8086 :: Simplified Segment Directives

.model (memory model)

Memory model	Description
Tiny	Code and data together may not be greater than 64K
Small	Neither code nor data may be greater than 64K
Medium	Only the code may be greater than 64K
Compact	Only the data may be greater than 64K
Large	Both code and data may be greater than 64K
Huge	All available memory may be used for code and data

.stack

The .stack directive sets the size of the program stack, which may be any size up to 64K. This segment is addressed by SS and SP registers.

.code

The .code directive identifies the part of the program that contains instructions. This segment is addressed by CS and IP registers.

.data

All variables are defined in this segment area.