Program Segment Prefix

As a program segment (English Program Segment Prefix, PSP ) is defined as the first 256 bytes of a charged MS- DOS program. The PSP is not included in the executable EXE or COM files, but is created when the program is loaded by the operating system. The first half of the PSPs includes various information for the operating system, in particular for handling a plurality of ( sequentially ) executed programs. In the second half there is the command line (command tail, without the actual name of the program ).

Structure

Other areas of the PSPs are used by operating system extensions or some TSR programs.

Example Program

This program displays the command line from his PSP to: (Com - file, written in assembly language )