Tel: +44(0)1865 300 579
Fax: +44(0)1865 300 232


Please note that LF64 is still under active development.
Other compilers are fully supported but development is not taking place at this present time.
Essential Lahey Fortran 90
Essential LF90 is a Fortran language system for students, engineers, and scientists who want to write programs using the modern features of Fortran 90. It is a 32-bit language system providing the essential features of the Fortran 90 standard.
In supporting older FORTRAN 77 code, the Fortran 90 Standard includes often redundant and sometimes inefficient language features from the past. In Essential Lahey Fortran 90 Lahey Computer Systems Inc. have streamlined the 90 Standard into one highly efficient and powerful Fortran 90 subset.
New in Essential LF90 v4.0:-
Winteracter Starter Kit, WiSK
The Winteracter Starter Kit, WiSK, is a 32-bit Windows and Fortran 90 graphics development toolkit for creating Windows user-interfaces and displaying graphics. WiSK is a subset of the full Winteracter Library. WiSK includes MenuED and DialogED -- interactive, visual design tools for creating Windows menus and dialog boxes.
Fortran 95 features
Lahey ED Developer
Long filename support is implemented for all functions, including debugging. We enabled the editing and saving of files with extensions .RC (resource files), .C, and .H. New Lahey Fortran toolbar buttons are added for WiSK MenuED and DialogED. New user-definable color schemes, scrollable window bar tabs, status bar improvements, default colors, and separate toolbars for LF95, LF90, and Essential LF90 are included.
Long filename support
Long filenames are supported in the compiler, linker and other utilities (except as arguments to the CFIG386 and REBINDB).
Native, 32-bit Windows tools
The compiler, driver, librarian, linker, and a few other utilities are now native, 32-bit Windows applications. This resolves some previously reported problems running these tools under NT.
Development platforms
Essential LF90 now operates only on the Windows 9x and NT operating systems. DOS, Windows 3.1x, and Win32s are supported for target application platforms.
New target application type
When used in combination, the -BIND and -WINCONSOLE compiler options will build the target application as a bound, extended DOS and 32-bit Windows console application. This will run as a native Windows application if executed under Windows 9x or NT, and will run as a DOS Extended application under straight DOS or Windows 3.1x.
New compiler option -WIN
Specify -WIN to build native, 32-bit Windows applications. The -WINCONSOLE option is still available for programs utilizing console I/O.
New compiler option -PAUSE
Running a program built with the -WINCONSOLE and -PAUSE options causes the following message to display when the program completes execution: "Program completed. Press Enter to Continue." Use the -NPAUSE option to suppress this feature. This feature was added to keep the console window open for viewing output.
Installation program enhancements
Install takes advantage of Windows 9x and NT Autoplay and offers online registration.
Language changes
The STOP statement no longer accepts a stop code. Construct Names are no longer permitted on block IF and CASE construct statements. CASE DEFAULT must be last case in a CASE construct. Variables declared but never used and variables set but never used now receive warnings instead of fatal errors.
LISK is removed
LISK, the Lahey INTERACTER Starter Kit, is removed in favor of WiSK, described above.
Essential Lahey Fortran 90 enforces structured Fortran 90 coding, removes obsolescent and redundant Fortran 77 and 90 features, and preserves the strengths of the Fortran language.
Why should you teach with Essential LF90?-
Essential LF90 is a clean, self-contained language with few redundancies, appropriate for teaching the basics of modern Fortran programming. Here's what Essential LF90 does:
Essential LF90 does retain statement labels for the sake of input-output exception handling and DO WHILE in recognition of its popularity in some quarters. With Essential LF90, programs are more easily maintained and can still be run on the full Lahey Fortran 90 or any other compiler that supports the 90 standard.
Fortran-Smart Windows Development Environment-
Essential LF90 includes a Windows Development Environment featuring the Fortran-smart Windows Editor and the Fortran-smart Debugger.

Fortran-Smart Windows Editor-
Lahey ED for Windows leads the way in intelligent, language-sensitive editing. Up and running straight out of the box for the new user but still highly configurable, ED fits the way you want to work:
Find Errors: Lahey ED automatically highlights syntax and semantic errors generated by the compiler and positions the cursor on the offending line in your source code.
Reduce Errors: Color syntax highlighting makes errors obvious and dramatically reduces compile-edit cycles.
Save Time: Drag & drop text using the mouse. Right click to look up functions in other source files and do bracket matching.
Boost Productivity: Lahey ED formats and writes code for you with smart indenting, code templates, auto-correction, code completion, and automatic case conversion. You'll produce legible, correct code quicker than ever before.
Fortran-Smart Windows Debugger-
Incrementally execute your program: Single step through your program. Step into or over calls to other routines.
Stop on Break Points: Click in the margin of your source code to set break points.
Display Variables: Right click on a variable to display its value.
Watch Variables: Open a watch window to show variable values in any active program unit.
Complementing the Windows Development Environment, Essential LF90 includes a 32-bit extended-DOS debugger and execution profiler, the Phar Lap TNT DOS-Extender, a linker, librarian, virtual memory manager, and over 550 pages of online documentation describing the language features and tools. Essential LF90 runs on Windows 3.1x, Windows 95, and Windows NT. You can create 32-bit Windows console-mode programs and 32-bit extended-DOS programs. Using the Winteracter Starter Kit, you can create 32-bit Windows applications with menus and dialog boxes.
Winteracter Starter Kit-
Essential LF90 v4.0 includes the Winteracter Starter Kit - WiSK - for creating true Windows programs with Fortran. WiSK is a subset of the Winteracter Library created by Interactive Software Services, Ltd. (Winteracter is available from Lahey.) Winteracter is a Fortran 90-callable, 32-bit, Windows, user-interface and graphics development kit. Derived from Winteracter, WiSK provides a library of subroutines for window management, input handling, dialog management, and high resolution graphics, plus custom versions of the visual menu and dialog designers. The enhanced WiSK offers semi-modeless dialog boxes, radio buttons, improvements to the visual dialog and menu editors, and a handful of miscellaneous new procedures.
The visual menu designer, MenuEd, allows you to create menus in the conventional Windows horizontal format or as Windows 95 and NT floating menus. MenuEd saves menu layouts as reusable resource scripts. Essential LF90 automatically compiles these scripts with the resource compiler and links the menus into your WiSK program. MenuEd also saves a Fortran source file containing type declaration statements with PARAMETER attributes defining identifiers for each item in the menu resource file. This file can be USE'd by a WiSK program allowing you to reference items in the menu using meaningful names.

The visual dialog designer, DialogED, allows you to interactively create Windows dialogs. Like MenuEd, DialogEd generates resource scripts and module files defining the identifiers of each dialog control. Various standard field types and controls are supported including string fields, list boxes, combo boxes, group boxes, push-buttons, picture frames, and labels. DialogED also offers a "test" button to try out your dialogs without having to build or rebuild your application.

Structured coding practice required by Essential LF90-
Obsolescent and redundant features removed from Essential LF90- To promote a more efficient and modern programming language the Fortran 90 features listed below are not supported in the Essential LF90 language. If you use a Fortran 90 feature that is not supported, an on-screen error message is provided.
Essential LF90 Statements- ALLOCATEAssignment Statement BACKSPACE CALL CASE CASE DEFAULT CHARACTER CLOSE COMPLEX CONTAINS CYCLE DEALLOCATE Derived-TYPE Definition Statement DO DO WHILE ELSE ELSE IF ELSEWHERE END DO END FILE END FUNCTION END IF END INTERFACE END MODULE END PROGRAM END SELECT END SUBROUTINE END TYPE END WHERE EXIT FORMAT FUNCTION GO TO IF IF...THEN IMPLICIT NONE INQUIRE INTEGER INTERFACE LOGICAL MODULE MODULE PROCEDURE NAMELIST NULLIFY OPEN OPTIONAL Pointer Assignment Statement PRIVATE PROGRAM PUBLIC READ REAL RETURN REWIND SELECT CASE SEQUENCE STOP SUBROUTINE TYPE USE WHERE WRITE Essential LF90 System Requirements- Windows® 9x or NT®80486DX, Pentium, Pentium Pro, Pentium II or compatible processor 24 MB RAM 25 MB available hard disk space |
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