Appendix A
GLOSSARY OF TERMS

ASCII

An international standard for character codes to promote the portability of character string data between different computer systems.

Assembler

A compiler that takes an Assembly language source code file and outputs a machine language object code file.

BIOS

The basic input output system software provided by the computer to handle hardware interface.

Bug

A condition when the computer system does not operate according to specifications.

Conditional Assembly

A method of using a compiler directive to either compile or ignore a section of code. A variable used to decide if code is compiled or not can be set just before or at compile time. This feature is used by programmers for many different reasons. A common use of conditional assembly is to generate special code that is used only for debugging versions of a program.

Contiguous

A block of computer memory where a program has control of all memory variables from the start of the memory area to the end of the memory area. This means that no other program can use any segment of the memory inside of a contiguous memory area of a program.

CPU

The central processing unit of a computer system. This is the hardware unit that executes a computer program.

Debugger

A tool that may be hardware or software that is used to aid in finding computer bugs.

DOS

The disk operating system of a computer system.

Macro

In some ways like a subroutine except a macro is expanded in the code each time the macro is referenced, which removes the need for call and return instructions. A macro executes faster than a subroutine but requires more memory space if referenced more than once. If you have a subroutine that is only referenced once, you may want to convert it into a macro to speed up the code by removing the call and return instructions.

MASM

Microsoft Macro Assembler acronym.

Mnemonic

The Assembly language instruction names are often referenced as the instruction mnemonics. Example: MOV is the mnemonic for the move instruction.

Operand

The data that is used for a computer instruction.

Peripheral

A device that is attached to a computer system such as a printer, modem, etc.

Register

A special memory location inside a CPU. There are many registers inside a standard CPU. Many of these registers serve specific functions for instruction executions and CPU operations.