When limited memory is a problem, you should consider using an overlay manager. A full-featured overlay manager is offered as the basis for a discussion of design and debugging considerations of overlays. Then suggestions are made on how to modify this overlay manager for your programming requirements.
Extended Memory Specification 2.x: Taking Advantage
of the 80286 Protected Mode
The Extended Memory Specification 2.x (XMS) provides programmers with a standard method for accessing
extended memory, allowing them to make use of the 80286 protected mode. The XMS functions are
examined and a sample DOS program shows how XMS calls can be used to store data in extended memory.
Exploring the Key Functions of the OS/2 Keyboard
and Mouse Subsystems
The OS/2 keyboard (KBD) and mouse (MOU) subsystems offer a rich set of functions that allow an
application to obtain user input. This article examines the core functions of these subsystems and applies
them in a sample program that incorporates KBD and MOU functions in a multithreaded application.
Everything You Always Wanted to Know About
the MS-DOS EXEC FunctionÉ
Programs use the powerful MS-DOS EXEC function to bring COM and EXE files from disk into memory
and execute them. EXEC is frequently used to run subsidiary programs or a second copy of
COMMAND.COM. This article examines EXEC and provides sample programs that demonstrate its uses.
Customizing a Microsoft Windows Dialog Box
with New Control Classes
Controls, child windows belonging to a predefined class and having a predefined behaviors, can be used by
any application or dialog box to customize aspects of Microsoft Windows. This article provides a step-by-
step guide to creating the SELECT class, an alternative to the listbox.
Techniques for Calling OS/2 System Services From
OS/2 compatibility has furthered BASIC's emergence as a professional language. This article explores both
direct calling of OS/2 services by BASIC programs and the use of an assmebly language interface between
BASIC and the OS/2 operating systems. Sample utilites demonstrate these methods.
Pointers 101: Understanding and Using Pointers in the
Using pointers correctly is one of the most difficult aspects of the C language for programmers to master.
The terminology can be confusing and much of the explanatory material found in books and articles is
incomplete. This is the first article in a series designed to give you a solid cognizance of pointers.