This book investigates the technical mechanisms and implementation strategies required to create memory-resident software, commonly known as terminate-and-stay-resident (TSR) programs, on the IBM PC architecture. Thomas A. Wadlow provides a structured approach to understanding how programs can remain active in system memory while allowing other applications to execute. The text focuses on the low-level interactions between software and the PC's BIOS and DOS interrupts, offering a framework for developers to manage system resources effectively. By examining the constraints of early PC hardware, the author establishes the necessary protocols for writing stable, non-conflicting background utilities.

Experts recognize this work as a technical manual for legacy systems programming, specifically targeting the DOS era of computing. Readers frequently note the high level of technical density, as the text assumes a strong foundational knowledge of assembly language and PC architecture.