Exploring RISC OS on the Raspberry Pi

In spite of its similarities in appearance with popular operating systems like Linux, Mac OS X, or Windows, the paradigms and the operation of RISC OS are actually quite different from the other systems.

• The left mouse button in RISC OS is called Select; the right button is called Adjust. As a rule, one click with Adjust triggers a variation of the primary action that you can reach with one click on Select. The middle mouse button is called Menu, because a click of this button opens a context-sensitive menu.
• A click on a window gives it the input focus, which you can recognize by the yellow colored title bar. However, giving a window the input focus does not automatically put the window in the foreground.
• If you move a window with the Adjust button, the window will remain in its current level. If you use the Select button, the window will come to the foreground.
• Just as with windows, menus are moved by dragging the title bar.
• RISC OS uses drag & drop extensively, in particular when saving files.
• The system saves file types as metadata in the filesystem instead of as an extension of the filename.
• RISC OS uses a period to separate directories instead of the forward slash used in Linux or the backward slash used in Windows.
• RISC OS has special directories for its applications, and the name of a directory starts with an exclamation mark, or in RISC OS parlance, a pling.

For the user just beginning with RISC OS, it will take some time to get used to these differences, in particular, the way in which RISC OS handles window and filesystem operations.

Castle Technology authorized the RISC OS Open Ltd [6] to maintain the source code for RISC OS. You will find updated information on the system in the RISC OS history [7].

Look online for archives of RISC World, the former CD magazine for RISC OS. The Acorn User Magazine was published in Great Britain but no longer exists, but you can download many of its back issues in PDF format.