FLEX (operating system)
Encyclopedia
The FLEX single-tasking operating system
was developed by Technical Systems Consultants
(TSC) of West Lafayette, Indiana
, for the Motorola 6800
in 1976. The original version was for 8" floppy disks and the (smaller) version for 5.25" floppies was called mini-Flex. It was also later ported to the Motorola 6809
; that version was called Flex9. All versions were text-based and intended for use on display devices ranging from printing terminals like the Teletype
Model 33 ASR to smart terminals. While no graphic displays were supported by TSC software, some hardware manufacturers supported elementary graphics and pointing devices.
It was a disk-based operating system, using 256-byte sectors on soft-sectored floppies; the disk structure used linkage bytes in each sector to indicate the next sector in a file or free list. The directory structure was much simplified as a result. TSC (and others) provided several programming languages including BASIC
in two flavors (standard and extended) and a tokenizing version of extended BASIC called Pre-compiled BASIC, FORTH, C
, FORTRAN
, and PASCAL
.
TSC also wrote a version of FLEX, Smoke Signal DOS, for the California hardware manufacturer Smoke Signal Broadcasting; this version used forward and back linkage bytes in each sector which increased disk reliability at the expense of compatibility and speed.
Later, TSC introduced the multitasking
, multi-user
, Unix-like
UniFLEX
operating system, which required DMA disk controllers, 8" disk, and so sold in only small numbers. Several of the TSC computer languages were ported to UniFLEX.
During the early 1980s, FLEX was offered by Compusense Ltd as an operating system for the 6809-based Dragon 64
home computer
.
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
was developed by Technical Systems Consultants
Technical Systems Consultants
Technical Systems Consultants was a US software company.Headquartered first in West Lafayette, Indiana and later moved to Chapel Hill, North Carolina, it was the foremost supplier of software for SWTPC compatible hardware, as well as many other early makes of personal computers...
(TSC) of West Lafayette, Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
, for the Motorola 6800
Motorola 6800
The 6800 was an 8-bit microprocessor designed and first manufactured by Motorola in 1974. The MC6800 microprocessor was part of the M6800 Microcomputer System that also included serial and parallel interface ICs, RAM, ROM and other support chips...
in 1976. The original version was for 8" floppy disks and the (smaller) version for 5.25" floppies was called mini-Flex. It was also later ported to the Motorola 6809
Motorola 6809
The Motorola 6809 is an 8-bit microprocessor CPU from Motorola, designed by Terry Ritter and Joel Boney and introduced 1978...
; that version was called Flex9. All versions were text-based and intended for use on display devices ranging from printing terminals like the Teletype
Teletype Corporation
The Teletype Corporation, a part of American Telephone and Telegraph Company's Western Electric manufacturing arm since 1930, came into being in 1928 when the Morkrum-Kleinschmidt Company changed its name to the name of its trademark equipment...
Model 33 ASR to smart terminals. While no graphic displays were supported by TSC software, some hardware manufacturers supported elementary graphics and pointing devices.
It was a disk-based operating system, using 256-byte sectors on soft-sectored floppies; the disk structure used linkage bytes in each sector to indicate the next sector in a file or free list. The directory structure was much simplified as a result. TSC (and others) provided several programming languages including BASIC
BASIC
BASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use - the name is an acronym from Beginner's All-purpose Symbolic Instruction Code....
in two flavors (standard and extended) and a tokenizing version of extended BASIC called Pre-compiled BASIC, FORTH, C
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
, FORTRAN
Fortran
Fortran is a general-purpose, procedural, imperative programming language that is especially suited to numeric computation and scientific computing...
, and PASCAL
Pascal (programming language)
Pascal is an influential imperative and procedural programming language, designed in 1968/9 and published in 1970 by Niklaus Wirth as a small and efficient language intended to encourage good programming practices using structured programming and data structuring.A derivative known as Object Pascal...
.
TSC also wrote a version of FLEX, Smoke Signal DOS, for the California hardware manufacturer Smoke Signal Broadcasting; this version used forward and back linkage bytes in each sector which increased disk reliability at the expense of compatibility and speed.
Later, TSC introduced the multitasking
Computer multitasking
In computing, multitasking is a method where multiple tasks, also known as processes, share common processing resources such as a CPU. In the case of a computer with a single CPU, only one task is said to be running at any point in time, meaning that the CPU is actively executing instructions for...
, multi-user
Multi-user
Multi-user is a term that defines an operating system or application software that allows concurrent access by multiple users of a computer. Time-sharing systems are multi-user systems. Most batch processing systems for mainframe computers may also be considered "multi-user", to avoid leaving the...
, Unix-like
Unix-like
A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....
UniFLEX
UniFlex
UniFLEX is a Unix-like operating system developed by Technical Systems Consultants for the Motorola 6809 family which allowed multitasking and multiprocessing. It was released for DMA-capable 8" floppy, extended memory addressing hardware , Motorola 6809 based computers. Examples included machines...
operating system, which required DMA disk controllers, 8" disk, and so sold in only small numbers. Several of the TSC computer languages were ported to UniFLEX.
During the early 1980s, FLEX was offered by Compusense Ltd as an operating system for the 6809-based Dragon 64
Dragon 32/64
The Dragon 32 and Dragon 64 are home computers that were built in the 1980s. The Dragons are very similar to the TRS-80 Color Computer , and were produced for the European market by Dragon Data, Ltd., in Port Talbot, Wales, and for the US market by Tano of New Orleans, Louisiana...
home computer
Home computer
Home computers were a class of microcomputers entering the market in 1977, and becoming increasingly common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single nontechnical user...
.