Further Details
For any given personal computer, mainframe, embedded system, and game console, both past and present, at least one – possibly dozens – of assemblers have been written. For some examples, see the list of assemblers.
On Unix systems, the assembler is traditionally called as, although it is not a single body of code, being typically written anew for each port. A number of Unix variants use GAS.
Within processor groups, each assembler has its own dialect. Sometimes, some assemblers can read another assembler's dialect, for example, TASM can read old MASM code, but not the reverse. FASM and NASM have similar syntax, but each support different macros that could make them difficult to translate to each other. The basics are all the same, but the advanced features will differ.
Also, assembly can sometimes be portable across different operating systems on the same type of CPU. Calling conventions between operating systems often differ slightly or not at all, and with care it is possible to gain some portability in assembly language, usually by linking with a C library that does not change between operating systems. An instruction set simulator can process the object code/ binary of any assembler to achieve portability even across platforms with an overhead no greater than a typical bytecode interpreter. This is similar to use of microcode to achieve compatibility across a processor family.
Some higher level computer languages, such as C and Borland Pascal, support inline assembly where sections of assembly code, in practice usually brief, can be embedded into the high level language code. The Forth language commonly contains an assembler used in CODE words.
An emulator can be used to debug assembly-language programs.
Read more about this topic: Assembly Language
Famous quotes containing the word details:
“Patience is a most necessary qualification for business; many a man would rather you heard his story than granted his request. One must seem to hear the unreasonable demands of the petulant, unmoved, and the tedious details of the dull, untired. That is the least price that a man must pay for a high station.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (1694–1773)
“Different persons growing up in the same language are like different bushes trimmed and trained to take the shape of identical elephants. The anatomical details of twigs and branches will fulfill the elephantine form differently from bush to bush, but the overall outward results are alike.”
—Willard Van Orman Quine (b. 1908)