Editing FLEX (operating system) (section)

==Overview==
The original version was distributed on [[list of floppy disk formats|8-inch floppy disks]]; the (smaller) version for 5.25-inch floppies is called mini-Flex. It was also later ported to the [[Motorola 6809]]; that version is called Flex09.<ref>[http://www.flexusergroup.com/flexusergroup/fug10.htm FAQs], FLEX User Group</ref> All versions are 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 are supported by TSC software, some hardware supports elementary graphics and pointing devices.

FLEX is a disk-based operating system, using 256-byte sectors on soft-sectored floppies; the disk structure uses linkage bytes in each sector to indicate the next sector in a file or free list. The directory structure is  simplified as a result. TSC (and others) provide several programming languages including [[BASIC]] in two flavors (standard and extended) and a tokenizing version of extended BASIC called Pre-compiled BASIC, [[Forth (programming language)|FORTH]], [[C (programming language)|C]], [[Fortran|FORTRAN]], and [[Pascal (programming language)|PASCAL]].

TSC also wrote a version of FLEX, ''Smoke Signal DOS'', for the California hardware manufacturer [[Smoke Signal Broadcasting]]; this version uses forward and reverse linkage bytes in each sector which increase disk reliability at the expense of compatibility and speed.

Later, TSC introduced the [[computer multitasking|multitasking]], [[multi-user]], [[Unix-like]] [[UniFLEX]] operating system, which requires [[Direct memory access|DMA]] disk controllers, 8" disk, and sold in 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 32/64|Dragon 64]] [[home computer]].

===Commands===
The following [[command (computing)|commands]] are supported by different versions of the FLEX operating system.<ref>[http://www.flexusergroup.com/flexusergroup/pdfs/miniflex.pdf FLEX User’s Manual (miniFLEX)]</ref><ref>[http://www.flexusergroup.com/flexusergroup/pdfs/flex2um.pdf FLEX 2.0 User's Manual]</ref><ref>[http://www.flexusergroup.com/flexusergroup/pdfs/swflexum.pdf FLEX 9.0 User’s Manual]</ref>

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* APPEND
* ASN
* [[Backup|BACKUP]]
* BUILD
* CAT
* [[copy (command)|COPY]]
* COPYNEW
* C4MAT
* CLEAN
* [[date (command)|DATE]]
* DELETE
* [[echo (command)|ECHO]]
* EXEC
* FIX
* GET
* I
* JUMP
* LINK
* LIST
* MEMTEST1
* MON
* N
* NEWDISK
* O
* P
* P.COR
* PO
* [[print (command)|PRINT]]
* PROT
* PSP
* Q
* QCHECK
* READPROM
* [[ren (command)|RENAME]]
* RM
* S
* SAVE
* SAVE.LOW
* SBOX
* SP
* STARTUP
* [[touch (command)|TOUCH]]
* TTYSET
* UCAL
* USEMF
* [[ver (command)|VER]]
* VERIFY
* VERSION
* WRITPROM
* XOUT
* Y
{{Div col end}}