Legacy Software – Tools, Support, & Migration


There are hundreds of millions of lines of legacy code in use in today’s key military, commercial avionics, and other systems. Most of these legacy systems were developed from the 1970s through the 1990s with obsolescent (or obsolescing) programming languages – or required the support of antiquated development systems which are no longer serviceable – or were reliant upon discontinued electronics. As a result, legacy systems are increasingly difficult and expensive to maintain and upgrade.


DDC-I Legacy Software Solutions

To solve legacy software issues, DDC-I offers several tools and services based on our core competencies and over twenty years of corporate expertise. First, DDC-I offers support of legacy software languages and tools which enable older applications to be extended and maintained within their original software development framework. Second, as a compiler vendor with safety critical expertise, DDC-I is uniquely able to provide industry leading software experts for legacy software assessment studies and engineering services. DDC-I has numerous migration program successes, acting as a subcontractor or directly with the end customer – with a penchant for delivering quality results, on-time.

Legacy Software Tool Support

Legacy Software Tool Support

DDC-I offers long-term support for legacy software products, including those for JOVIAL and Ada 83. These legacy products complement our newer SCORE product line, and share a common pedigree which makes transitions to SCORE easier.


Compiler Products Legacy JOVIAL DDC-I TADS DACS
Language J73 Ada 83 (with Ada 95 extensions) Ada 83
Target(s) 17050A, 8000, 8002 i960, 1750A
and 68xxx
x86 and MIPS
Hosts VAX/VMS, Solaris VAX/VMS, Solaris, MS-Windows VAX/VMS, Solaris,


DDC-I Migration Services & Tools

Languages JOVIAL J73 Ada 83
Compiler Products Legacy JOVIAL TADS DACS
Targets 1750A, 8000, 8002 i960, 1750A, and 68xxx x86 and MIPS
Hosts VAX/VMS, Solaris VAX/VMS, Solaris,MS-Windows VAX/VMS, Solaris, MS-Windows
Optional Tools DARTS - DO-178 Run-Time
Verification & Analysis Tools
Multi-Processor Environment Tools
Atlas Support Program

Customers can rely on DDC-I for legacy software tool products and support. These legacy products complement our newer SCORE® product lines, and share a common pedigree which makes migration to DDC-I's newer products simpler & easier.

DDC-I Migration Assessment Studies

DDC-I Migration Assessment Studies

In-depth technical studies of the options, risks, and a suggested technical strategy to migrate legacy applications to new target hardware, development environments, compiler versions, or onto newer programming languages. DDC-I's Migration Assessment studies offer a cost-effective, qualified, and third party view of the efforts and expenses involved in a language, target, or host migration.


  • Outlines current environment
  • Identifies application-specific migration issues
  • Assesses the risks of the migration
  • Recommends solutions based on risk mitigation and costs
  • Provides work breakdowns
  • Provides refined cost & labor estimates
  • Includes applicable quotes if DDC-I were to perform the migration


  • Interim step before committing to a migration project
  • Scopes the migration effort
    • Cost
    • Labor (in-house or out-source)
    • Schedule
  • Removes technical "unknowns"
  • Presents technical management strategies

Migrating software can be a sensitive or costly venture. This is especially the case for legacy applications as they are more difficult to port due to a host of potential pitfalls (e.g., programming language nuisances, compiler [vendor] implementations, runtime and hardware dependencies, use of extensions beyond the defined programming language, application code structures, etc.). Further, migrating applications may impact prior (e.g., DO-178) certification efforts. DDC-I's Migration Assessment Studies resolves these unknowns, by providing a comprehensive technical study that identifies the migration's technical challenges, proposes technical solutions and recommendations of how to approach the migration effort, and a manpower and, if applicable, DDC-I's service cost estimates. DDC-I Migration Assessment Studies are independent of other DDC-I services, and may be used to simply help scope and manage internal resources for migration efforts.


Migration Assessment Study Processes start with an initial set of technical conference call(s) followed by an on-site study of the application and the development environment. This on-site study is performed by a DDC-I software expert, who is selected based upon the type of migration considered. As applicable, an on-site study often includes recompiling part of the application to the new language host, or target environment, and may include an in-depth analysis of the user's development environment and applicable third party software tools and code bases. From this vantage point, the DDC-I expert then returns to DDC-I and develops the Migration Assessment Study which undergoes a series of internal DDC-I peer reviews before it is presented to the customer.

Language Conversion Tools & Services

Language Conversion Tools & Services


* DDC-I doesn't recommend migrating safety critical applications to C/C++ without considerable study.

Migrating an application from one programming application to another is oftentimes considered when a host or target change is required, or when it's difficult or unfeasible to continue maintaining a legacy application in its current language. Due to cost & scheduling implications, migrating software becomes much more appealing versus a total rewrite. For example, mission or safety critical software may cost well over $10/line (and towards $100/line for safety critical with artifacts), and take years to create. Whereas, migrating legacy software may cost a few dollars per line, or less, and can often be redeployed within a year.

DDC-I offers both engineering services and tools to convert an application's language. DDC-I is uniquely qualified for language conversion due to our in-depth knowledge of embedded programming and programming language semantics and intricacies, gained by being a leading compiler and service supplier. This background enables DDC-I to provide unique tools, which operate like no other, and provide services that result in quality and on-time deliveries.

Language Conversion Services

DDC-I has software services expertise to assist converting applications from one programming language to another. Converting applications is not always trivial-even when using conversion tools. The reasons are twofold: First, an application may have used compiler vendor features that are outside of the language definitions. Second, if the application is mission or safety critical, the converted application must be carefully scrutinized and compared to the original application to make sure it operates correctly from a functional and performance perspective. This may require the development of a new test harness to characterize the functional and performance attributes of the initial system which can then be used to qualify the migrated software against (along with any applicable current certification tests). In almost all cases, before undertaking a language conversion, DDC-I recommends that one start out with a Migration Assessment Study to first scope the technical considerations and amount of work a compiler migration will take.


JOVIAL convert is a unique and DDC-I proprietary conversion tool that's demonstratable, and available today. This tool addresses the general concern of JOVIAL being an essentially dead language, making it difficult to maintain, port, and upgrade. DDC-I's solution is to provide a semi-automated service that makes it relatively easy and inexpensive to convert legacy JOVIAL code into C code, which then can be maintained and upgraded by C programmers.


  • JOVIAL to C converter
  • Retains original application software structure
  • Transposes source code
  • Recommends solutions based on risk mitigation and costs
  • 1750/MIPS-based (Contact DDC-I for availability of other targets)
  • Includes services contacts


  • Fast and highly efficient converter
  • Produces compilable code
  • Readable
  • Maintainable (Migrated Code)
  • Supportable
  • Easier to certify over other conversion methods

Please contact DDC-I Sales regarding Ada to C, Ada to Java, and other Language Conversion tools.

Target & Host Migration Services

Target & Host Migration Services

DDC-I Services arm offers software migration specialists that reduce risks and cut development schedules for most any migration project, including those that involve safety critical and secure processing. Customers can leverage DDC-I's unique engineering competencies as part of their own team, or outsource software work directly to DDC-I on a fix fee, or time & materials basis. DDC-I also engages in these services with various program teams for contract vehicles such as AMCOM Express, F2AST, R23G, DESP II, etc.

Target Migration

Target Migratio Services assists customers with re-hosting a development environment, with or without safety certification. Target Migration services are also ingrained to DDC-I as part of our compiler target support. Oftentimes target migrations are done in combination with a language and/or host migration strategy. DDC-I can assist in removing from any target hardware dependencies and in porting the application to a new target environment. DDC-I can also assist in optimizing the result and in system integration qualification.

Host Migration


Host Migration Services assists customers with re-hosting a development environment, with or without safety certification. Host Migration services are second nature for DDC-I, as these services are oftentimes a direct result of our compiler expertise and product offerings and the consolidation of the Ada market. No matter if you are currently using TADS, DACS, or another Ada offering, DDC-I can provide a host migration to address host system obsolescence or other factors that may drive host migration. DDC-I has DO-178 and other safety critical backgrounds and these services can include safety critical recertification assistance.

Compiler Vendor or Compiler Version Migration Services

Compiler Vendor or Compiler Version Migration Services

ConversionPCIncludes upgrading the application to more current language versions, or to replace a defunct, ill-supported, or aged compiler technologies with DDC-I's modern tool chain.

Legacy applications must often change compiler version or vendors throughout a program's lifetime. This change is oftentimes coincides with a host or target migration, or may simply be driven by the need to move to a current language version, reduce or eliminate licensing costs, or to replace a defunct, ill-supported, or aged compiler technology. In all cases, DDC-I has software services expertise to assist in these transitions. For example, DDC-I has several customers who have migrated from old versions of Tartan Ada running Cxx processors, which is no longer supported or required expensive runtime licenses, to DDC-I's SCORE environment using C4x DSPs or Power Architecture technology targets.

MigrationAssessmentMigrating from one Ada environment to another is not always trivial - especially if the application wasn't written to be portable by staying clear of compiler vendor-specific features (refer to Not All Adas Were Created Equal sidebar). In almost all cases, it is highly recommended that one starts out with a Migration Assessment Study to first scope the technical considerations and amount of work a compiler migration will take.