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CP/M

A screenshot of CP/M-86.
Website Digital Research offical CP/M page
Company/
developer		 Digital Research, Inc. / Gary Kildall
Source model Open source
Latest stable release 3. A website (alternatively web site or Web site, a back-construction from the Proper noun World Wide Web) is a collection of Web pages The software industry comprises businesses involved in the development, maintenance and publication of Computer software. A software developer is a person or organization concerned with facets of the software development process wider than design and coding a somewhat broader scope of Digital Research Inc (aka DR or DRI; originally Intergalactic Digital Research) was the company created by Dr Gary Arlen Kildall (May 19 1942 – July 11 1994 was an American Computer scientist and Microcomputer Entrepreneur who created the CP/M Open source is a development methodology which offers practical accessibility to a product's source (goods and knowledge 1 / 1982
Available programming languages(s) Assembler, BASIC, Modula-2, Pascal etc. Year 1982 ( MCMLXXXII) was a Common year starting on Friday (link displays the 1982 Gregorian calendar) A programming language is an Artificial language that can be used to write programs which control the behavior of a machine particularly a Computer. See the terminology section below for information regarding inconsistent use of the terms assembly and assembler In Computer programming, BASIC (an Acronym for Beginner's All-purpose Symbolic Instruction Code) is a family of High-level programming languages Modula-2 is a computer Programming language invented by Niklaus Wirth at ETH, around 1978 as a successor to his intermediate language Modula
Supported platforms Intel 8080, Intel 8085, Intel 8086, Motorola 68000, Zilog Z80
Kernel type Monolithic kernel
Default user interface Command line interface
License Originally Proprietary, now BSD-like
Working state Historic

CP/M (Control Program for Microcomputers) is an operating system originally created for Intel 8080/85 based microcomputers by Gary Kildall of Digital Research, Inc. The Intel 8080 was an early Microprocessor designed and manufactured by Intel. The Intel 8085 is an 8-bit Microprocessor introduced by Intel in 1977 The 8086 is a 16-bit Microprocessor chip designed by Intel and introduced on the market in 1978 which gave rise to the X86 architecture The Motorola 68000 is a 16/32-bit CISC Microprocessor core designed and marketed by Freescale Semiconductor (formerly Motorola Semiconductor The Zilog Z80 is an 8-bit Microprocessor designed and sold by Zilog from July 1976 onwards In Computer science, the kernel is the central component of most computer Operating systems (OS A monolithic kernel is a kernel architecture where the entire kernel is run in Kernel space in Supervisor mode. The user interface (or Human Computer Interface) is the aggregate of means by which people&mdash the users '&mdash interact with the System A software license (or software licence in commonwealth usage is a Legal instrument governing the usage or redistribution of copyright protected software Proprietary software is Computer software on which the producer has set restrictions on use private modification copying, or republishing. BSD licenses represent a family of Permissive free software licences. An operating system (commonly abbreviated OS and O/S) is the software component of a Computer system that is responsible for the management and coordination The Intel 8080 was an early Microprocessor designed and manufactured by Intel. The Intel 8085 is an 8-bit Microprocessor introduced by Intel in 1977 microcomputer is a Computer with a Microprocessor as its Central processing unit. Gary Arlen Kildall (May 19 1942 – July 11 1994 was an American Computer scientist and Microcomputer Entrepreneur who created the CP/M Digital Research Inc (aka DR or DRI; originally Intergalactic Digital Research) was the company created by Dr Initially confined to single tasking on 8-bit processors and no more than 64 kilobytes (64 KiB) of memory, later versions of CP/M added multi-user variations, and were migrated to 16-bit processors. Eight-bit CPUs normally use an 8-bit data bus and a 16-bit address bus which means that their Address space is limited to 64 KBs This is not a "natural A kilobyte (derived from the SI prefix Kilo -, meaning 1000 is a unit of Information or Computer storage equal to either 1024 A kibibyte (a contraction of ki lo bi nary byte) is a unit of Information or Computer storage, established by the International

The combination of CP/M and S-100 bus computers patterned on the MITS Altair was an early "industry standard" for microcomputers, and was widely used through the late 1970s and into the mid-'80s. The S-100 bus, IEEE696 -1983 (withdrawn, was an early Computer bus designed in 1974 as a part of the Altair 8800, generally considered today The MITS Altair 8800 was a Microcomputer design from 1975 based on the Intel 8080 CPU and sold as a mail-order kit through advertisements in By greatly reducing the amount of programming required to install an application on a new manufacturer's computer, CP/M increased the market size for both hardware and software.

Contents

Hardware model

A minimal 8-bit CP/M system would contain 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 able to execute 8080 code. The Zilog Z80 is an 8-bit Microprocessor designed and sold by Zilog from July 1976 onwards While CP/M itself did not use any of the Z80-specific instructions, many applications were dedicated to Z80 based CP/M machines.

Components of the operating system

In the 8-bit versions, CP/M's software was separated into three components

The CCP and BDOS were the same in all installations of a particular revision of CP/M, but the BIOS portion was always adapted to the particular hardware. Adding memory to a computer, for example, meant that the CP/M system had to be reinstalled. Once installed, the operating system was stored in reserved areas at the beginning of each floppy disk. On power-up, the ROM-resident bootloader would look for a floppy disk in drive A: and load from it the operating system.

By modern standards CP/M was primitive owing to the extreme constraints on program size. With version 1. 0 there was no provision for detecting a changed disk. If a user changed disks without manually rereading the disk directory the system would write on the new disk using the old disk's data, ruining the data stored on the disk. Starting with 1. 1 or 1. 2 this danger was reduced: if one changed disks without reading the new disk's directory, and tried to write to it, the operating system would signal a fatal error, avoiding overwriting but requiring a reboot (which took no more than a few seconds, but destroyed the data you were trying to save).

The majority of the complexity in CP/M was isolated in the BDOS, and to a lesser extent, the CCP. This meant that by porting the limited number of simple commands 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, 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.

Command processor

The command processor or CCP accepted input from the keyboard. All CP/M commands had to be typed in on the "command line" — the screen would show most often A> and would await input from the user.

CP/M's command line interface was patterned after the operating systems from Digital Equipment, such as RSTS/E for the PDP-11. Digital Equipment Corporation was a pioneering American company in the Computer industry RSTS (pronounced as "RIST-ess" or "RIST-uhs" is a Multi-user Time-sharing Operating system, developed by Digital Equipment Corporation The PDP-11 was a series of 16-bit Minicomputers sold by Digital Equipment Corp

Commands generally took the form of a keyword followed by a list of parameters separated by spaces or special characters. If an internal command was recognized, it was carried out by the CCP itself. Otherwise it would attempt to find an executable file on the currently logged disk drive and user area, load it, and pass it any additional parameters from the command line. On completion of a transient program, CP/M would reload the part of the CCP that had been overwritten by application programs — this allowed transient programs a larger memory space.

The commands themselves could sometimes be obscure. For instance, the command to duplicate files was named PIP (Peripheral-Interchange-Program), the name of the old DEC utility used for that purpose. Peripheral Interchange Program (PIP was a utility to transfer data files on Digital Equipment Corporation 's computers Digital Equipment Corporation was a pioneering American company in the Computer industry The format of parameters given to a program was not yet standardized, so that there was no single "option character" that differentiated options from file names (only the last version of CP/M included options in square brackets fairly consistently).

Basic disk operating system

The basic disk operating system (BDOS) provided access to such operations as opening a file, output to the console, or printing. Application programs would 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 was the same independent of the amount of memory in the system, application programs would run the same way for any type or configuration of hardware.

Basic input output system

The basic input output system or BIOS provided the lowest level functions required by the operating system. These included reading or writing single characters to the system consoles and reading or writing a sector of data from the disk. The BDOS handled some of the buffering of data from the diskette, but before CP/M 3. 0 it assumed a fixed disk sector size of 128 Bytes, as used on single-density 8-inch floppy disks. Since most 5. 25-inch disk formats used larger sectors, the blocking and deblocking and the management of a disk buffer area was handled by model-specific code in the BIOS.

File system

File names consisted of up to 8 characters, a period, then up to three characters as a file name extension (8.3 filename convention). An 83 filename (also called a short filename or SFN) is a Filename convention used by old versions of DOS and versions of Microsoft Windows The extension usually identified the type of the file. For example, . COM indicated a binary executable program file, and . TXT indicated a file containing ASCII text. American Standard Code for Information Interchange ( ASCII)

File size was specified as the number of 128-byte records (directly corresponding to disk sectors on 8-inch drives) occupied by a file on the disk. There was no generally supported way of specifying byte-exact file sizes. The current size of a file was maintained in the file's file control block (FCB) by the operating system. A File Control Block ( FCB) is a file system structure in which the state of an open file is maintained Since many application programs (such as text editors) prefer to deal with files as sequences of characters rather than as sequences of records, by convention text files were terminated with a control-Z character (ASCII SUB, hexadecimal 1A). A text editor is a type of program used for editing plain Text files Text editors are often provided with Operating systems or software development In Computing, control-Z is a Control character in ASCII code, also known as the substitute ( SUB) character American Standard Code for Information Interchange ( ASCII) Substitute character (␚ A control character that is used in the place of a character that is recognized to be invalid or in error or that cannot be represented on a given device Determining the end of a text file therefore involved examing the last record of the file to locate the terminating control-Z. In Computing, end-of-file, commonly abbreviated EOF, is a condition in a computer Operating system where no more data can be read from a data source A text file (sometimes spelled "textfile" is a kind of Computer file that is structured as a sequence of lines. This also meant that inserting a control-Z character into the middle of a file usually had the effect of truncating the text contents of the file.

File modification times (timestamps) were not supported, although some later variants of CP/M added this feature as an extension. In Computer science and Computer programming, system time represents a computer system's notion of the passing of Time.

CP/M 2. 2 had no sub-directories in the file structure but provided 16 "user areas" to organize files on a disk. The user area concept was to make the single-user version of CP/M somewhat compatible with multi-user MP/M systems. A common patch for the CP/M and derivative operating systems was to make one user area accessible to the user independent of the currently set user area. A supported command was "USER x" where x is a value from 0 to 15. User 0 was the default. If one changed to another user, such as USER 1, the material saved on the disk for this user would only be available to USER 1; USER 2 would not be able to see it or access it. Since CP/M was a single-user operating system, no security was provided for the user command; nothing would prevent any user from accessing any of the 16 user areas. The user area feature arguably had little utility on small floppy disks, though it was more useful for organizing files on machines equipped with large hard drives. A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device

History

The beginning and CP/M's heyday

In 1974 CP/M was a private project of Gary Kildall, under the name "Control Program/Monitor". 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 name shows a prevailing naming scheme of the time, as in Kildall's/Intel's PL/M (Programming Language for Microcomputers) 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 used when working at the Naval Postgraduate School, and which, like TOPS-10, has clear similarities to the CP/M user interface and file system. The PL/M programming language (an acronym of P rogramming L anguage for M icrocomputers)is a high-level language developed by Gary The PL/P programming language (an acronym of P rogramming L anguage for P rime (computers) is a medium-level language developed by PL/I ("Programming Language One" ˌpiːˌɛlˈwʌn is an imperative computer Programming language designed for scientific engineering CP/CMS was a Time-sharing Operating system of the late 60s and early 70s known for its excellent performance and advanced features The Naval Postgraduate School (NPS is a research university at the graduate-school level operated by the United States Navy. The TOPS-10 System was a computer Operating system from Digital Equipment Corporation (DEC for the PDP-10 released in 1964, the resulting systems [1]

This renaming of CP/M was part of a larger effort by Kildall and his business-partner wife to convert Kildall's personal project of CP/M and the Intel-contracted PL/M compiler into a commercial enterprise. The Kildalls astutely 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 IBM and Microsoft product offerings. Intergalactic Digital Research, Inc. was later renamed via a corporation change-of-name filing to Digital Research, Inc.

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. 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 the 7-bit boundary. ISO 646 is an ISO standard that since 1972 has specified a 7- Bit character code from which several national standards are derived

While graphics-capable S100 systems existed from the commercialization of the S100 bus, CP/M did not provide any standardized graphics support until the release of CP/M 3. The S-100 bus, IEEE696 -1983 (withdrawn, was an early Computer bus designed in 1974 as a part of the Altair 8800, generally considered today 0 with GSX (Graphic System eXtension). Owing to the small memory available, graphics was never a common feature associated with 8-bit CP/M operating systems.

While the 8-inch single density format (so-called "distribution format") was standardized, various 5¼ inch formats were used depending on the characteristics of particular systems and to some degree the choices of the designers. No single manufacturer prevailed in the 5¼ inch era of CP/M use. A software manufacturer had to prepare a separate version of the program for each brand of hardware on which it was to run. With some manufacturers (Kaypro is an example), there was not even standardization across the company's different models. Because of this situation, disk format translation programs, which allowed a machine to read many different formats, became popular and reduced the confusion, as did programs like kermit which allowed transfer of data and programs from one machine to another using the serial ports that most CP/M machines had. Kermit is a Computer file transfer/management protocol and a set of communications software tools primarily used in the early years of personal computing in the 1980s In Telecommunications, RS-232 (Recommended Standard 232 is a standard for serial binary data signals connecting between a DTE ( Data Terminal Equipment The fragmented CP/M market, requiring distributors either to stock multiple formats of disks or to invest in multiformat duplication equipment, compared with the more standardized IBM PC disk formats, was a contributing factor to the rapid obsolescence of CP/M after 1981.

CP/M 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 between different machines, usually only requiring specification of the escape sequence for control of the screen and printer. This article refers to codes used as commands for computing devices A computer terminal is an electronic or electromechanical hardware device that is used for entering data into and displaying data from a Computer or a Computing This portability made CP/M popular, and much more software was written for CP/M than for operating systems that only ran on 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.

Many different brands of machines ran CP/M, some notable examples being the Altair, the IMSAI 8080, the Osborne 1 and Kaypro portables, MSX, and even the Apple II when an extra Z80-card was installed. History In May 1972 William Millard began business individually as IMS Associates (IMS in the area of computer consultancy and engineering using his home The Osborne 1 was the first commercially successful portable Microcomputer, released in April 1981 by Osborne Computer Corporation. Kaypro Corporation, commonly called Kaypro, was an American home / Personal computer manufacturer of the 1980s MSX was the name of a standardized Home computer architecture in the 1980s The best selling CP/M capable system of all time was probably the Commodore 128, although few people actually used its CP/M abilities. The Commodore 128 ( C128, CBM 128, C=128) home / Personal computer was the last 8-bit machine which was commercially In the UK, CP/M was also available for the BBC Micro when equipped with a Z80 co-processor. Furthermore, it powered the popular Amstrad PCW word-processing system and was available for the Amstrad CPC series and later models of the ZX Spectrum. The Amstrad PCW series ( '''P'''ersonal '''C'''omputer '''W'''ord processor) was British company Amstrad 's versatile line of home/personal The Amstrad CPC is a series of 8-bit Home computers produced by Amstrad Plc during the 1980s and early 1990s The Sinclair ZX Spectrum is an 8-bit personal Home computer released in the United Kingdom in 1982 by Sinclair Research Ltd

WordStar, one of the first widely used word processors, and dBASE, an early and popular database program for small computers, were originally written for CP/M. WordStar was a Word processor application published by MicroPro, originally written for the CP/M operating system but later ported to DOS, that dBase was the first widely used Database management system (DBMS for Microcomputers published by Ashton-Tate for CP/M, and later on the An early outliner, KAMAS (Knowledge and Mind Amplification System) was also written for CP/M, though later rewritten for MS-DOS. An outliner is a special Text editor that allows text to be structured as an Outline. Turbo Pascal, the ancestor of Borland Delphi, and Multiplan, the ancestor of Microsoft Excel, also debuted on CP/M before MS-DOS versions became available. Turbo Pascal is a complete software development system that includes a Compiler and an Integrated Development Environment (IDE for the Pascal programming language Multiplan was an early Spreadsheet program developed by Microsoft. In Computing, Microsoft Excel (full name Microsoft Office Excel) consists of a proprietary Spreadsheet -application written and distributed Various character or text-based games were written. Lifeboat Associates started collecting and distributing user-written "free" software. One of the first was XMODEM, which allowed communication via modem and phone line. XMODEM is a simple File transfer protocol developed as a quick hack by Ward Christensen for use in his 1977 MODEM Modem (from mo dulator- dem odulator is a device that modulates an analog carrier signal to encode Digital information

The 16-bit world

Versions of CP/M were later completed for some 16-bit CPUs as well, although they required the application programs to be re-compiled for the new CPUs -- or, if they were written in assembly language, to be largely rewritten from scratch. See the terminology section below for information regarding inconsistent use of the terms assembly and assembler

One of the first was CP/M-86 for the Intel 8086, which was soon followed by CP/M-68k for the Motorola 68000. CP/M-86 was a version of the CP/M operating system that Digital Research made for the Intel 8086 and Intel 8088. The 8086 is a 16-bit Microprocessor chip designed by Intel and introduced on the market in 1978 which gave rise to the X86 architecture The Motorola 68000 is a 16/32-bit CISC Microprocessor core designed and marketed by Freescale Semiconductor (formerly Motorola Semiconductor At this point the original 8-bit CP/M became known by the retronym CP/M-80 to avoid confusion. Eight-bit CPUs normally use an 8-bit data bus and a 16-bit address bus which means that their Address space is limited to 64 KBs This is not a "natural A retronym is a type of Neologism coined for an old object or concept whose original name has come to be used for something else is no longer unique or is otherwise inappropriate There was also a port to the Zilog Z8000, named CP/M-8000[1]. The Z8000 was a 16-bit Microprocessor introduced by ZiLOG in 1979

CP/M-68k was initially used in the Atari ST computer, but Atari decided to go with a newer DOS called GEMDOS. The Atari ST is a home / Personal computer that was commercially available from 1985 to the early 1990s GEM ( G raphical E nvironment M anager was a Windowing system created by Digital Research Inc It also was used on the SORD M68 and M68MX computers. 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. International Business Machines Corporation abbreviated IBM and nicknamed "Big Blue", is a multinational Computer Technology IBM turned to Microsoft instead, and Microsoft delivered PC-DOS based on a CP/M "clone," 86-DOS. Microsoft Corporation is an American multinational Computer technology Corporation, which rose to dominate the Home computer IBM PC-DOS is a DOS operating system for the IBM Personal Computer, sold throughout the 1980s and 1990s 86-DOS was an operating system developed and marketed by Seattle Computer Products for its Intel 8086 -based computer kit Although CP/M-86 became an option for the IBM PC after DRI threatened legal action, it never overtook Microsoft's system.

When Digital Equipment Corporation put out the Rainbow 100 to compete with IBM, it came with CP/M-80 using a Z80 chip, and CP/M-86 or MS-DOS using an 8088 microprocessor. Digital Equipment Corporation was a pioneering American company in the Computer industry The Rainbow 100 was a Microcomputer introduced by Digital Equipment Corporation (DEC in 1982 to compete in the IBM PC market The Z80 and 8088 CPUs ran concurrently. A benefit of the Rainbow was that it could continue to run 8-bit CP/M software as users moved into the 16-bit world of MS-DOS.

MS-DOS takes over

The first version of MS-DOS had some resemblance to CP/M-86, but rapidly diverged after the first release. MS-DOS (short for M icro' s' oft D isk O perating S ystem is an Operating system commercialized by Microsoft. Many of the basic concepts and internal mechanisms of early versions of MS-DOS resembled those of CP/M. MS-DOS (short for M icro' s' oft D isk O perating S ystem is an Operating system commercialized by Microsoft. Internals like file-handling data structures were identical, and both referred to disk drives with a letter (A:, B:, etc. ). The main innovation was MS-DOS's FAT file system. Templateinfobox filesystem whilst covering all 3 file systems please make any style changes to both at the same time In Computing, a file system (often also written as filesystem) is a method for storing and organizing Computer files and the data they contain to make This intentional similarity made it easier to port popular CP/M software like WordStar and dBase. WordStar was a Word processor application published by MicroPro, originally written for the CP/M operating system but later ported to DOS, that dBase was the first widely used Database management system (DBMS for Microcomputers published by Ashton-Tate for CP/M, and later on the However, CP/M's concept of separate user areas for files on 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 had to run in 16 KB if necessary), more commands were built in to the command-line user interface logic, making MS-DOS somewhat faster and easier to use on floppy-based computers. The user interface (or Human Computer Interface) is the aggregate of means by which people&mdash the users '&mdash interact with the System

CP/M rapidly lost market share as the microcomputing market moved to the PC 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. Byte magazine was an influential Microcomputer magazine in the late 1970s and throughout the 1980s because of its wide-ranging editorial coverage For example, in 1983 there were still a few advertisements for S100 boards and articles on CP/M software, but by 1987 these were no longer found in the magazine. Year 1983 ( MCMLXXXIII) was a Common year starting on Saturday (link displays the 1983 Gregorian calendar) Year 1987 ( MCMLXXXVII) was a Common year starting on Thursday (link displays 1987 Gregorian calendar)

Later versions of CP/M-86 made significant strides in performance and usability and were made compatible with MS-DOS. For some time in the 1980s, the resulting system was considered to be a better x86 OS than MS-DOS. To reflect this compatibility the name was changed, and CP/M-86 became DOS Plus, which in turn became DR-DOS. DOS Plus (also known as DOS+ is an operating system written by Digital Research, first released in 1985 DR-DOS is a DOS -type Operating system for IBM PC - compatible Personal computers, originally developed by Gary Kildall

ZCPR

ZCPR (the Z80 Command Processor Replacement) was introduced on February 2, 1982 as a drop-in replacement for the standard Digital Research command processor (CCP) and 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. Simtel is an Internet -based archive of Shareware for various operating systems particularly Microsoft Windows and MS-DOS. Robert Bruce Mathias ( November 17 1930 - September 2 2006) was an American decathlete, two-time Olympic gold 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), a part of the Amateur Computer Club of New Jersey. New Jersey ( is a state in the Mid-Atlantic and Northeastern regions of the United States.

ZCPR2 was released on February 14, 1983. Events 842 - Charles the Bald and Louis the German swear the Oaths of Strasbourg in the French and German Year 1983 ( MCMLXXXIII) was a Common year starting on Saturday (link displays the 1983 Gregorian calendar) 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. The Intel 8080 was an early Microprocessor designed and manufactured by Intel. The Intel 8085 is an 8-bit Microprocessor introduced by Intel in 1977

ZCPR3 was released on Bastille Day, July 14, 1984, as a set of nine disks from SIG/M. Bastille Day is the French national holiday, celebrated on 14 July each year. Events 1223 - Louis VIII becomes King of France upon the death of his father Philip II of France. Year 1984 ( MCMLXXXIV) was a Leap year starting on Sunday (link displays the 1984 Gregorian calendar) The code for ZCPR3 could also be compiled (with reduced features) for the 8080 and would run on systems that did not have the requisite Z80 microprocessor. The Zilog Z80 is an 8-bit Microprocessor designed and sold by Zilog from July 1976 onwards

In January of 1987, Richard Conn decided to stop developing ZCPR, and Echelon asked Jay Sage (who already had a privately enhanced ZCPR 3. 1) to continue work on ZCPR. Thus, ZCPR 3. 3 was developed and released. ZCPR33 no longer supported the 8080 series of microprocessors, and added the most features of any upgrade in the ZCPR line.

Features of ZCPR as of version 3 included:

ZCPR3. 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.

Further reading

See also

References

  1. ^ See www.khet.net for one opinion about a connection between CP/M and CP/CMS. As a CP/CMS user, Kildall would no doubt have seen this as a logical system name.

External links

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