FlexOS is a discontinued modular real-time multiuser multitasking operating system ( RTOS) designed for computer-integrated manufacturing, laboratory, retail and financial markets. Developed by Digital Research's Flexible Automation Business Unit in Monterey, California, in 1985, the system was considered to become a successor of Digital Research's earlier

Concurrent DOS Multiuser DOS is a Real-time operating system, real-time multi-user multi-tasking operating system for IBM Personal Computer, IBM PC-compatible microcomputers. An evolution of the older Concurrent CP/M-86, Concurrent DOS and Concurrent DOS 386 ...

, but with a new, modular, and considerably different system architecture and portability across several processor families. Still named Concurrent DOS 68K and Concurrent DOS 286, it was renamed into FlexOS on 1 October 1986 to better differentiate the target audiences. FlexOS was licensed by several OEMs who selected it as the basis for their own operating systems like

4680 OS FlexOS is a discontinued modular real-time multiuser multitasking operating system (RTOS) designed for computer-integrated manufacturing, laboratory, retail and financial markets. Developed by Digital Research's Flexible Automation Business U ...

4690 OS 4690 Operating System (sometimes shortened to 4690 OS or 4690) is a specially designed point of sale (POS) operating system, originally sold by IBM. In 2012, IBM sold its retail business, including this product, to Toshiba, which assumed support. ...

, S5-DOS/MT and others. Unrelated to FlexOS, the original Concurrent DOS system architecture found a continuation in successors like Concurrent DOS XM and

Concurrent DOS 386 Multiuser DOS is a real-time multi-user multi-tasking operating system for IBM PC-compatible microcomputers. An evolution of the older Concurrent CP/M-86, Concurrent DOS and Concurrent DOS 386 operating systems, it was originally developed by ...

as well.

Overview

Concurrent DOS 286, Concurrent DOS 68K and FlexOS were designed by Francis "Frank" R. Holsworth (using siglum FRH). Like Portable CP/M, Concurrent DOS 286, Concurrent DOS 68K and Concurrent DOS V60, FlexOS was written in C for higher portability across hardware platforms, and it featured very low interrupt latency and fast context switching. The original

protected mode In computing, protected mode, also called protected virtual address mode, is an operational mode of x86-compatible central processing units (CPUs). It allows system software to use features such as virtual memory, paging and safe multi-tasking d ...

FlexOS 286 version 1.3 was designed for host machines equipped with

286 __NOTOC__ Year 286 ( CCLXXXVI) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Maximus and Aquilinus (or, less frequently, year 1039 ...

CPUs, and with adaptations for NEC V60, NEC V70 and

Motorola 68000 The Motorola 68000 (sometimes shortened to Motorola 68k or m68k and usually pronounced "sixty-eight-thousand") is a 16/32-bit complex instruction set computer (CISC) microprocessor, introduced in 1979 by Motorola Semiconductor Products Sector ...

processors planned. FlexOS 286 executables using the system's native INT DCh ( INT 220) application program interface had the filename extension

.286 FlexOS is a discontinued modular real-time multiuser multitasking operating system (RTOS) designed for computer-integrated manufacturing, laboratory, retail and financial markets. Developed by Digital Research's Flexible Automation Business U ...

. A

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. Initial ...

API front-end In software engineering, the terms frontend and backend (or sometimes referred to as back end or back-end) refer to the separation of concerns between the presentation layer (''frontend''), and the data access layer (''backend'') of a piece of soft ...

(FE) was available as well, using the extension .CMD for executables. (A filename extension of

.68K FlexOS is a discontinued modular real-time multiuser multitasking operating system (RTOS) designed for computer-integrated manufacturing, laboratory, retail and financial markets. Developed by Digital Research's Flexible Automation Business U ...

was reserved for FlexOS 68K, a file extension derived from Concurrent DOS 68K as of 1986.) In May 1987, FlexOS version 1.31 was released for 80286 machines. The developer version required an IBM PC/AT-compatible machine with 640 KB of conventional and 512 KB of extended memory, and either a (monochrome) CGA or an EGA graphics adapter. FlexOS supported a concept of dynamically loadable and unloadable subdrivers, and it came with driver prototypes for floppies, hard disks, printers, serial interfaces, RAM disks, mice and console drivers. During boot, the FLEX286.SYS kernel would load the resource managers and device drivers specified in the CONFIG.SYS ''binary'' file (not to be mixed up with the similarly named

CONFIG.SYS CONFIG.SYS is the primary configuration file for the DOS and OS/2 operating systems. It is a special ASCII text file that contains user-accessible setup or configuration directives evaluated by the operating system's DOS BIOS (typically residing ...

configuration file under DOS), and its shell (COMMAND.286) would execute a CONFIG.BAT startup batch job instead of the common

AUTOEXEC.BAT AUTOEXEC.BAT is a system file that was originally on DOS-type operating systems. It is a plain-text batch file in the root directory of the boot device. The name of the file is an abbreviation of "automatic execution", which describes its funct ...

. FlexOS's optional DOS emulator provided limited PC DOS 2.1 compatibility for DOS .COM and .EXE programs. Certain restrictions applied in "

8086 emulation mode Virtual DOS machines (VDM) refer to a technology that allows running 16-bit/32-bit DOS and 16-bit Windows programs when there is already another operating system running and controlling the hardware. Overview Virtual DOS machines can operate ei ...

" since these programs were executed in the processor's protected mode. Due to bugs in earlier steppings of the Intel 80286, the FlexOS 286 DOS front-end required at least the 80286 E2 stepping to function properly (see LOADALL). These problems had already caused delays in the delivery of Concurrent DOS 286 earlier. The system optionally supported a multitasking GEM

VDI VDI may refer to: * Verein Deutscher Ingenieure, the Association of German Engineers * Vidalia Regional Airport (IATA code: VDI) *Vietnam Defence Industry, Vietnam's General Department of Defense Industry. Technology * Virtual Desktop Infras ...

for graphical applications. FlexOS 1.31 could be linked with none, either or both of these two modules. FlexOS 1.31 also supported FlexNet. By June 1987 there were also versions 1.0 of FlexOS 386 (for hosts) and FlexOS 186 (for remote cell controllers). FlexOS 386 provided a windowing feature, and offered PC DOS 3.2 and GEM compatibility. FlexOS 286 and FlexOS 386 versions 2.0 were registered on 3 July 1989. Among the major FlexOS customers in 1990/1991 were FANUC, IBM,

ICL ICL may refer to: Companies and organizations * Idaho Conservation League * Imperial College London, a UK university * Indian Confederation of Labour * Indian Cricket League * Inorganic Chemistry Laboratory of the University of Oxford * Israel Ch ...

, Nixdorf,

Siemens Siemens AG ( ) is a German multinational conglomerate corporation and the largest industrial manufacturing company in Europe headquartered in Munich with branch offices abroad. The principal divisions of the corporation are ''Industry'', '' ...

TEC TEC may refer to: Education * Technology, the subject itself of technology taught at schools * Tertiary Education Commission (disambiguation) *''The East Carolinian'', a campus newspaper of East Carolina University Governmental and public organiz ...

, Thorn EMI Software and Micrologic.

Novell Novell, Inc. was an American software and services company headquartered in Provo, Utah, that existed from 1980 until 2014. Its most significant product was the multi-platform network operating system known as Novell NetWare. Under the lead ...

bought Digital Research for million in July 1991. '' X/GEM for FlexOS release 1.0'' (a.k.a. X/GEM FlexOS 286 and 386) and FlexNet were registered on 21 December 1992. FlexOS was used as the primary test platform for the new Novell Embedded Systems Technology (NEST). When Novell decided to abandon further development of the various Digital Research operating systems such as Multiuser DOS (a successor to Concurrent DOS) and Novell DOS (a successor to DR DOS), they sold FlexOS off to the Santa Clara, California-based Integrated Systems Inc. (ISI) for million in July 1994. The deal comprised a direct payment of half this sum as well as shares representing 2% of the company. The company already had pSOS+, another modular real-time multitasking operating system for embedded systems, but they continued to maintain FlexOS as well. FlexOS version 2.33 was current as of May 1998 and with FlexOS 2.34 to be released soon after with added support for faster CPUs, 64 MB of memory, EIDE and ATAPI CDROM drives. Integrated Systems was bought by their competitor Wind River Systems in February 2000.

Commands

The following list of

commands Command may refer to: Computing * Command (computing), a statement in a computer language * COMMAND.COM, the default operating system shell and command-line interpreter for DOS * Command key, a modifier key on Apple Macintosh computer keyboards * ...

is supported by FlexOS: * ASSIGN * BACK *

BACKUP In information technology, a backup, or data backup is a copy of computer data taken and stored elsewhere so that it may be used to restore the original after a data loss event. The verb form, referring to the process of doing so, is "back up", w ...

* BREAK * CANCEL *

CHDIR The command, also known as (change directory), is a command-line shell command used to change the current working directory in various operating systems. It can be used in shell scripts and batch files. Implementations The command has been ...

* CHKDSK * COMMAND * COMP * CONFIG * COPY * CTTY * DATE * DEFINE * DIR * DISKCOMP * DISKCOPY * DISKSET * ERASE * EXIT * FDISK * FIND *

FORMAT Format may refer to: Printing and visual media * Text formatting, the typesetting of text elements * Paper formats, or paper size standards * Newspaper format, the size of the paper page Computing * File format, particular way that informatio ...

* FSET * LIST * LOGOFF * LOGON *

MKDIR The mkdir (make directory) command in the Unix, DOS, DR FlexOS, IBM OS/2, Microsoft Windows, and ReactOS operating systems is used to make a new directory. It is also available in the EFI shell and in the PHP scripting language. In DOS, OS/2, ...

* MORE * ORDER * PASSWORD * PATH *

PRINT Printing is the process for reproducing text and images using a master form or template Print or printing may also refer to: Publishing * Canvas print, the result of an image printed onto canvas which is often stretched, or gallery-wrapped, o ...

* PROCESS *

PROMPT Prompt may refer to: Computing * Command prompt, characters indicating the computer is ready to accept input * Command Prompt, also known as cmd.exe or cmd, the command-line interpreter in some operating systems * Prompt (natural language), instr ...

* RECDIR * RECFILE *

RENAME Rename may refer to: * Rename (computing), rename of a file on a computer * RENAME (command), command to rename a file in various operating systems * Rename (relational algebra) In relational algebra, a rename is a unary operation written as \r ...

RESTORE Restore may refer to: * ReStore - Retail building supply stores run by local Habitat for Humanity affiliates *"Restore", a single by Chris August Christopher August Megert (born March 20, 1982) is an American Contemporary Christian musician who ...

* RMDIR * SECURITY *

SORT Sort may refer to: * Sorting, any process of arranging items in sequence or in sets ** Sorting algorithm, any algorithm for arranging elements in lists ** Sort (Unix), a Unix utility which sorts the lines of a file ** Sort (C++), a function in the ...

* SYS * TIME * TREE *

TYPE Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

* VER *

VOL Vol or Vols may refer to: * Vol (command), a computer operating system command * Vol (heraldry), a heraldic charge * Volatility (finance) * Volume (disambiguation) * Volunteer (Irish republican) * Nashville Vols, an American minor league baseball t ...

Versions

Known FlexOS versions include:

/ Freescale/

NXP NXP Semiconductors N.V. (NXP) is a Dutch semiconductor designer and manufacturer with headquarters in Eindhoven, Netherlands. The company employs approximately 31,000 people in more than 30 countries. NXP reported revenue of $11.06 billion in 2 ...

ColdFire MCF5251 The NXP ColdFire is a microprocessor that derives from the Motorola 68000 family architecture, manufactured for embedded systems development by NXP Semiconductors. It was formerly manufactured by Freescale Semiconductor (formerly the semiconductor ...

platform: * Concurrent DOS 68K 1.0 (1985) * Concurrent DOS 68K 1.1 * Concurrent DOS 68K 1.20 (April 1986, 1986-05-27) * Concurrent DOS 68K 1.21 (1986) * FlexOS 68K 1.x? Intel 80286 platform: * MP/M-286 (1982) * Concurrent CP/M-286 (1985) * Concurrent DOS 286 preview (1985-01) * Concurrent DOS 286 1.0 (1985-08-06) ** Concurrent DOS 286 1.0.01 (1985-08-18/1985-08-21) ** Concurrent DOS 286 1.0.02 (1985-08-22/1985-09-12) ** Concurrent DOS 286 1.0.03 (1985-09-10/1985-09-12) ** Concurrent DOS 286 1.0.04 (1985-09-17) ** Concurrent DOS 286 1.0.05 (1985-11-01) ** Concurrent DOS 286 1.0.06 (1985-12-10) * Concurrent DOS 286 1.1 (1986-01-07) * Concurrent DOS 286 1.2 (1986) ** Concurrent DOS 286 1.2.00 (1986-04-10/1986-04-24) ** Concurrent DOS 286 1.2.01 (1986-04-16/1986-05-19) ** Concurrent DOS 286 1.2.02 (1986-08-18) * FlexOS 286 1.3 (November 1986) * FlexOS 286 1.31 (May 1987) * FlexOS 286 1.5 (1988-02-29) * FlexOS 286 2.0.00 (1988-03-31) * FlexOS 286 2.0 (July 1989) * FlexOS 286 2.32 (July 1993)

Intel 80186 The Intel 80186, also known as the iAPX 186, or just 186, is a microprocessor and microcontroller introduced in 1982. It was based on the Intel 8086 and, like it, had a 16-bit external data bus multiplexed with a 20-bit address bus. The 801 ...

/ NEC V20/ V30 platform: * FlexOS 186 (1986-09-04 forked) * FlexOS 186 1.0 (June 1987) Intel 80386 platform: * FlexOS 386 1.0 (June 1987) * FlexOS 386 2.0 (July 1989) * FlexOS 386 2.30? * FlexOS 386 2.31? * FlexOS 386 2.32 (July 1993) * FlexOS 386 2.33 (May 1998) * FlexOS 386 2.34 (planned for 1999) NEC V60 platform: * Concurrent DOS V60?

Adaptations

IBM 4680 OS

Named IBM 4680 OS Version 1, IBM originally chose DR Concurrent DOS 286 as the basis of their ''IBM 4680'' computer for IBM Plant System products and Point-of-Sale terminals in 1986. The last release of the IBM 4680 OS has been Version 4, before it was replaced by IBM 4690 Version 1. Versions: * IBM 4680 Operating System Version 1 Release 1 * IBM 4680 Operating System Version 1 Release 2 * IBM 4680 Operating System Version 1 Release 3 * IBM 4680 Operating System Version 2 Release 1 * IBM 4680 Operating System Version 3 Release 1 * IBM 4680 Operating System Version 4 Release 1

IBM and Toshiba 4690 OS

In July 1993, IBM announced the adoption of FlexOS version 2.32 as the basis of their IBM 4690 OS Version 1, to be pre-released on 24 September 1993 and generally made available from 25 March 1994. FlexOS 2.32 supported 286 and 386 modes, had more efficient memory management, better console and pipe systems, and brought overall quality and performance improvements compared to the version that came with IBM 4680 OS Version 4. Further, it removed limits on the number of applications running concurrently due to its more efficient use of KOSPOOL. To support Java, IBM 4690 OS Version 2 added support for

long filename Long filename (LFN) support is Microsoft's backward-compatible extension of the 8.3 filename (short filename) naming scheme used in DOS. Long filenames can be more descriptive, including longer filename extensions such as .jpeg, .tiff, .html, a ...

s by means of a virtual filesystem (VFS) architecture and it introduced FAT32 volumes. According to "The Year of the Store?", IHL Consulting Group/RIS News, IBM 4690 OS still had a market share of 12% in the

POS POS, Pos or PoS may refer to: Linguistics * Part of speech, the role that a word or phrase plays in a sentence * Poverty of the stimulus, a linguistic term used in language acquisition and development * Sayula Popoluca (ISO 639-3), an indigenous l ...

register/client market in June 2005, when IBM was starting to phase it out in favour to IBM Retail Environment for SUSE (IRES). IBM continued to maintain 4690 OS up to April 2015, with the most recent version released by IBM in May 2012 being IBM 4690 OS Version 6 Release 3. Toshiba released Toshiba 4690 OS Version 6 Release 4 in January 2014 and Version 6 Release 5 in January 2016.

Siemens S5-DOS/MT

used and still maintains FlexOS in their factory automation equipment as well. For example, their Simatic S5 STEP-5 operating system S5-DOS/MT is based on FlexOS 386 with X/GEM, FlexNet and Btrieve, whereas the smaller S5-DOS system, also present on these systems, is a variant of Digital Research's

Personal CP/M-86 CP/M-86 was a version of the CP/M operating system that Digital Research (DR) made for the Intel 8086 and Intel 8088. The system commands are the same as in CP/M-80. Executable files used the relocatable .CMD file format. Digital Research als ...

. Siemens industrial systems like COROS LS-B/FlexOS, COROS OS-B/FlexOS, GRACIS/FlexOS, OS-525 were FlexOS and X/GEM-based. Computers such as the PC 16-20 and the PC 32 series were available with FlexOS as well.

CTM

The Japanese post office shared terminals III and CTM IV were based on FlexOS.