
Paterson's operating system, which he calls QDOS 0.10 ("Quick and Dirty Operating System"), ships.[57] It's crammed into 6 KB of code.[21] Seattle Computer Products runs an ad in Byte marketing it as 86-DOS for $95.[66] Seattle Computer contacts Microsoft about adapting Microsoft BASIC for the new operating system, proposing a cross-licensing arrangement.[17]
Microsoft announces Xenix, a port of Version 7 Unix to x86 computers, saying that it will prevent a 16-bit software crisis. Xenix will also be available for the PDP-11 as early as October; Motorola 68000 and Zilog Z8000 versions are also coming. Interest in Unix as "the next CP/M" resulted in the creation of several Unix-like operating systems, including an Onyx Systems version for the Z8000.[62][67][68]
September
Allen negotiates an agreement with Seattle Computer for a non-exclusive 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.[17]
October
Digital Research announces CP/M-86 for Intel 8086/8088 microcomputers. The file format of CP/M, Release 2, was retained for compatibility.[69]
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.[17]
Microsoft and Seattle Computer formally sign their agreement. Exhibit "A" of the agreement detailed extended 86-DOS features to be developed by Seattle Computer, including "Directory expanded to include date."[44][70]
Digital Research ships CP/M-86 on January 23.[32][71] 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. Intel's PL/M-86 was used to generate CP/M-86, which is basically the same as the 8-bit version, with the addition of file system enhancements as well as memory management.[72][73]
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.[24] An Intellec ICE-88 in-circuit emulator expedited the debugging.[21][74]
April
Paterson finishes, and Seattle Computer releases, 86-DOS 1.0[57][75] – presumably completing the requirements specified in Exhibit "A" of the Microsoft agreement.
May
Paterson leaves Seattle Computer Products for Microsoft and joins O'Rear to help finish adapting 86-DOS to IBM's prototype hardware.[44]
June
Lifeboat Associates, the leading independent distributor of CP/M and CP/M software, offers Seattle Computer Products $200,000[17] or $250,000[44] for 86-DOS, to make it Lifeboat's 16-bit standard.
July
Kildall, angry after seeing the API for IBM's secret computer, that IBM had let selected programmers have, meets with IBM and agrees not to sue IBM for CP/M copyright infringement; IBM agrees to market CP/M-86 alongside DOS, but could not agree to set a price—according to Kildall's attorney, "They told us they feared it would be a violation of antitrust laws." Immediately afterwards, IBM sent their prototype machine to Kildall so that CP/M-86 could be installed. Digital Research hired consultant Andy Johnson-Laird to customize CP/M-86 for IBM's computer, and Johnson-Laird quickly discovered O'Rear's name in the boot sector of IBM's floppy. Johnson-Laird said that Kildall "went ashen" when he saw that.[32][76][77][78][79]
On July 27, Microsoft buys all rights to 86-DOS from Seattle Computer Products, initially for a further $50,000 and favorable licenses back from Microsoft.[57][80] 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, the DOS-BIOS 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 abilities 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 clusters, which are one-sector in length. Because an 8-bit FAT can't support over 300 clusters, Paterson implemented a new 12-bit FAT, which would be called FAT12.[D] 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; a Program Segment Prefix is built when they are loaded into memory. The third kind of command processing file is the batch file. AUTOEXEC.BAT is checked for, and executed by COMMAND.COM at start-up.[83] 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.[24] The video controller, floppy disk controller, further memory, serial and parallel ports are added via up to five 8-bit ISAexpansion cards. Delivery of the computer is scheduled for October.[86]
1981
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.[87]
Lifeboat Associates, having lost its bid for rights to 86-DOS, announced that it will market Microsoft's MS-DOS under the name Software Bus-86 (SB-86).[17][88] Their line of trademarked Software Bus products included SB-80, Lifeboat's version of CP/M.[24]
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.[89] 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.[87][90]
Microsoft signs its first major DOS deal at COMDEX, with Chuck Peddle's new startup company Sirius Systems Technology, whose Victor 9000 was among the first of many 16-bit computers similar to and better than the IBM PC—but incompatible with it. Earlier, Microsoft signed its first DOS customer, Cleveland's Tecmar, but they put their 8086 machine on the back burner when they became a major player in the PC peripherals business.[17][91][92]
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.[23][93] 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.[94]
A Seattle Computer ad in InfoWorld offers an 8086 system with 86-DOS under its new name MS-DOS, noting that MS-DOS is "also called 86-DOS, IBM PC-DOS, Lifeboat SB-86".[95] Seattle Computer was the first company to offer the product under the MS-DOS name.[17]
1982
January
The U.S. Justice Department drops its 13-year case against IBM, that had sought to break up the firm 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.[96]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.[97]
Corvus Systems released interfaces to make its line of Winchester disk drive systems and local area network (LAN) 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.[98] The Corvus Omninet local network scheme can spread the cost of a hard disk drive among several users.[99] Omninet, which uses twisted pair cabling, is billed as a low-cost alternative to more costly coaxial-based networks such as Ethernet.[100]
March
Paterson finishes work on the first DOS upgrade, quits Microsoft and returns to work for Seattle Computer.[44]
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 exploit 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.[101]
On April 5, 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 (when first loaded out of the box, it displays the date 2/10/82, perhaps suggesting when it was finished). For about six 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.[102] 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.[103][104] 96 percent of the early PC owners chose DOS over CP/M or the p-System.[105]
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.[106]
Microsoft runs an ad in InfoWorld promoting MS-DOS to OEMs.[107]
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 the reserved field to 10 bytes.[83]Timestamping on files is useful for incremental backup with the Corvus hard disk. Based on MS-DOS 1.24[57] as of March 1982, 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.[24] 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. Also available is Microsoft's Macro Assembler. A typical PC with 320 KB of disk storage, keyboard, printer, monochrome display and MDA costs $3695.[111][112][113][114]
June
Microsoft releases MS-DOS 1.25 (equivalent to PC DOS 1.1; system files are IO.SYS and MSDOS.SYS; GW-BASIC is an entirely disk-based substitute for BASICA).[115]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.[24]
Peter Norton, a pioneer in the DOS-based utility software industry, advertises his utilities in the third issue of PC Magazine.[116] Norton sells programs providing disk editor functionality and an UNERASE program which solved "a common problem to which there was no readily available solution."[117] 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. Initially the programs were sold separately, but by October Norton offered them as a package called The Norton Utilities.[118] Earlier, an UNERASE program to restore files accidentally deleted by CP/M's ERAse command was marketed for CP/M-based systems by MicroDaSys.[119]
1982
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.[120]
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.[127]
Also at COMDEX, Compaq announces the first IBM PC compatible portable computer, the Compaq Portable. 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.[129] Its operating system was called COMPAQ-DOS,[130] adding to the confusing host of names for MS-DOS. Microsoft finally insisted that their operating system be called MS-DOS, and eventually everyone but IBM complied.[24] A June 1983 PC Magazine product review said "the Compaq comes with Microsoft's MS-DOS 1.1 operating system, which is almost identical to PC-DOS 1.1".[131] Having already discovered differences between MS-DOS and PC DOS, Compaq continued internally developing COMPAQ-DOS to increase compatibility with the latter.[130]
1983
January
Lotus Development Corp. releases Lotus 1-2-3, which would become the IBM PC's first "killer application", making the PC as VisiCalc made the Apple II and WordStar made the CP/M machines. 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 (the other was Flight Simulator, for which Bruce Artwick wrote his own purposive built-in OS). The Compaq was the only non-IBM machine that could run 1-2-3.[17]
February
IBM announces a new color display, the IBM 5153 Model 1 for the PC, for presentation of CGA-resolution business data and graphics.[132] Home users can connect a television using a frequency modulator.[85]
At the CP/M'83 show in San Francisco, Digital Research announces that it will market a retail version of CP/M-86 for the IBM PC for $60, which includes a print spooler and GSX, which was formerly sold separately.[133][134]
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 sectors (179,712 bytes) for data on single-sided disks and 354 clusters (362,496 bytes)[E] on double-sided disks.
In addition to Microsoft's new commands in MS-DOS 2.0 (above), IBM adds more including FDISK, the fixed disk[F] 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 10,618,880 bytes[G] of raw space.
The DOS partition on the fixed disk continues to use the FAT12 format, but with adaptations to support the much larger size of the fixed disk partition compared to floppy disks. Space in the user data area of the disk is allocated in clusters which are fixed at 8 sectors each. With DOS the only partition, the combined overhead is 50 sectors[H] leaving 10,592,256 bytes[I] for user data.[83] 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.[24][135][136][137] 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.[21] Peter Norton found many problems with the release. Interrupts 25h and 26h, which read or write complete sectors, redefined their rules for absolute sector addressing, "sabotaging" programs using these services.[83][138] The XT motherboard uses 64-kilobit DIP chips, supporting up to 256 KB on board. With 384 KB on expansion cards, users could officially reach the 640 KB barrier of conventional memory.[139] The power supply capacity was doubled to about 130 watts, to accommodate the hard drive.[140]
1983
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.[141] CP/M 3 was available on the last generation of 8-bit computers.
Responding to VisiCorp and other competitors working on operating environments, Microsoft's Rao Remala assembles the "Interface Manager" demo which consisted of a screen filled with overlapping windows apparently running programs that really didn't do anything. At Microsoft it became known as the "smoke-and-mirrors" demo.[17]
May
Fujitsu Microelectronics releases the first 256-kilobit DRAM chip, and its Micro 16s computer. A memory board using the 256-kb chips that allows the Micro 16s to store a full megabyte will be made available later this year.[142][143][144]
At the Spring COMDEX in Atlanta, Microsoft introduces the Microsoft Mouse, priced at $195. It comes in either a bus or serial version, with the Multi-Tool[J]Notepad, a mouse-based text editor written by Richard Brodie.[147] Microsoft also introduces Multi-Tool Word, designed by Charles Simonyi to work with the mouse.[148][149] Most watching Simonyi's demonstration had never heard of a mouse. As many as eight documents could be edited at the same time in so-called windows.[44]
June
Microsoft releases the Microsoft Mouse. Initial sales were modest, as there was little you could do with it except run the demonstration programs included in the box (a tutorial, practice app and Notepad) or program interfaces to it.[17] The mouse began shipping in July.[150]
July
Wang Laboratories announced it had developed the Wang SIMM (single in-line memory module), which integrates nine 64-kilobit RAM chips into a .75 by 3-inch space. Wang said the SIMM could lessen the need for 256-kilobit chips which have just started production and are relatively costly, since the SIMM is denser than 256 kb and is available now. The SIMM is being offered to interested semiconductor makers, and National Semiconductor and Zenith Microcircuits have committed to manufacture 64 KB (9 × 64 kb) RAM modules based on the SIMM design. The SIMM's 30 pins are inserted into a plastic chip carrier rather than the gold-plated leadless ceramic chip carrier. Added address pins were included to enable upgrading, and Wang said it will soon assemble 256-kb components around SIMM. National Semiconductor plans to market a modified SIMM with surface-mounted chips in early 1984.[151][152]
October
IBM releases the IBM 3270 PC, an IBM PC/XT containing added 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.[24][115][153] With the help of Kazuhiko Nishi, leader of ASCII Microsoft, Microsoft arrived early in Japan.[17]
The Philips/Sony "Yellow Book" sets rules for storing data on CD-ROM, but omits mention of any logical structure for files and directories.[154]
1983
November
The IBM PCjr is announced.[155] It had half-height 51⁄4-inch disk drives and ran PC DOS 2.1.[156] 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.[129] International modifications in MS-DOS 2.01 were not included because IBM did not want them. PCjr ships first quarter 1984 in limited supply.
Microsoft Word ships. On the suggestion of Rowland Hanson, who also convinced Gates to change the name "Interface Manager" to "Windows", the Multi-Tool name was killed. PC World bound an envelope containing a Word demonstration disk inside its pages.[17][157][158][159]
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.[25][160][161][162]
Less than two weeks after VisiCorp announced the release of Visi On (see below), in New York on November 10, 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.[17][163][164]
December
Visi On, the first graphical user interface-based operating environment for the PC—generally viewed as VisiCorp's answer to Apple's Lisa—ships.[165] It runs on top of DOS 2.0 and requires at least 512 KB RAM and a 5 MB hard drive, a Mouse Systems-compatible mouse and CGA. It does not make use of color[166]—it uses black-and-white graphics at 640×200 resolution. Although it was highly hyped in 1982 and 1983, Visi On never caught on—it was painfully slow and overpriced ($1765 with the mouse, a spreadsheet similar to VisiCalc, and word-processing and graphics programs).[167][168][169] Few users had mice and hard disks, and many balked at paying $2500 or more to add them to their computers.[170]
1984
January
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.[171]
The Macintosh 128K, a milestone computer designed around a graphical user interface, is introduced. It would be several years before the PC platform had graphics as a standard feature, and not until 1990 would PC graphics "really work".[30][172]
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.[173]
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.[24] It was shipped by every major
