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المصدر USA Today
العيب كان في ال software يارجال و لا تكذب و ليس تقارير الكونجرس السياسية الا حتي طلع السعودية مسئولة كوارث في حرب اليمن و قتل جمال خاشقجي.
و زي ماقولت ليك هما عوزين استمرار برنامج الباتريوت و تحقيق مبيعات و لذلك هيطلعوا القصة كدة.
موضوع خطأ ال software معروف للجميع
و هذا طبعا لا ينفي ان الباتريوت سلاح عظيم تنمي المصريين انه يكون بيحمي السد العالي
و ليس كما تهبد انت ان المصريين بيكرهوه علشان السعودية تمتلكة
ليس لديك تصريح لمشاهدة الرابط، فضلا قم ب تسجيل الدخول او تسجيل
The weapons developer hired an outside firm to help solve that problem. They published there finding, which is how I know this.
Software written for the military is written in the programming language named Ada. Named after Ada Lovelace, (10 December 1815 – 27 November 1852, she is considered the first computer programmer), it a DoD requirement. The problem is that most of the library software (used to interface with the low-level hardware) were created in the C language. The solution was to cross-compile the Ada code into C, and then link that code to the libraries to create the final code. A common practice at the time. This is what introduce the error.
The error was subtidal and defied the developers attempt to find it. The error has to do with how number are stored in computers. For REAL numbers (those that have a decimal point) the choice is SINGLE or DOUBLE precision. All of the code was written to use DOUBLE precision number. Buried deep within the code was a function that was only called once, when the missile went into terminal tracking mode. This function was incorrectly prototyped as a SINGLE. Either language would have flagged the errant code with at least a warning, but because the Ada code was cross complied into C, the error slipped in.
The C language allows programmers to use SINGLE where a DOUBLE is expected and promotes (widens) or demotes (narrows) the value as it passes the value to the function automatically. Since this happened at link time instead of compile time, this went unnoticed. The narrowing of the number from DOUBLE to SINGLE caused a loss of precision that the terminal phase used to fly its final intercept. The result was a miss when the number in its SINGLE form differed significantly from its DOUBLE form. It took the team that found it four months to find that error. This solved the core issue of the missile misses.
The missile also had another error which was widely reported. A bad calculation happened when computing time:
