Using Memory

Your computer can use up to 8MB of memory. This section describes how the memory in your computer works. Also be sure to see your operating system manual for complete information on memory management.

A computer’s memory is divided into three types: conventional, reserved, and extended. The following diagram shows the relationships between these types of memory and their addresses.

All memory in a computer is managed using addresses— numbers that describe the location of each byte of data. Each memory chip must have its own set of unique addresses so that the operating system knows where to store and find data.

Conventional memory is memory that MS-DOS recognizes and manages directly. The size of conventional memory is limited to 640KB and has addresses in the range 0 to 640KB.

Reserved memory is memory in the range 640KB to 1MB. The system enhances its performance by using 128KB of this memory as shadow RAM, and the remaining memory is available.

3-22 Using Your Computer