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82-549: The command is available in the operating systems Digital Research CP/M , MP/M , Cromemco CDOS , MetaComCo TRIPOS , DOS , IBM OS/2 , Microsoft Windows , ReactOS , SymbOS , and DexOS. Multics includes a rename command to rename a directory entry. It can be contracted to rn . Stratus OpenVOS , DEC RT-11 , OS/8 , RSX-11 , Intel ISIS-II , iRMX 86 , TOPS-20 , Zilog Z80-RIO , TSC FLEX , Microware OS-9 , DR FlexOS , IBM/ Toshiba 4690 OS , HP MPE/iX , THEOS/OASIS , and OpenVMS also provide

164-413: A ROM firmware chip) loads the operating system from the disk in drive A: . By modern standards CP/M is primitive, owing to the extreme constraints on program size. With version 1.0 there is no provision for detecting a changed disk. If a user changes disks without manually rereading the disk directory the system writes on the new disk using the old disk's directory information, ruining the data stored on

246-464: A competitor in the spreadsheet market in the MS-DOS world. AutoCAD , a CAD application from Autodesk debuted on CP/M. A host of compilers and interpreters for popular programming languages of the time (such as BASIC , Borland 's Turbo Pascal , FORTRAN and even PL/I ) were available, among them several of the earliest Microsoft products. CP/M software often came with installers that adapted it to

328-528: A corporation change-of-name filing to Digital Research, Inc. By September 1981, Digital Research had sold more than 250,000 CP/M licenses; InfoWorld stated that the actual market was likely larger because of sublicenses. Many different companies produced CP/M-based computers for many different markets; the magazine stated that "CP/M is well on its way to establishing itself as the small-computer operating system". The companies chose to support CP/M because of its large library of software. The Xerox 820 ran

410-773: A directory except those marked with the SYS attribute), DIRSYS / DIRS (list files marked with the SYS attribute in the directory), ERASE / ERA (delete a file), RENAME / REN (rename a file), TYPE / TYP (display contents of an ASCII character file), and USER / USE (change user number) as built-in commands: CP/M 3 allows the user to abbreviate the built-in commands. Transient commands in CP/M 3 include COPYSYS , DATE , DEVICE , DUMP , ED , GET , HELP , HEXCOM , INITDIR , LINK , MAC , PIP, PUT , RMAC , SET , SETDEF , SHOW , SID , SUBMIT , and XREF . The Basic Disk Operating System, or BDOS, provides access to such operations as opening

492-460: A directory or ERA to delete a file) or loads and starts an executable file of the given name (transient commands such as PIP.COM to copy files or STAT.COM to show various file and system information). Third-party applications for CP/M are also essentially transient commands. The BDOS, CCP and standard transient commands are the same in all installations of a particular revision of CP/M, but the BIOS portion

574-449: A dozen different CP/M systems, plus two generic versions. The operating system was described as a " software bus ", allowing multiple programs to interact with different hardware in a standardized way. Programs written for CP/M were typically portable among different machines, usually requiring only the specification of the escape sequences for control of the screen and printer. This portability made CP/M popular, and much more software

656-429: A file, output to the console, or printing. Application programs load processor registers with a function code for the operation, and addresses for parameters or memory buffers , and call a fixed address in memory. Since the address is the same independent of the amount of memory in the system, application programs run the same way for any type or configuration of hardware. The Basic Input Output System or BIOS, provides

738-518: A parallel development Digital Research also produced a selection of programming language compilers and interpreters for their OS-supported platforms, including C , Pascal , COBOL , FORTRAN , PL/I , PL/M , CBASIC , BASIC , and Logo . Digital Research developed CP/M-86 as an alternative to MS-DOS and it was made available through IBM in early 1982. The company later created an MS-DOS clone with advanced features called DR DOS , which pressured Microsoft to further improve its own DOS. At

820-469: A part of the Amateur Computer Club of New Jersey . ZCPR2 was released on 14 February 1983. It was released as a set of ten disks from SIG/M. ZCPR2 was upgraded to 2.3, and also was released in 8080 code, permitting the use of ZCPR2 on 8080 and 8085 systems. ZCPR3 was released on 14 July 1984, as a set of nine disks from SIG/M. The code for ZCPR3 could also be compiled (with reduced features) for

902-508: A prevailing naming scheme of the time, as in Kildall's PL/M language, and Prime Computer's PL/P ( Programming Language for Prime ), both suggesting IBM's PL/I ; and IBM's CP/CMS operating system, which Kildall had used when working at the NPS. This renaming of CP/M was part of a larger effort by Kildall and his wife with business partner, Dorothy McEwen to convert Kildall's personal project of CP/M and

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984-508: A program was not standardized, so that there is no single option character that differentiated options from file names. Different programs can and do use different characters. The CP/M Console Command Processor includes DIR , ERA , REN , SAVE , TYPE , and USER as built-in commands. Transient commands in CP/M include ASM , DDT , DUMP , ED , LOAD , MOVCPM  [ pl ] , PIP , STAT , SUBMIT , and SYSGEN . CP/M Plus (CP/M Version 3) includes DIR (display list of files from

1066-798: A relocating assembler and linker. CP/M 3 was available for the last generation of 8-bit computers, notably the Amstrad PCW, the Amstrad CPC , the ZX Spectrum +3 , the Commodore 128 , MSX machines and the Radio Shack TRS-80 Model 4 . There were versions of CP/M for some 16-bit CPUs as well. The first version in the 16-bit family was CP/M-86 for the Intel 8086 in November 1981. Kathryn Strutynski

1148-404: A single-user version featuring virtual consoles from which applications could be launched to run concurrently. In May 1983 Digital Research announced that it would offer PC DOS versions of all of its languages and utilities. It remained influential, with US$ 45 million in 1983 sales making Digital Research the fourth-largest microcomputer software company. Admitting that it had "lost"

1230-530: A user-installed overlay containing all the code required to access a particular machine's serial port. WordStar, one of the first widely used word processors , and dBase , an early and popular database program for microcomputers, were originally written for CP/M. Two early outliners , KAMAS (Knowledge and Mind Amplification System) and its cut-down successor Out-Think (without programming facilities and retooled for 8080/V20 compatibility) were also written for CP/M, though later rewritten for MS-DOS. Turbo Pascal ,

1312-540: A wide variety of computers. The source code for BASIC programs was easily accessible, and most forms of copy protection were ineffective on the operating system. A Kaypro II owner, for example, would obtain software on Xerox 820 format, then copy it to and run it from Kaypro-format disks. The lack of standardized graphics support limited video games , but various character and text-based games were ported , such as Telengard , Gorillas , Hamurabi , Lunar Lander , along with early interactive fiction including

1394-418: Is a disk operating system and its purpose is to organize files on a magnetic storage medium, and to load and run programs stored on a disk. Initially confined to single-tasking on 8-bit processors and no more than 64 kilobytes of memory, later versions of CP/M added multi-user variations and were migrated to 16-bit processors . The combination of CP/M and S-100 bus computers became an early standard in

1476-451: Is always adapted to the particular hardware. Adding memory to a computer, for example, means that the CP/M system must be reinstalled to allow transient programs to use the additional memory space. A utility program (MOVCPM) is provided with system distribution that allows relocating the object code to different memory areas. The utility program adjusts the addresses in absolute jump and subroutine call instructions to new addresses required by

1558-473: The rename command which in some cases can be contracted to ren . The rename command is supported by Tim Paterson 's SCP 86-DOS . On MS-DOS , the command is available in versions 1 and later. DR DOS 6.0 also includes an implementation of the ren and rename commands. In Windows PowerShell , ren is a predefined command alias for the Rename-Item Cmdlet which basically serves

1640-530: The Zork series and Colossal Cave Adventure . Text adventure specialist Infocom was one of the few publishers to consistently release their games in CP/M format. Lifeboat Associates started collecting and distributing user-written "free" software. One of the first was XMODEM , which allowed reliable file transfers via modem and phone line. Another program native to CP/M was the outline processor KAMAS. The read/write memory between address 0100 hexadecimal and

1722-578: The PDP-11 and OS/8 for the PDP-8 . Commands take the form of a keyword followed by a list of parameters separated by spaces or special characters. Similar to a Unix shell builtin , if an internal command is recognized, it is carried out by the CCP itself. Otherwise it attempts to find an executable file on the currently logged disk drive and (in later versions) user area, loads it, and passes it any additional parameters from

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1804-518: The TOPS-10 operating system of the DECsystem-10 mainframe computer , which Kildall had used as a development environment. An early outside licensee of CP/M was Gnat Computers , an early microcomputer developer out of San Diego, California . In 1977, the company was granted the license to use CP/M 1.0 for any micro they desired for $ 90. Within the year, demand for CP/M was so high that Digital Research

1886-483: The extension .COM on disk. The BIOS directly controls hardware components other than the CPU and main memory. It contains functions such as character input and output and the reading and writing of disk sectors. The BDOS implements the CP/M file system and some input/output abstractions (such as redirection) on top of the BIOS. The CCP takes user commands and either executes them directly (internal commands such as DIR to show

1968-441: The 7-bit boundary. In the 8-bit versions, while running, the CP/M operating system loaded into memory has three components: The BIOS and BDOS are memory-resident, while the CCP is memory-resident unless overwritten by an application, in which case it is automatically reloaded after the application finished running. A number of transient commands for standard utilities are also provided. The transient commands reside in files with

2050-429: The 8080 I/O address space. All of these variations in the hardware are concealed from other modules of the system by use of the BIOS, which uses standard entry points for the services required to run CP/M such as character I/O or accessing a disk block. Since support for serial communication to a modem is very rudimentary in the BIOS or may be absent altogether, it is common practice for CP/M programs that use modems to have

2132-421: The 8080 and would run on systems that did not have the requisite Z80 microprocessor. Features of ZCPR as of version 3 included shells, aliases, I/O redirection, flow control, named directories, search paths, custom menus, passwords, and online help. In January 1987, Richard Conn stopped developing ZCPR, and Echelon asked Jay Sage (who already had a privately enhanced ZCPR 3.1) to continue work on it. Thus, ZCPR 3.3

2214-434: The 8088 software market but hoped to succeed with the Intel 80286 and Motorola 68000 , by 1984 the company formed a partnership with AT&T Corporation to develop software for Unix System V and sell its own and third-party products in retail stores. Jerry Pournelle warned later that year, however, that "Many people of stature seem to have left or are leaving Digital Research. DR had better get its act together." In

2296-429: The CP/M base included Robert "Bob" Silberstein and David "Dave" K. Brown. CP/M originally stood for "Control Program/Monitor", a name which implies a resident monitor —a primitive precursor to the operating system. However, during the conversion of CP/M to a commercial product, trademark registration documents filed in November 1977 gave the product's name as "Control Program for Microcomputers". The CP/M name follows

2378-631: The Digital Research distributed core of CP/M (BDOS, CCP, core transient commands) did not use any of the Z80-specific instructions, many Z80-based systems used Z80 code in the system-specific BIOS, and many applications were dedicated to Z80-based CP/M machines. Digital Research subsequently partnered with Zilog and American Microsystems to produce Personal CP/M, a ROM-based version of the operating system aimed at lower-cost systems that could potentially be equipped without disk drives. First featured in

2460-580: The IBM PC after DRI threatened legal action, it never overtook Microsoft's system. Most customers were repelled by the significantly greater price IBM charged for CP/M-86 over PC DOS ( US$ 240 and US$ 40, respectively). When Digital Equipment Corporation (DEC) put out the Rainbow 100 to compete with IBM, it came with CP/M-80 using a Z80 chip, CP/M-86 or MS-DOS using an 8088 microprocessor, or CP/M-86/80 using both. The Z80 and 8088 CPUs ran concurrently. A benefit of

2542-464: The IBM-compatible platform, and it never regained its former popularity. Byte magazine, at the time one of the leading industry magazines for microcomputers, essentially ceased covering CP/M products within a few years of the introduction of the IBM PC. For example, in 1983 there were still a few advertisements for S-100 boards and articles on CP/M software, but by 1987 these were no longer found in

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2624-562: The Intel 8080 processor into .A86 source code for the Intel 8086. The translator would also optimize the output for code size and take care of calling conventions, so that CP/M-80 and MP/M-80 programs could be ported to the CP/M-86 and MP/M-86 platforms automatically. XLT86 itself was written in PL/I-80 and was available for CP/M-80 platforms as well as for VAX/VMS . Many expected that CP/M would be

2706-480: The Intel-contracted PL/M compiler into a commercial enterprise. The Kildalls intended to establish the Digital Research brand and its product lines as synonymous with "microcomputer" in the consumer's mind, similar to what IBM and Microsoft together later successfully accomplished in making " personal computer " synonymous with their product offerings. Intergalactic Digital Research, Inc. was later renamed via

2788-513: The NIAT, a custom handheld computer designed for A. C. Nielsen 's internal use with 1  MB of SSD memory. In 1979, a multi-user compatible derivative of CP/M was released. MP/M allowed multiple users to connect to a single computer, using multiple terminals to provide each user with a screen and keyboard. Later versions ran on 16-bit processors. The last 8-bit version of CP/M was version 3, often called CP/M Plus, released in 1983. Its BDOS

2870-665: The OS and BIOS (this was also a common problem in early DOS machines). Bill Gates claimed that the Apple II with a Z-80 SoftCard was the single most-popular CP/M hardware platform. Many different brands of machines ran the operating system, some notable examples being the Altair 8800 , the IMSAI 8080 , the Osborne 1 and Kaypro luggables , and MSX computers. The best-selling CP/M-capable system of all time

2952-553: The Rainbow was that it could continue to run 8-bit CP/M software, preserving a user's possibly sizable investment as they moved into the 16-bit world of MS-DOS. A similar dual-processor adaption for the CompuPro System 816  [ sr ] was named CP/M 8-16 . The CP/M-86 adaptation for the 8085/8088-based Zenith Z-100 also supported running programs for both of its CPUs. Soon following CP/M-86, another 16-bit version of CP/M

3034-496: The S83 was quoted as $ 32 in 1,000 unit quantities. On most machines the bootstrap was a minimal bootloader in ROM combined with some means of minimal bank switching or a means of injecting code on the bus (since the 8080 needs to see boot code at Address 0 for start-up, while CP/M needs RAM there); for others, this bootstrap had to be entered into memory using front-panel controls each time

3116-537: The Sharp MZ-800, a cassette-based system with optional disk drives, Personal CP/M was described as having been "rewritten to take advantage of the enhanced Z-80 instruction set" as opposed to preserving portability with the 8080. American Microsystems announced a Z80-compatible microprocessor, the S83, featuring 8 KB of in-package ROM for the operating system and BIOS, together with comprehensive logic for interfacing with 64-kilobit dynamic RAM devices. Unit pricing of

3198-402: The ancestor of Borland Delphi , and Multiplan , the ancestor of Microsoft Excel , also debuted on CP/M before MS-DOS versions became available. VisiCalc , the first-ever spreadsheet program, was made available for CP/M. Another company, Sorcim , created its SuperCalc spreadsheet for CP/M, which would go on to become the market leader and de facto standard on CP/M. Supercalc would go on to be

3280-420: The basic concepts and mechanisms of early versions of MS-DOS resembled those of CP/M. Internals like file-handling data structures were identical, and both referred to disk drives with a letter ( A: , B: , etc.). MS-DOS's main innovation was its FAT file system. This similarity made it easier to port popular CP/M software like WordStar and dBase . However, CP/M's concept of separate user areas for files on

3362-498: The basis for the following systems: Several notable employees worked at Digital Research, some of which later made important contributions to the IT industry, such as: CP/M CP/M , originally standing for Control Program/Monitor and later Control Program for Microcomputers , is a mass-market operating system created in 1974 for Intel 8080 / 85 -based microcomputers by Gary Kildall of Digital Research, Inc. CP/M

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3444-531: The blocking and deblocking and the management of a disk buffer area is handled by model-specific code in the BIOS. Customization is required because hardware choices are not constrained by compatibility with any one popular standard. For example, some manufacturers designed built-in integrated video display systems, while others relied on separate computer terminals. Serial ports for printers and modems can use different types of UART chips, and port addresses are not fixed. Some machines use memory-mapped I/O instead of

3526-452: The command line. These are referred to as "transient" programs. On completion, BDOS will reload the CCP if it has been overwritten by application programs — this allows transient programs a larger memory space. The commands themselves can sometimes be obscure. For instance, the command to duplicate files is named PIP (Peripheral-Interchange-Program), the name of the old DEC utility used for that purpose. The format of parameters given to

3608-420: The development of GEM, Microsoft introduced Windows 1.0 . Digital Research (and later its successor Caldera ) accused Microsoft of announcing vaporware versions of MS-DOS to suppress sales of DR DOS. Concurrent PC DOS later evolved into the modular FlexOS (1986). This exploited the greater memory addressing capability of the new CPU to provide a more flexible multi-tasking environment. There

3690-450: The disk. From version 1.1 or 1.2 onwards, changing a disk then trying to write to it before its directory is read will cause a fatal error to be signalled. This avoids overwriting the disk but requires a reboot and loss of the data to be stored on disk. The majority of the complexity in CP/M is isolated in the BDOS, and to a lesser extent, the CCP and transient commands. This meant that by porting

3772-434: The first disk operating system for microcomputers . In 1974 he incorporated as Intergalactic Digital Research , with his wife handling the business side of the operation. The company soon began operating under its shortened name Digital Research. The company's operating systems, starting with CP/M for 8080 / Z80 -based microcomputers, were the de facto standard of their era. Digital Research's product suite included

3854-524: The following components: The only hardware system that CP/M, as sold by Digital Research, would support was the Intel 8080 Development System. Manufacturers of CP/M-compatible systems customized portions of the operating system for their own combination of installed memory, disk drives, and console devices. CP/M would also run on systems based on the Zilog Z80 processor since the Z80 was compatible with 8080 code. While

3936-409: The home market had been largely unsuccessful and most CP/M software was too expensive for home users. In 1986 the magazine stated that Kaypro had stopped production of 8-bit CP/M-based models to concentrate on sales of MS-DOS compatible systems, long after most other vendors had ceased production of new equipment and software for CP/M. CP/M rapidly lost market share as the microcomputing market moved to

4018-456: The keyboard and conveys results to the terminal. CP/M itself works with either a printing terminal or a video terminal. All CP/M commands have to be typed in on the command line . The console most often displays the A>; prompt, to indicate the current default disk drive. When used with a video terminal, this is usually followed by a blinking cursor supplied by the terminal. The CCP awaits input from

4100-546: The limited number of simple routines in the BIOS to a particular hardware platform, the entire OS would work. This significantly reduced the development time needed to support new machines, and was one of the main reasons for CP/M's widespread use. Today this sort of abstraction is common to most OSs (a hardware abstraction layer ), but at the time of CP/M's birth, OSs were typically intended to run on only one machine platform, and multilayer designs were considered unnecessary. The Console Command Processor, or CCP, accepts input from

4182-470: The lowest address of the BDOS was the Transient Program Area (TPA) available for CP/M application programs. Although all Z80 and 8080 processors could address 64 kilobytes of memory, the amount available for application programs could vary, depending on the design of the particular computer. Some computers used large parts of the address space for such things as BIOS ROMs, or video display memory. As

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4264-434: The lowest level functions required by the operating system. These include reading or writing single characters to the system console and reading or writing a sector of data from the disk. The BDOS handles some of the buffering of data from the diskette, but before CP/M 3.0 it assumes a disk sector size fixed at 128 bytes, as used on single-density 8-inch floppy disks. Since most 5.25-inch disk formats use larger sectors,

4346-500: The magazine. Later versions of CP/M-86 made significant strides in performance and usability and were made compatible with MS-DOS. To reflect this compatibility the name was changed, and CP/M-86 became DOS Plus , which in turn became DR-DOS . ZCPR (the Z80 Command Processor Replacement) was introduced on 2 February 1982 as a drop-in replacement for the standard Digital Research console command processor (CCP) and

4428-555: The manufacturer would still be required to pay a license fee to Microsoft for that system. This practice led to a US Department of Justice investigation, resulting in a decision in 1994 that barred Microsoft from "per-processor" licensing. Successive revisions of Concurrent CP/M incorporated MS-DOS API emulation (since 1983), which gradually added more support for DOS applications and the FAT file system . These versions were named Concurrent DOS (1984), with Concurrent PC DOS (1984) being

4510-523: The microcomputer industry. This computer platform was widely used in business through the late 1970s and into the mid-1980s. CP/M increased the market size for both hardware and software by greatly reducing the amount of programming required to port an application to a new manufacturer's computer. An important driver of software innovation was the advent of (comparatively) low-cost microcomputers running CP/M, as independent programmers and hackers bought them and shared their creations in user groups . CP/M

4592-451: The new IBM PC. When the IBM PC arrived in late 1981, it came with PC DOS , an OEM version of MS-DOS , which was developed from 86-DOS , which Microsoft had acquired for this purpose. By mid-1982, MS-DOS was also marketed for use in hardware-compatible non-IBM computers. This one decision resulted in Microsoft becoming the leading name in computer software. This story is detailed from

4674-586: The new filename. To remove certain characters of a file name in Microsoft Windows command prompt (XP & Higher) : This will remove abcd from the file name. Notes: Digital Research Digital Research, Inc. ( DR or DRI ) was a privately held American software company created by Gary Kildall to market and develop his CP/M operating system and related 8-bit, 16-bit and 32-bit systems like MP/M , Concurrent DOS , FlexOS , Multiuser DOS , DOS Plus , DR DOS and GEM . It

4756-434: The new location of the operating system in processor memory. This newly patched version can then be saved on a new disk, allowing application programs to access the additional memory made available by moving the system components. Once installed, the operating system (BIOS, BDOS and CCP) is stored in reserved areas at the beginning of any disk which can be used to boot the system. On start-up, the bootloader (usually contained in

4838-451: The operating system because "where there are literally thousands of programs written for it, it would be unwise not to take advantage of it", Xerox said. (Xerox included a Howard W. Sams CP/M manual as compensation for Digital Research's documentation, which InfoWorld described as atrocious, incomplete, incomprehensible, and poorly indexed. ) By 1984, Columbia University used the same source code to build Kermit binaries for more than

4920-424: The original 8-bit CP/M and its various offshoots like MP/M (1979), a multi-tasking multi-user version of CP/M. After Microsoft present MS-DOS that was based on CP/M , Digital Research released CP/M-86 , which was the first 16-bit system (1981, adapted to the IBM PC in early 1982), which was meant as direct competitor to MS-DOS . There followed the multi-tasking MP/M-86 (1981), and Concurrent CP/M (1982),

5002-666: The point of view of Microsoft and IBM in the PBS series Triumph of the Nerds , and from the point of view of Gary Kildall's friends and coworkers in The Computer Chronicles . The competition between MS-DOS and DR DOS is one of the more controversial chapters of microcomputer history. Microsoft offered better licensing terms to any computer manufacturer that committed to selling MS-DOS with every system they shipped, making it uneconomical for them to offer systems with another OS, since

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5084-513: The same disk was never ported to MS-DOS. Since MS-DOS had access to more memory (as few IBM PCs were sold with less than 64 KB of memory, while CP/M could run in 16 KB if necessary), more commands were built into the command-line shell , making MS-DOS somewhat faster and easier to use on floppy-based computers. Although one of the first peripherals for the IBM PC was a SoftCard-like expansion card that let it run 8-bit CP/M software, InfoWorld stated in 1984 that efforts to introduce CP/M to

5166-506: The same purpose. TSL PC-MOS includes an implementation of rename . Like the rest of the operating system, it is licensed under the GPL v3 . It is also available in the open source MS-DOS emulator DOSBox . Another example. This will rename a default video found in Windows 7 with a new name: The first parameter may contain a drive and a path, but the second parameter must contain only

5248-504: The standard operating system for 16-bit computers. In 1980 IBM approached Digital Research, at Bill Gates ' suggestion, to license a forthcoming version of CP/M for its new product, the IBM Personal Computer. Upon the failure to obtain a signed non-disclosure agreement , the talks failed, and IBM instead contracted with Microsoft to provide an operating system. The resulting product, MS-DOS , soon began outselling CP/M. Many of

5330-609: The system was started. CP/M used the 7-bit ASCII set. The other 128 characters made possible by the 8-bit byte were not standardized. For example, one Kaypro used them for Greek characters, and Osborne machines used the 8th bit set to indicate an underlined character. WordStar used the 8th bit as an end-of-word marker. International CP/M systems most commonly used the ISO 646 norm for localized character sets, replacing certain ASCII characters with localized characters rather than adding them beyond

5412-650: The time the IBM Personal Computer was being developed, Digital Research's CP/M was the dominant operating system of the day. In 1980, IBM asked Digital Research to supply a version of CP/M written for the Intel 8086 microprocessor as the standard operating system for the PC, which would use the code-compatible Intel 8088 chip. Digital Research, uneasy about the conditions related to making such an agreement with IBM, refused. Microsoft seized this opportunity to supply an OS, in addition to other software (e.g., BASIC ) for

5494-411: The user. A CCP internal command, of the form drive letter followed by a colon, can be used to select the default drive. For example, typing B: and pressing enter at the command prompt changes the default drive to B, and the command prompt then becomes B> to indicate this change. CP/M's command-line interface was patterned after the operating systems from Digital Equipment , such as RT-11 for

5576-485: The version adapted to run on IBM compatible PCs. In 1985, soon after the introduction of the 80286 -based IBM PC/AT , Digital Research introduced a real-time system, initially called Concurrent DOS 286 . Other single-user operative systems were launched: DOS Plus (1985) and DR DOS (1988). The latter system was marketed as a direct MS-DOS/PC DOS replacement with added functionality. In order to achieve this, it gave up built-in support to run CP/M applications and

5658-681: Was CP/M-68K for the Motorola 68000 . The original version of CP/M-68K in 1982 was written in Pascal/MT+68k , but it was ported to C later on. CP/M-68K, already running on the Motorola EXORmacs systems, was initially to be used in the Atari ST computer, but Atari decided to go with a newer disk operating system called GEMDOS . CP/M-68K was also used on the SORD M68 and M68MX computers. In 1982, there

5740-480: Was a small but powerful set of system APIs , each with a synchronous and an asynchronous variant. Pipes were supported, and all named resources could be aliased by setting environment variables . This system was to enjoy enduring favour in point-of-sale systems. Other successors of Concurrent DOS were Concurrent DOS XM (1986) and the 32-bit Concurrent DOS 386 (1987). In 1991 DR presented Multiuser DOS . Digital Research's multi-user family of operating systems

5822-454: Was able to increase the license to tens of thousands of dollars. Under Kildall's direction, the development of CP/M 2.0 was mostly carried out by John Pierce in 1978. Kathryn Strutynski , a friend of Kildall from Naval Postgraduate School (NPS), became the fourth employee of Digital Research Inc. in early 1979. She started by debugging CP/M 2.0, and later became influential as key developer for CP/M 2.2 and CP/M Plus. Other early developers of

5904-460: Was also a port from CP/M-68K to the 16-bit Zilog Z8000 for the Olivetti M20 , written in C , named CP/M-8000 . These 16-bit versions of CP/M required application programs to be re-compiled for the new CPUs. Some programs written in assembly language could be automatically translated for a new processor. One tool for this was Digital Research's XLT86 , which translated .ASM source code for

5986-527: Was changed to use DOS-compatible internal structures. It became a successful product line in itself. In 1985 Digital Research also produced a microcomputer version of the GKS graphics standard (related to NAPLPS ) called GSX , and later used this as the basis of their GEM GUI . Less known are their application programs, limited largely to the GSX-based DR DRAW and a small suite of GUI programs for GEM. After

6068-399: Was designed by David K. Brown. 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 Z80 processor. The system could be configured to support date stamping of files. The operating system distribution software also included

6150-463: Was developed and released. ZCPR 3.3 no longer supported the 8080 series of microprocessors, and added the most features of any upgrade in the ZCPR line. ZCPR 3.3 also included a full complement of utilities with considerably extended capabilities. While enthusiastically supported by the CP/M user base of the time, ZCPR alone was insufficient to slow the demise of CP/M. A minimal 8-bit CP/M system would contain

6232-508: Was eventually displaced by DOS following the 1981 introduction of the IBM PC . Gary Kildall originally developed CP/M during 1974, as an operating system to run on an Intel Intellec-8 development system, equipped with a Shugart Associates 8-inch floppy-disk drive interfaced via a custom floppy-disk controller . It was written in Kildall's own PL/M ( Programming Language for Microcomputers ). Various aspects of CP/M were influenced by

6314-426: Was initially written by a group of computer hobbyists who called themselves "The CCP Group". They were Frank Wancho, Keith Petersen (the archivist behind Simtel at the time), Ron Fowler, Charlie Strom, Bob Mathias, and Richard Conn. Richard was, in fact, the driving force in this group (all of whom maintained contact through email). ZCPR1 was released on a disk put out by SIG/M (Special Interest Group/Microcomputers),

6396-548: Was probably the Amstrad PCW . In the UK, CP/M was also available on Research Machines educational computers (with the CP/M source code published as an educational resource), and for the BBC Micro when equipped with a Z80 co-processor. Furthermore, it was available for the Amstrad CPC series, the Commodore 128 , TRS-80 , and later models of the ZX Spectrum . CP/M 3 was also used on

6478-489: Was sidelined with the previous single user operative systems. In one beta release of Windows 3.1 , Microsoft included hidden code (later called the AARD code ) that detected DR DOS and displayed a cryptic error message. Digital Research was purchased by Novell for US$ 80 million in 1991. primarily for Novell to gain access to the operating system line. FlexOS , this operative system had already been adopted as

6560-622: Was the first large software company in the microcomputer world. Digital Research was originally based in Pacific Grove, California , later in Monterey, California . In 1972, Gary Kildall , an instructor at the Naval Postgraduate School in Monterey, California , began working at Intel as a consultant under the business name Microcomputer Applications Associates (MAA). By 1974, he had developed Control Program/Monitor, or CP/M ,

6642-465: Was the project manager for the evolving CP/M-86 line of operating systems. At this point, the original 8-bit CP/M became known by the retronym CP/M-80 to avoid confusion. CP/M-86 was expected to be the standard operating system of the new IBM PCs , but DRI and IBM were unable to negotiate development and licensing terms. IBM turned to Microsoft instead, and Microsoft delivered PC DOS based on 86-DOS . Although CP/M-86 became an option for

6724-422: Was written for CP/M than for operating systems that ran on only one brand of hardware. One restriction on portability was that certain programs used the extended instruction set of the Z80 processor and would not operate on an 8080 or 8085 processor. Another was graphics routines, especially in games and graphics programs, which were generally machine-specific as they used direct hardware access for speed, bypassing

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