DOS SFN Family
- Display - (videocard and monitor)
- Disk - (floppydisk, hard drive, CD-ROM, etc.)
- Input - (keyboard, mouse, modem, etc.)
- Output - (printer and sound)
- File - (data file manipulation)
- Batch - (batch file tools)
- MOTD - (messagae-of-the-day display)
- Miscellaneous - (program manipulation and "Utlity Suites")
From its inception, DOS was a modular operating system. All DOS provides are low level I/O services. Everything else was supposed to be provided through a User Interface loaded on top of DOS. The replaceable (with 4DOS for example) user interface bundled with the OS by Microsoft, was a stripped-down Textual User Interface called 'command.com', which uses a Command Line for input. Even this user interface was itself designed to be modular, as 'command.com' only contains a minimal amount of internal commands, and an internal Batch File script Interpreter.
External Utilities are what gives the 'command.com' user interface its ability to perform real work. External utilities can be made to work together to perform tasks that would otherwise have to be done by hand (through direct keyboard input for example), or be an integral part of a program being executed. The Batch File Interpreter built into command.com allows sequential automation. No need to "mouse around". Just create a batch script, and the computer will do all the work for you.
Book: Advanced MS-DOS Batch File Programming (*.pdf)
* [For those on less capable computers, the above PDF has been divided below into five zipped sections]