Assembly Language - Related Terminology

Related Terminology

• Assembly language or assembler language is commonly called assembly, assembler, ASM, or symbolic machine code. A generation of IBM mainframe programmers called it ALC for Assembly Language Code or BAL for Basic Assembly Language. Calling the language assembler might be considered potentially confusing and ambiguous, since this is also the name of the utility program that translates assembly language statements into machine code. However, this usage has been common among professionals and in the literature for decades. Similarly, some early computers called their assembler their assembly program.)
• The computational step where an assembler is run, including all macro processing, is termed assembly time. The assembler is said to be "assembling" the source code.
• The use of the word assembly dates from the early years of computers (cf. short code, speedcode).
• A cross assembler (see also cross compiler) is an assembler that is run on a computer or operating system of a different type from the system on which the resulting code is to run. Cross-assembling may be necessary if the target system cannot run an assembler itself, as is typically the case for small embedded systems. The computer on which the cross assembler is run must have some means of transporting the resulting machine code to the target system. Common methods involve transmitting an exact byte-by-byte copy of the machine code or an ASCII representation of the machine code in a portable format (such as Motorola or Intel hexadecimal) through a compatible interface to the target system for execution.
• An assembler directive or pseudo-opcode is a command given to an assembler "directing it to perform operations other than assembling instructions." Directives affect how the assembler operates and "may affect the object code, the symbol table, the listing file, and the values of internal assembler parameters." Sometimes the term pseudo-opcode is reserved for directives that generate object code, such as those that generate data.
• A meta-assembler is "a program that accepts the syntactic and semantic description of an assembly language, and generates an assembler for that language."