JOVIAL

JOVIAL is a high-level computer programming language similar to ALGOL, specialized for the development of embedded systems (specialized computer systems designed to perform one or a few dedicated functions, usually embedded as part of a complete device including mechanical parts).

History

JOVIAL was developed as a new "high-order" programming language beginning in 1959 by a team at System Development Corporation (SDC) headed by Jules Schwartz to compose software for the electronics of military aircraft.^[1] The name JOVIAL is an acronym for "Jules' Own Version of the International Algebraic Language" (The "International Algorithmic Language" (IAL) was a name originally proposed for ALGOL 58). According to Schwartz the language was originally called OVIAL, but this met with opposition for various reasons. "JOVIAL" was then suggested, with no meaning attached to the "J". Somewhat jokingly it was suggested that the language be named after Schwartz, since he was chairing the meeting, and this unofficial name stuck.^[2]

During the 1960s JOVIAL was a part of the US Military L-project series, in particular 465L (the SACCS project), due to a lack of real-time processing languages available. Some 95 percent of the SACCS project, managed by ITT with software primarily written by SDC, was written in JOVIAL. The software project took two years and fewer than 1400 programmer years, less than half of the equivalent time in the SAGE L-project.^[3]

During the late 1970s and early 1980s, the U.S. Air Force adopted a standardized CPU, the MIL-STD-1750A, and subsequent JOVIAL programs were built for that processor. Several commercial vendors provided compilers and related tools to build JOVIAL for processors such as the MIL-STD-1750A, including Advanced Computer Techniques (ACT), TLD Systems, Proprietary Software Systems (PSS), and others.^[4][5]

JOVIAL was standardized during 1973 with MIL-STD-1589 and was revised during 1984 with MIL-STD-1589C. It is still much used to update and maintain software on older military vehicles and aircraft. There are three dialects in common use: J3, J3B-2, and J73.

As of 2010, JOVIAL is no longer maintained and distributed by the USAF JOVIAL Program Office (JPO). Software previously distributed by the JPO is still available through commercial resources at Software Engineering Associates, Inc. (SEA) as are other combinations of host/target processors including Microsoft Windows, Linux, Mac OS X on PowerPC, SPARC, VAX, 1750A, PowerPC, TI-9989, Zilog Z800x, Motorola 680x0 and IBM System 360/System 370/System z. In addition DDC-I, which acquired parts of Advanced Computer Techniques, also still lists JOVIAL compilers and related tools.^[6]

Most software implemented in JOVIAL is mission critical, and maintenance is getting more difficult. In December 2014, it was reported that software derived from JOVIAL code produced in the 1960s was involved in a major failure of the United Kingdom's air traffic control infrastructure, and that the agency that uses it was having to train its IT staff in JOVIAL so they could maintain this software, which is not scheduled for replacement until 2016.^[7] Conversion of JOVIAL code to new platforms is therefore becoming more common. JOVIAL rehosting and retargeting is currently done by Software Engineering Associates. Conversions of JOVIAL to other languages is currently done by Semantic Designs, whose DMS Software Reengineering Toolkit was used to convert some of the JOVIAL mission software for the B-2 bomber to C.^[8]

Influence

According to Schwartz languages influenced by JOVIAL include CORAL, SYMPL, Space Programming Language (SPL), and to some extent CMS-2.^[9] An interactive subset of JOVIAL called TINT, similar to JOSS was developed in the 1960s.^[2]

Features

JOVIAL includes features not found in standard ALGOL, such as records, arrays of records, and inline assembly language.^[10]

Applications

Notable systems using JOVIAL include:

• Milstar Communications Satellite
• Advanced Cruise Missile
• B-52, B-1B,^[11] B-2 bombers *
• C-130, C-141, C-17 transport aircraft
• F-111, F-15, F-16 (prior to Block 50), F-117 fighter aircraft
• LANTIRN
• U-2 aircraft
• E-3 Sentry AWACS aircraft
• Navy Aegis cruisers
• Army Multiple Launch Rocket System (MLRS)
• Army UH-60 Black Hawk helicopters
• F100, F117, F119 jet engines
• NORAD air defense & control system (Hughes HME-5118ME system)
• NATO Air Defence Ground Environment (NADGE) system
• RL-10 rocket engines
• Civil NAS (National Airspace System) Air Traffic Control

Airborne radar systems with embedded JOVIAL software include the APG-70, APG-71 and APG-73.^[12]

Example

The following example is taken from COMPUTER PROGRAMMING MANUAL FOR THE JOVIAL (J73) LANGUAGE.^[13]

PROC RETRIEVE(CODE:VALUE);
   BEGIN
   ITEM CODE U;
   ITEM VALUE F;
   VALUE = -99999.;
   FOR I:0 BY 1 WHILE I<1000;
      IF CODE = TABCODE(I);
         BEGIN
         VALUE = TABVALUE(I);
         EXIT;
      END
   END

This example defines a procedure named RETRIEVE which takes an unsigned integer input argument CODE and a floating-point output argument VALUE. It searches the 1000-element array TABCODE for an entry that matches CODE, and then sets the floating-point variable VALUE to the element of array TABVALUE having the same matching array index. If no matching element is found, VALUE is set to −99999.0.

References

External links

• The Development of Jovial
• "MIL-STD-1589C, MILITARY STANDARD: JOVIAL (J73)" (PDF). United States Department of Defense. 6 Jul 1984.
• April 2006 archive of the JOVIAL Program Office
• Page on Jules Schwartz, including film of a humorous talk on the development of JOVIAL
• DODSSP U.S. Department of Defense Single Stock Point for Military Specifications, Standards and Related Publications
• Software Engineering Associates
• DDC-I, Inc.: DDC-I JOVIAL Compiler System (DJCS)
• Video of Jules Schwartz giving a humorous talk on the development of JOVIAL