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59-575: The MicroEngine runs a special release III p-System. The enhancements of release III were incorporated into release IV which was made publicly available for other platforms but not for the MicroEngine. The MicroEngine series of products was offered at various levels of integration: The MicroEngine chipset was based on the MCP-1600 chipset, which formed the basis of the DEC LSI-11 low-end minicomputer and

118-460: A Zilog Z80 and a bipolar memory mapper harnessed to a microengine chipset on the second board, linked by a direct cable. The sole configuration known to be still running in 2018 and documented on the web is described by Marcus Wigan and contains 312 kB of memory, RAM disc support through a modified Z80 BIOS (written by Tom Evans) taking advantage of the memory mapping chip on the Z80 board, and using

177-781: A distributed Ada database, and object-oriented design. Ada is also used in other air traffic systems, e.g., the UK's next-generation Interim Future Area Control Tools Support (iFACTS) air traffic control system is designed and implemented using SPARK Ada. It is also used in the French TVM in- cab signalling system on the TGV high-speed rail system, and the metro suburban trains in Paris, London, Hong Kong and New York City. Preliminary Ada can be found in ACM Sigplan Notices Vol 14, No 6, June 1979 Ada

236-464: A function of several parameters. These parameters are those which are normally considered during the decode of a macroinstruction. The PTA was designed specifically to eliminate most of the overhead of macroinstruction translation. Essentially a macroinstruction opcode is quickly translated into an address that is loaded onto the Location Counter, creating a jump to the appropriate microcode to handle

295-496: A limited form of region-based memory management ; also, creative use of storage pools can provide for a limited form of automatic garbage collection, since destroying a storage pool also destroys all the objects in the pool. A double- dash ("--"), resembling an em dash , denotes comment text. Comments stop at end of line; there is intentionally no way to make a comment span multiple lines, to prevent unclosed comments from accidentally voiding whole sections of source code. Disabling

354-508: A programming language generally suitable for the department's and the UK Ministry of Defence 's requirements. After many iterations beginning with an original straw-man proposal the eventual programming language was named Ada. The total number of high-level programming languages in use for such projects fell from over 450 in 1983 to 37 by 1996. HOLWG crafted the Steelman language requirements ,

413-406: A reference to an instance of a specified type; untyped pointers are not permitted. Special types provided by the language are task types and protected types. For example, a date might be represented as: Important to note: Day_type, Month_type, Year_type, Hours are incompatible types, meaning that for instance the following expression is illegal: The predefined plus-operator can only add values of

472-454: A semaphore. This performance advantage was eroded by the later availability of p-code to native machine code translators, and mainstream 16-bit microprocessors such as the Intel 8086 and Motorola 68000 . When details of the MicroEngine were first released, the system accumulated a very large number of pre-orders (for the time). The first boards shipped were poorly designed (power and ground traces

531-644: A series of documents stating the requirements they felt a programming language should satisfy. Many existing languages were formally reviewed, but the team concluded in 1977 that no existing language met the specifications. Requests for proposals for a new programming language were issued and four contractors were hired to develop their proposals under the names of Red ( Intermetrics led by Benjamin Brosgol), Green ( Honeywell , led by Jean Ichbiah ), Blue ( SofTech , led by John Goodenough) and Yellow ( SRI International , led by Jay Spitzen). In April 1978, after public scrutiny,

590-623: A series of simply Interface Age benchmarks (originally designed for BASIC programs) is documented in an Australian Computer Society, MICSIG, paper presented at the National Conference on Microcomputer Software, Canberra , ACT presented in June 1982, along with a wide range of other contemporary machines and compilers, including Z80 systems supported by the 9511 APU chip hosted in the Digicomp S-100 Microengine system that he used. At

649-612: A significant business in the defense, aerospace, or related industries, also offered Ada compilers and tools on their platforms; these included Concurrent Computer Corporation , Cray Research, Inc. , Digital Equipment Corporation , Harris Computer Systems , and Siemens Nixdorf Informationssysteme AG . In 1991, the US Department of Defense began to require the use of Ada (the Ada mandate ) for all software, though exceptions to this rule were often granted. The Department of Defense Ada mandate

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708-499: A tasking model that was different from what most real-time programmers were used to. Because of Ada's safety-critical support features, it is now used not only for military applications, but also in commercial projects where a software bug can have severe consequences, e.g., avionics and air traffic control , commercial rockets such as the Ariane 4 and 5 , satellites and other space systems, railway transport and banking. For example,

767-413: A variable. However, since Ada 2012, functions are not required to be pure and may mutate their suitably declared parameters or the global state. Example: Package specification (example.ads) Package body (example.adb) This program can be compiled, e.g., by using the freely available open-source compiler GNAT , by executing Packages, procedures and functions can nest to any depth, and each can also be

826-424: A whole block of code therefore requires the prefixing of each line (or column) individually with "--". While this clearly denotes disabled code by creating a column of repeated "--" down the page, it also renders the experimental dis/re-enablement of large blocks a more drawn-out process in editors without block commenting support. The semicolon (";") is a statement terminator , and the null or no-operation statement

885-502: A whole during its early days. Its backers and others predicted that it might become a dominant language for general purpose programming and not only defense-related work. Ichbiah publicly stated that within ten years, only two programming languages would remain: Ada and Lisp . Early Ada compilers struggled to implement the large, complex language, and both compile-time and run-time performance tended to be slow and tools primitive. Compiler vendors expended most of their efforts in passing

944-627: Is null; . A single ; without a statement to terminate is not allowed. Unlike most ISO standards, the Ada language definition (known as the Ada Reference Manual or ARM , or sometimes the Language Reference Manual or LRM ) is free content . Thus, it is a common reference for Ada programmers, not only programmers implementing Ada compilers. Apart from the reference manual, there is also an extensive rationale document which explains

1003-705: Is a multi-chip 16-bit microprocessor introduced by Western Digital in 1975 and produced through the early 1980s. Used in the Pascal MicroEngine , the WD16 processor in the Alpha Microsystems AM-100, and the DEC LSI-11 microcomputer, a cost-reduced and compact implementation of the DEC PDP-11 . There are three types of chips in the chip-set: The chips use a 3.3 MHz four phase clock and three power supply voltages (+5V, +12V, and -5V), as required by

1062-526: Is designed for developing very large software systems. Ada packages can be compiled separately. Ada package specifications (the package interface) can also be compiled separately without the implementation to check for consistency. This makes it possible to detect problems early during the design phase, before implementation starts. A large number of compile-time checks are supported to help avoid bugs that would not be detectable until run-time in some other languages or would require explicit checks to be added to

1121-413: Is high-level and type-safe. Ada has no generic or untyped pointers ; nor does it implicitly declare any pointer type. Instead, all dynamic memory allocation and deallocation must occur via explicitly declared access types . Each access type has an associated storage pool that handles the low-level details of memory management; the programmer can either use the default storage pool or define new ones (this

1180-474: Is not based on the internal representation of the type but on describing the goal which should be achieved. This allows the compiler to determine a suitable memory size for the type, and to check for violations of the type definition at compile time and run time (i.e., range violations, buffer overruns, type consistency, etc.). Ada supports numerical types defined by a range, modulo types, aggregate types (records and arrays), and enumeration types. Access types define

1239-603: Is particularly relevant for Non-Uniform Memory Access ). It is even possible to declare several different access types that all designate the same type but use different storage pools. Also, the language provides for accessibility checks , both at compile time and at run time, that ensures that an access value cannot outlive the type of the object it points to. Though the semantics of the language allow automatic garbage collection of inaccessible objects, most implementations do not support it by default, as it would cause unpredictable behaviour in real-time systems. Ada does support

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1298-404: Is structured into standard statements. All standard constructs and deep-level early exit are supported, so the use of the also supported " go to " commands is seldom needed. Among the parts of an Ada program are packages, procedures and functions. Functions differ from procedures in that they must return a value. Function calls cannot be used "as a statement", and their result must be assigned to

1357-585: The N-channel silicon gate process then available at Western Digital. Internally the MCP-1600 is a (relatively fast) 8-bit processor that can be micro-programmed to emulate a 16-bit CPU. All byte operations execute in one clock period; word operations and branches take two clocks. Up to four MICROMs are supported, but usually two or three could hold the needed microprogram for a processor. The register file consists of 26 8-bit registers. Ten may be addressed directly by

1416-748: The Primary Flight Control System , the fly-by-wire system software in the Boeing 777 , was written in Ada, as were the fly-by-wire systems for the aerodynamically unstable Eurofighter Typhoon , Saab Gripen , Lockheed Martin F-22 Raptor and the DFCS replacement flight control system for the Grumman F-14 Tomcat . The Canadian Automated Air Traffic System was written in 1 million lines of Ada ( SLOC count). It featured advanced distributed processing ,

1475-551: The Soviet Union under the designation KR581IK1 and KR581IK2 ( Russian : КР581ИК1 and КР581ИК2 ). The Soviet 581 series included other members of the MCP-1600 family as well. cp16sim is an open source MCP-1600 simulator. Written in C , it emulates the MCP-1600 processor and its PTA executing the code found on the WD9000 Pascal Microengine processor. As of 2016 it is unfinished. "It works well enough to execute

1534-540: The US Department of Defense (DoD) became concerned by the number of different programming languages being used for its embedded computer system projects, many of which were obsolete or hardware-dependent, and none of which supported safe modular programming. In 1975, a working group , the High Order Language Working Group (HOLWG), was formed with the intent to reduce this number by finding or creating

1593-1170: The United States Department of Defense (DoD) from 1977 to 1983 to supersede over 450 programming languages used by the DoD at that time. Ada was named after Ada Lovelace (1815–1852), who has been credited as the first computer programmer. Ada was originally designed for embedded and real-time systems. The Ada 95 revision, designed by S. Tucker Taft of Intermetrics between 1992 and 1995, improved support for systems, numerical, financial, and object-oriented programming (OOP). Features of Ada include: strong typing , modular programming mechanisms (packages), run-time checking , parallel processing ( tasks , synchronous message passing , protected objects, and nondeterministic select statements ), exception handling , and generics . Ada 95 added support for object-oriented programming , including dynamic dispatch . The syntax of Ada minimizes choices of ways to perform basic operations, and prefers English keywords (such as "or else" and "and then") to symbols (such as "||" and "&&"). Ada uses

1652-536: The WD16 processor used by Alpha Microsystems (each using different microcode). One of the well regarded systems was the S-100 bus based dual processor cards developed by Digicomp Research of Ithaca, NY. These cards deserve an entry on their own, as they survived the demise of the WD single-board system and delivered reliable performance at up to 2.5 Mhz . A typical configuration was a Digicomp dual processor board set, containing

1711-481: The compiler can in some cases detect potential deadlocks. Compilers also commonly check for misspelled identifiers , visibility of packages, redundant declarations, etc. and can provide warnings and useful suggestions on how to fix the error. Ada also supports run-time checks to protect against access to unallocated memory, buffer overflow errors, range violations, off-by-one errors , array access errors, and other detectable bugs. These checks can be disabled in

1770-601: The compiler to find errors in favor of runtime errors. Ada is an international technical standard , jointly defined by the International Organization for Standardization (ISO), and the International Electrotechnical Commission (IEC). As of May 2023 , the standard, called Ada 2022 informally, is ISO/IEC 8652:2023. Ada was originally designed by a team led by French computer scientist Jean Ichbiah of Honeywell under contract to

1829-649: The Ada-Europe 2012 conference in Stockholm, the Ada Resource Association (ARA) and Ada-Europe announced the completion of the design of the latest version of the Ada language and the submission of the reference manual to the ISO/IEC JTC 1/SC 22 /WG 9 of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) for approval. ISO/IEC 8652:2012 (see Ada 2012 RM )

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1888-575: The GNAT Compiler is part of the GNU Compiler Collection . Work has continued on improving and updating the technical content of the Ada language. A Technical Corrigendum to Ada 95 was published in October 2001, and a major Amendment, ISO/IEC 8652:1995/Amd 1:2007 was published on March 9, 2007, commonly known as Ada 2005 because work on the new standard was finished that year. At

1947-541: The MicroEngine was the AVAB Viking lighting control system, which used the Modular MicroEngine boards along with some custom hardware. A group led by David A. Fisher developed the third validated Ada compiler using the Modular MicroEngine. for version 17.1 of the Ada verification system then in use. This compiler was later transferred to mainframe/minicomputers under the name of GenSoft Ada, and ran in an emulator of

2006-631: The Microengine under the MicroEngine-specific UCSD 3 operating system. Copies of the Prime computer version are known to be held by M R Wigan, who also holds a zero price licence for the full MicroEngine Ada system and UCSD 3 Operating system used for the Modular Microengine, as well as the three Modular MicroEngines used to create the 17.1 Ada, and all the development 8" floppy discs. Ada was

2065-627: The Red and Green proposals passed to the next phase. In May 1979, the Green proposal, designed by Jean Ichbiah at Honeywell, was chosen and given the name Ada—after Augusta Ada King, Countess of Lovelace, usually known as Ada Lovelace . This proposal was influenced by the language LIS that Ichbiah and his group had developed in the 1970s. The preliminary Ada reference manual was published in ACM SIGPLAN Notices in June 1979. The Military Standard reference manual

2124-610: The UCSD Pascal III version of the operating system tuned specifically for the WD chipset - once the Microengine had booted the ram-disc was available. A software facility within UCSD Pascal allowed the system to copy the entire operating system to the ram disc and transfer control to it. This sped it up remarkably. This use of a Z80 BIOS to handle all the devices, allowed the use of a range of floppy discs , I/O boards and hard disk controllers . The performance of this Microengine on

2183-572: The acceptance of a new standard version, the previous one becomes withdrawn. The other names are just informal ones referencing a certain edition. Other related standards include ISO/IEC 8651 -3:1988 Information processing systems—Computer graphics—Graphical Kernel System (GKS) language bindings—Part 3: Ada . Ada is an ALGOL -like programming language featuring control structures with reserved words such as if , then , else , while , for , and so on. However, Ada also has many data structuring facilities and other abstractions which were not included in

2242-452: The basic arithmetical operators "+", "-", "*", and "/", but avoids using other symbols. Code blocks are delimited by words such as "declare", "begin", and "end", where the "end" (in most cases) is followed by the identifier of the block it closes (e.g., if ... end if , loop ... end loop ). In the case of conditional blocks this avoids a dangling else that could pair with the wrong nested if-expression in other languages like C or Java. Ada

2301-590: The date of its adoption by ISO. There is also a French translation; DIN translated it into German as DIN 66268 in 1988. Ada 95 , the joint ISO/IEC/ANSI standard ISO/IEC 8652:1995 was published in February 1995, making it the first ISO standard object-oriented programming language. To help with the standard revision and future acceptance, the US Air Force funded the development of the GNAT Compiler . Presently,

2360-725: The first few dozen p-code instructions of the ACD PDQ-3 boot ROM before going into the weeds." It is released under the GNU General Public License version 3. Ada (programming language) Ada is a structured , statically typed , imperative , and object-oriented high-level programming language , inspired by Pascal and other languages. It has built-in language support for design by contract (DbC), extremely strong typing , explicit concurrency, tasks, synchronous message passing, protected objects, and non-determinism . Ada improves code safety and maintainability by using

2419-523: The hard disk bootstrap code) only very small Ada programs could be compiled. At one point in the compilation the compiler swapped the operating system out to disk, to gain just a little more room. "A(da" replaced "A(ssmble" on the main command menu. No native assembler was available or needed. This UCSD-based Ada was later redeveloped for the Sage 4 by TeleSoft in San Diego. MCP-1600 The MCP-1600

Pascal MicroEngine - Misplaced Pages Continue

2478-487: The interest of runtime efficiency, but can often be compiled efficiently. It also includes facilities to help program verification . For these reasons, Ada is sometimes used in critical systems, where any anomaly might lead to very serious consequences, e.g., accidental death, injury or severe financial loss. Examples of systems where Ada is used include avionics , air traffic control , railways , banking, military and space technology . Ada's dynamic memory management

2537-459: The internal 8-bit micromachine to create application-specific extensions to the instruction set. The WCS is a quad Q-Bus board with a ribbon cable connecting to an open MCP-1600 microcode ROM socket. In March 1976, it was announced that National Semiconductor would second-source the MCP-1600. It is unclear whether any were produced by National. A clone of the CP1611 and CP1621 was manufactured in

2596-465: The language design and the use of various language constructs. This document is also widely used by programmers. When the language was revised, a new rationale document was written. One notable free software tool that is used by many Ada programmers to aid them in writing Ada source code is the GNAT Programming Studio, and GNAT which is part of the GNU Compiler Collection . In the 1970s

2655-598: The logical outermost block. Each package, procedure or function can have its own declarations of constants, types, variables, and other procedures, functions and packages, which can be declared in any order. A pragma is a compiler directive that conveys information to the compiler to allow specific manipulating of compiled output. Certain pragmas are built into the language, while others are implementation-specific. Examples of common usage of compiler pragmas would be to disable certain features, such as run-time type checking or array subscript boundary checking, or to instruct

2714-578: The macroinstruction. John Wallace was the Project Manager and designed the 1621, Mike Briner designed the 1611, and later became a Senior VP at Silicon Storage Technology . Bill Pohlman was the design engineering manager and he later was Project Manager for the Intel 8086 processor. Microcode could be developed using a DEC LSI-11 computer with the KUV11-AA Writable Control Store (WCS) option. This option allowed programming of

2773-684: The massive, language-conformance-testing, government-required Ada Compiler Validation Capability (ACVC) validation suite that was required in another novel feature of the Ada language effort. The first validated Ada implementation was the NYU Ada/Ed translator, certified on April 11, 1983. NYU Ada/Ed is implemented in the high-level set language SETL . Several commercial companies began offering Ada compilers and associated development tools, including Alsys , TeleSoft , DDC-I , Advanced Computer Techniques , Tartan Laboratories , Irvine Compiler , TLD Systems , and Verdix . Computer manufacturers who had

2832-477: The microinstruction (Rx), four may be addressed either directly or indirectly (Rx/Gx), and the remaining 12 may be addressed only indirectly (Gx). Indirect addressing is via a 3-bit G register which is usually loaded with the register field of the PDP-11 instruction. The most significant feature of the MCP-1600 is its Programmable Translation Array (PTA). The PTA serves to generate new microinstruction fetch addresses as

2891-457: The only other full programming language available. John Lloyd of the University of Melbourne created an early version of his Prolog for this system and both Basic and Fortran 77 compilers were ported from other UCSD P-system implementations at various times, but not widely distributed. Due to limited memory (62K 16-bit words , the last 2K words being reserved for memory-mapped I/O and PROM for

2950-540: The original ALGOL 60 , such as type definitions , records , pointers , enumerations . Such constructs were in part inherited from or inspired by Pascal . A common example of a language's syntax is the Hello world program : (hello.adb) This program can be compiled by using the freely available open source compiler GNAT , by executing Ada's type system is not based on a set of predefined primitive types but allows users to declare their own types. This declaration in turn

3009-463: The same size as signal traces , very few capacitors ), required a large number of modifications, and even then did not work reliably. A couple of years would pass after introduction before a well-engineered MicroEngine was available. Between a damaged reputation and the introduction of the IBM PC , in the end the MicroEngine was only modestly successful. A further example of a commercial product based on

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3068-402: The same type, so the expression is illegal. Types can be refined by declaring subtypes : Types can have modifiers such as limited, abstract, private etc. Private types do not show their inner structure; objects of limited types cannot be copied. Ada 95 adds further features for object-oriented extension of types. Ada is a structured programming language, meaning that the flow of control

3127-402: The source code. For example, the syntax requires explicitly named closing of blocks to prevent errors due to mismatched end tokens. The adherence to strong typing allows detecting many common software errors (wrong parameters, range violations, invalid references, mismatched types, etc.) either during compile-time, or otherwise during run-time. As concurrency is part of the language specification,

3186-411: The time of introduction, the only competitors were 8-bit processors (mainly Intel 8080 , Z80, and MOS Technology 6502 based systems). The MicroEngine could compile Pascal source code in a fraction of the time (typically about 1/10) required by contemporaries. Fast compilation made the MicroEngine especially nice as a developer's machine, and the inclusion of a semaphore primitive in the microcode

3245-410: Was approved on December 10, 1980 (Ada Lovelace's birthday), and given the number MIL-STD-1815 in honor of Ada Lovelace's birth year. In 1981, Tony Hoare took advantage of his Turing Award speech to criticize Ada for being overly complex and hence unreliable, but subsequently seemed to recant in the foreword he wrote for an Ada textbook. Ada attracted much attention from the programming community as

3304-538: Was effectively removed in 1997, as the DoD began to embrace commercial off-the-shelf (COTS) technology. Similar requirements existed in other NATO countries: Ada was required for NATO systems involving command and control and other functions, and Ada was the mandated or preferred language for defense-related applications in countries such as Sweden, Germany, and Canada. By the late 1980s and early 1990s, Ada compilers had improved in performance, but there were still barriers to fully exploiting Ada's abilities, including

3363-428: Was first published in 1980 as an ANSI standard ANSI/ MIL-STD 1815 . As this very first version held many errors and inconsistencies , the revised edition was published in 1983 as ANSI/MIL-STD 1815A. Without any further changes, it became an ISO standard in 1987. This version of the language is commonly known as Ada 83 , from the date of its adoption by ANSI, but is sometimes referred to also as Ada 87 , from

3422-582: Was particularly useful for multi user enhancements, which were developed in Melbourne for the Canberra Australia-based Ortex Company, extended to be a multiuser system and often sold with a bundled pharmacy management system, also delivered on the Sage IV computers under UCSD Pascal IV and enabled as a multiuser system using the Sage multiuser BIOS rather than by extending UCSD Pascal IV to add

3481-520: Was published in December 2012, known as Ada 2012 . A technical corrigendum, ISO/IEC 8652:2012/COR 1:2016, was published (see RM 2012 with TC 1 ). On May 2, 2023, the Ada community saw the formal approval of publication of the Ada ;2022 edition of the programming language standard. Despite the names Ada 83, 95 etc., legally there is only one Ada standard, the one of the last ISO/IEC standard: with

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