MEMORY TERMS

Address -- The number, assiged to a byte, that indicates its position in the memory; the first byte has an address of 0.

Low end of memory -- In the memory, those bytes close to byte 0.

High end of memory -- In the memory, those bytes close to the byte with the highest address.

Most significant bits -- The leftmost bits within a byte.

High-order bits -- See Most significant bits.

Least significant bits-- The rightmost bits within a byte.

Low-order bits -- See Least significant bits.

Boundary -- An address that is a multiple of a specific number.

Word boundary-- An address that is a multiple of 2.

Aligned (to a boundary) -- Describes a byte whose address is at a specified boundary.

Doubleword boundary -- An address that is a multiple of 4.

Quadword boundary -- An address that is a multiple of 8.

Paragraph boundary-- An address that is a multiple os 16.

Primary memory -- Memory that the processor can work with directly.

Secondary memory-- Memory that the processor cannot work with directly. Secondary memory resides on the disks.

Read-only memory -- Primary memory that can be read but not changed.

ROM -- Abbreviation for "read-only memory."

Random-access memory -- Primary memory, also called read-write memory, that can be both read and changed.

RAM-- Abbreviation for "random-access memory."

Read-write memory -- See Random access memory.

Register -- One of 15 words of read-write memory built into the processor.

Accumulator -- Another name for the AX register.

Base register -- Another name for the BX or BP registers.

Count register -- Another name for the CX register.

Data register-- Another name for the DX register.

Load -- To copy data into a register.

Store -- To copy data from a register.

Stack -- A data structure that allows you to store and recall data in a last-in, first-out manner.

Empty-- Describes a stack that contains no data.

Push -- To store data on the stack.

Pop-- To recall data from the stack.

Top (of the stack)-- The location in the stack that contains the last item of data that was pushed.

Procedure-- A self-contained module, also called a function or a subroutine, that is part of a larger program.

Function -- See Procedure.

Subroutine -- See Procedure.

Call (a procedure) -- To begin executing a procedure.

Return (from a procedure) -- When a procedure is finished, to continue executing the program that called the procedure.

Return address -- The location to which a procedure returns when it finishes executing.