How to Run System Diagnostics in MS-DOS 6.22

In MS-DOS 6.22, the built-in utility that provides text-based menu access to comprehensive system diagnostics is Microsoft Diagnostics, launched using the command MSD. This utility allows users and technicians to inspect low-level hardware configurations, allocated memory blocks, installed drivers, and system resource assignments without needing third-party software. The following guide explains how to access Microsoft Diagnostics, navigate its text interface, and utilize its reporting features.

Launching Microsoft Diagnostics

Microsoft Diagnostics is included as an external command located in the default DOS directory (C:\DOS\MSD.EXE). To start the utility:

  1. Boot the computer into MS-DOS 6.22 to reach the command prompt.
  2. Type MSD and press Enter.

The program initializes a full-screen, text-based user interface (TUI) built using character-cell graphics. Navigation is possible using either a serial/bus mouse or the keyboard. Each diagnostic category displays a highlighted letter, which acts as a hotkey to immediately open that section (for example, pressing P opens the Computer/Processor screen).

Available Diagnostic Information

The main menu of MSD provides instant access to several key hardware and software components:

  • Computer: Displays the system manufacturer, BIOS version, BIOS date, processor type (e.g., 80386, 80486, Pentium), and the presence of a math coprocessor.
  • Memory: Provides a map of conventional, extended (XMS), and expanded (EMS) memory, detailing base memory usage and Upper Memory Blocks (UMBs).
  • Video: Identifies the display adapter type (VGA, EGA, CGA), video BIOS manufacturer, and current display mode.
  • Network: Detects active network client software, network operating systems, and adapter configurations if network drivers are loaded.
  • OS Version: Shows the exact DOS version, operating environment, and DOS location in memory (e.g., loaded high via DOS=HIGH).
  • Mouse: Reports driver version, mouse hardware type, and interrupt settings.
  • Disk Drives: Lists all detected local and logical drives, total storage capacity, and available free space.
  • LPT and COM Ports: Inspects parallel and serial ports, showing active port addresses and communication settings.
  • IRQ Status: Displays hardware interrupt request line assignments (IRQ 0–15), identifying conflicting hardware devices sharing lines.
  • TSR Programs & Device Drivers: Lists all Terminate-and-Stay-Resident programs and drivers loaded via CONFIG.SYS or AUTOEXEC.BAT, along with their specific memory addresses.

Generating Reports and Command Switches

MSD includes switches for generating system reports directly from the DOS command line, making it useful for automated scripts or troubleshooting systems with faulty displays:

  • MSD /B — Runs the diagnostic interface in black-and-white mode, which resolves readability issues on monochrome or LCD displays.
  • MSD /I — Bypasses hardware detection during launch to prevent the system from freezing if faulty hardware is present.
  • MSD /F filename.txt — Automatically prompts for customer information and generates a complete, plain-text diagnostic log to the specified file.
  • MSD /P filename.txt — Generates a comprehensive technical report directly to the specified file without prompting for user input.