Cannot Use /2 Switch for Dual-Monitor Debugging on PS/2

MS-DOS                             | OS/2                | WINDOWS

The information in this article applies to:

• Microsoft CodeView for MS-DOS, versions 2.2, 3.0, 3.11, 3.14, 4.0, 4.01, 4.05, and 4.1
• Microsoft CodeView for OS/2, versions 2.2, 3.0, 3.11, 3.12, and 3.5
• Microsoft CodeView for Windows, versions 3.0, 3.05, 3.06, 3.07, 4.0, 4.01, and 4.1
• Microsoft CodeView for Win32s, version 4.25

To use the /2 switch to enable dual-monitor debugging in CodeView, your computer must be equipped with a monochrome display (MDA) and a color display (CGA/EGA/VGA). Monochrome display adapters are not generally available for the IBM PS/2 computers because they come with built-in VGAs or MDAs, but not both. This means that dual-monitor debugging is usually not possible on a PS/2 system.

This is a hardware issue and not a CodeView limitation; therefore, when hardware vendors start selling MDAs that can be added to PS/2 systems with built-in VGAs, then CodeView dual-monitor debugging will be available on the PS/2.