Civil Rights
Movements, leaders, victories and the continuing fight for equality.
Explore the people, places, events, achievements, struggles and stories that shaped our journey.
Movements, leaders, victories and the continuing fight for equality.
Innovation, patents, science, technology and world-changing contributions.
Pioneers, champions, Negro Leagues, records, activism and excellence.
Meet the people whose lives, choices and achievements shaped the journey.
Black towns, communities, institutions and places where history happened.
Moments that changed communities, movements, institutions and the nation.
Wilmington, North Carolina once had a thriving Black middle class and an elected interracial government. In 1898 white supremacists used violence to overthrow that government, kill Black residents and drive many others from the city.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
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In computing, object code or object module is the product of an assembler or compiler.[1]
In a general sense, object code is a sequence of statements or instructions in a computer language,[2] usually a machine code language (i.e., binary) or an intermediate language such as register transfer language (RTL). The term indicates that the code is the goal or result of the compiling process, with some early sources referring to source code as a "subject program".[3]
Object files can in turn be linked to form an executable file or library file. In order to be used, object code must either be placed in an executable file, a library file, or an object file.
Object code is a portion of machine code that has not yet been linked into a complete program. It is the machine code for one particular library or module that will make up the completed product. It may also contain placeholders or offsets, not found in the machine code of a completed program, that the linker will use to connect everything together. Whereas machine code is binary code that can be executed directly by the CPU, object code has the jumps and inter-module references partially parametrized so that a linker can fill them in. An object file is assumed to begin at a specific location in memory, often zero. It contains information on instructions that reference memory, so that the linker can relocate the code when combining multiple object files into a single program.
An assembler is used to convert assembly code into machine code (object code). A linker links several object (and library) files to generate an executable. Assemblers (and some compilers) can also assemble directly to machine code to produce executable files without the object intermediary step.[4]
Traditionally, the output of the compilation has been called object code or sometimes an object module.
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In computing, object code or object module is the product of an assembler or compiler. In a general sense, object code is a sequence of statements or instructions in a computer language, usually a machine code language (i.e., binary) or an intermediate language such as register transfer language (RTL). The term indicates that the code is the goal or result of the compiling process, with some early sources referring to source code as a "subject program".
An object file is a file that contains machine code or bytecode, as well as other data and metadata, generated by a compiler or assembler from source code during the compilation or assembly process. The machine code that is generated is known as object code. The object code is usually relocatable, and not usually directly executable. There are various formats for object files, and the same machine code can be packaged in different object file formats. An object file may also work like a shared library. The metadata that object files may include can be used for linking or debugging; it includes information to resolve symbolic cross-references between different modules, relocation information, stack unwinding information, comments, program symbols, and debugging or profiling information. Other metadata may include the date and time of compilation, the compiler name and version, and other identifying information. The term "object program" dates from at least the 1950s: A term in automatic programming for the machine language program produced by the machine by translating a source program written by the programmer in a language similar to algebraic notation. A linker is used to combine the object code into one executable program or library pulling in precompiled system libraries as needed.
Binary-code compatibility (binary compatible or object-code compatible) is a property of a computer system, meaning that it can run the same executable code, typically machine code for a general-purpose computer central processing unit (CPU), that another computer system can run. Source-code compatibility, on the other hand, means that recompilation or interpretation is necessary before the program can be run on the compatible system. For a compiled program on a general operating system, binary compatibility often implies that not only the CPUs (instruction sets) of the two computers are binary compatible, but also that interfaces and behaviours of the operating system (OS) and application programming interfaces (APIs), and the application binary interfaces (ABIs) corresponding to those APIs, are sufficiently equal, i.e. "compatible". A term like backward-compatible usually implies object-code compatibility. This means that newer computer hardware and/or software has (practically) every feature of the old, plus additional capabilities or performance. Older executable code will thus run unchanged on the newer product. For a compiled program running directly on a CPU under an OS, a "binary compatible operating system" primarily means application binary interface (ABI) compatibility with another system. However, it also often implies that APIs that the application depends on, directly or indirectly (such as the Windows API, for example), are sufficiently similar. Hardware (besides the CPU, such as for graphics) and peripherals that an application accesses may also be a factor for full compatibility, although many hardware differences are hidden by modern APIs (often partly supplied by the OS itself and partly by specific device drivers). In other cases, a general porting of the software must be used to make non-binary-compatible programs work. Binary compatibility is a major benefit when developing computer programs that are to be run on multiple OSes. Several Unix-based OSes, such as FreeBSD or NetBSD, offer binary compatibility with more popular OSes, such as Linux-derived ones, since most binary executables are not commonly distributed for such OSes. Most OSes provide binary compatibility, in each version of the OS, for most binaries built to run on earlier versions of the OS. For example, many executables compiled for Windows 3.1, Windows 95 or Windows 2000 can also be run on Windows XP or Windows 7, and many applications for DOS ran on much newer versions of Windows up to Windows 10 for as long as the NTVDM was supported.
A binary optimizer, also known as an object code optimizer, takes a program's object code or machine code either from a linked executable binary file, or from live program memory, and produces sections of optimized code, invoked through either redirection or code replacement, that is functionally equivalent yet more performant. Program speedup is a common optimization goal. Some are intended to modernize old binaries to take better advantage of updated hardware, while others lean heavily on profile-guided optimization and interprocedural optimization to deliver performance gains. Some utilize run-time mechanisms to introspectively improve performance using techniques similar to JIT compilers.
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →Shirley Chisholm, elected in 1968.