PCs Before Windows: Experiencing MS-DOS

The Pre-Windows Era: Experiencing MS-DOS

Personal computers weren't initially equipped with the Windows operating system. Prior to Windows’ emergence, PCs typically utilized Microsoft's MS-DOS as their primary operating system.

The experience of using MS-DOS differed significantly from modern command-line interfaces. It wasn't simply analogous to utilizing a Linux terminal or the Command Prompt within a contemporary graphical desktop environment.

Limitations of the MS-DOS Environment

Numerous functionalities considered standard today were unavailable during the MS-DOS era. The computing landscape was fundamentally different.

Many features we now consider essential were simply not feasible within the constraints of the MS-DOS system. This shaped how users interacted with their computers.

A Different Approach to Computing

Users had to adapt to a completely different paradigm when working with MS-DOS. It required a deeper understanding of the system itself.

The command-line interface demanded precise commands and a memorization of system functions. This contrasted sharply with the point-and-click simplicity of later graphical user interfaces.

Experiencing Computing with DOS

The DOS operating system operated solely through a command-line interface, lacking the graphical windows common today. Upon powering on a computer, users were presented with a DOS prompt. Interaction required knowledge of specific commands entered at this prompt to initiate programs and utilize system utilities.

Navigating the operating system necessitated familiarity with a core set of commands. Switching between storage drives – such as accessing a floppy disk in drive A: – involved typing A: at the prompt followed by pressing the Enter key.

The CD command facilitated directory changes, while the DIR command displayed the files within the current directory. Executing a program simply required typing the name of its executable file at the prompt.

Consider the scenario of acquiring a new program on a floppy disk. The disk would be inserted into the floppy drive, accompanied by the characteristic sound of the drive reading the disk’s contents. The following commands would then be used:

• A:

• DIR

• SETUP or INSTALL (depending on the program’s installer name)

Installation typically involved extracting files to a folder on the computer’s hard drive. Due to size limitations, larger programs often required multiple floppy disks during installation. However, once installed, the program could be launched without the need for the disks.

Returning to the primary hard drive was achieved with the C: command. Subsequently, the CD command was used to navigate to the folder containing the installed program, and execution was initiated by typing the program’s name, such as PROGNAME.

File names were constrained by MS-DOS to a maximum of eight characters preceding a period, followed by a three-letter extension – for instance, PROGNAME.EXE.

Certain programs aimed to enhance usability for less experienced users. File managers, like Norton Commander, offered a graphical interface for file viewing and management, circumventing the need for command-line input. The visual style of most DOS programs centered around text-based screen arrangements.

The Single-Tasking Nature of MS-DOS

Contrary to popular belief, MS-DOS did not support true multitasking. The operating system operated on a principle of executing one process at a time. When an application was launched, it occupied the entire display.

Switching to a different program necessitated closing the currently active one and then issuing the command to initiate the new application. This process could be cumbersome for users accustomed to modern operating systems.

To mitigate this limitation, DOS introduced the "terminate and stay resident" (TSR) functionality. Programs designed with TSR capability could intercept specific keyboard combinations.

Activating the designated shortcut would effectively suspend the current program, retaining it in memory. Subsequently, the TSR program would load itself, giving the illusion of switching between applications.

However, it’s crucial to understand that TSR wasn't genuine multitasking. The suspended program wasn't actively running in the background. It was merely paused and readily available for reactivation.

DOS fundamentally remained a single-tasking environment, capable of executing only one program at any given moment. This contrasts sharply with contemporary shells, such as those found in Linux.

A Comparison with Modern Operating Systems

Modern operating systems, like Linux, offer robust multitasking capabilities. They allow for the concurrent execution of programs and services in the background.

Furthermore, these systems support features like multiple text-mode terminals, providing a level of flexibility and efficiency absent in DOS. The capabilities of DOS were considerably more limited in comparison.

Hardware Interaction in MS-DOS

Unlike modern operating systems, MS-DOS lacked standardized hardware support. Applications requiring direct hardware access – such as a game utilizing a sound card – were responsible for implementing this support themselves.

Developers creating DOS applications, like games, had to incorporate code for each sound card model their users might possess. Fortunately, the prevalence of Sound Blaster compatibility simplified this process somewhat.

Configuration for specific hardware was typically managed through a separate SETUP program for each application.

Real Mode Operation

Direct access to system resources, including memory and peripherals, necessitated operation in real mode, also known as real address mode.

In this mode, a single program could write to any memory location without any protective measures. This functionality was viable because only one program could execute at any given time.

The introduction of Windows 3.0 brought about protected mode, which imposed restrictions on the actions of running applications.

Compatibility Challenges Today

Many older DOS games remain incompatible with the modern Windows Command Prompt.

The Command Prompt operates in protected mode, while these games require the unrestricted access provided by real mode.

Consequently, emulators like DOSBox are essential for running numerous classic DOS games, providing the necessary real mode environment.

Early Windows Versions Operated as DOS Programs

The initial widely-used iterations of Windows, such as Windows 3.0 and 3.1, functioned as applications operating within the MS-DOS environment. Upon computer startup, users would first encounter the DOS prompt. Subsequently, they would input the 'WIN' command to initiate the Windows program.

This action would then present the familiar Windows 3-style desktop, commonly referred to as the Program Manager. It was also possible to configure the system to automatically launch Windows by incorporating the 'WIN' command into the AUTOEXEC.BAT file.