Task Swapping Laws

These laws are based on the Macintosh System 7 environment and will hopefully be used in ADOS or K-OS for the Atari 8-bit platform (or Atari Sweet-16-based machines).

Terms:

• CLI: Command Line Interface
  An environment where the user tells the interface to execute programs by giving it their name (and location) and the parameter list to send to the program.
  Examples:
  • MS-DOS
  • Unix
  • SpartaDOS
• GUI: Graphical User Interface
  An environment using bitmap- or text-based graphics, usually using:
  • Windows
  • Icons
  • A pointer (usually mouse-driven)
  • Menu-bars
• OS: Operating System
  A set of routines which are installed in hardware (ROM) or loaded at boot-up (stored on disk and transferred to RAM).
• F-Man: File manager
  A program which presents the user with some sort of access to his/her files and applications. In a GUI, this would of course be a windowed system.
  Examples:
  • MS Windows 3.1 Program Manager
  • MS Windows 3.1 File Manager
  • Macintosh Finder
• E-Man: Environment manager (or "shell")
  A program or OS routine(s) which bridges the space between the user interface (CLI, GUI, etc.) and the programs.
  The E-Man would place commands and parameters in a list and then jump to or execute a program. The program would then act accordingly.
  Examples:
  • MS Windows 3.1 File Manager: File types (depending on thier extender (.TXT, .GIF, .WAV, etc.)) would be associated to certain programs (Text Editor, Graphic Viewer, Sound Player, etc.). When the user tells File Manager to open a file, it would launch the application and tell it to open that specified file.
  • Finder: (Acts the same as Windows 3.1 File Manager except it determines type and associated program as "resource" data and is almost never determined by the user.)
  • Unix: Unix converts (variables, wild-carded file lists, etc.) the command and parameters and executes it.

Opening an Application

This can also be performed from within other non-F-man applications. A C-compiler might have other "external" programs it uses such as editors, linkers, etc.

If the application is already "running"

If the application isn't "running"

1. Load it into memory
2. Jump into it
3. Tell it to do its installation routine
4. And tell it to do its default load-up action (ask the user to open an existing file; create a new file; do nothing; etc.)

Opening a File(s)

Non F-man and P-man programs can also perform the task of loading other applications.

For example, a World Wide Web browser can jump into a text processor to view HTML source files or into an MPEG player to play MPEG animations.

If the file's application is unknown (N/A if "drop" is performed)

If the file's application is loaded or not loaded

1. Load or jump to the application
2. Tell the application to open the file(s)

Special Case: Direct Returning from an Application

Another example is say 3 text files and 3 graphics files are selected and then "opened" (double clicked). The F-man would load the text editor, tell it to load the text files and also tell it to return to the F-man (or E-man, assuming the F-man would be piping a batch of commands to the E-man; E-man is useful for smaller machines because the F-man would be a large, complex program, and the E-man would simply be the actual program launching routines, without the user interface). Once the F-man has been reloaded or jumped back into, it would then load the graphic viewer, tell it to load the graphics files, and either stay in the graphic viewer, or return to the F-man or E-man and it would choose which application to load.

Exit (or Return)

Special Case: Auto-quitting an Application

It's also useful for the F-man to be able to see what programs are idle (without open windows or files) and let you quit them when you try to open a new application but are lacking the memory to do so.

Quit