RISC OS Programmers Reference Manuals : New OS modules

Introduction

This chapter lists the modules supplied as part of the operating system, a short summary of each one's function, and where its documentation can be found.

Since RISC OS 3.6 was released, many new features have been added to RISC OS. These features are not documented within PRM 5a, which only documents up to RISC OS 3.6.

Modularised Kernel components

Many components have been moved out of the Kernel into separate modules. This allows them to be replaced should faults be located, or augmented if their behaviour needs to be changed. From an internal development standpoint, this separation increases the maintainability of both the separated component and the Kernel itself by isolating functionality. Many of these modules provide APIs which are unchanged from their original forms. Refer to the PRMs for details of the implementations.

Module	Function and documentation
Conversions	OS_Convert* SWI calls. No specific documentation; see PRM 1.
OSSWIs	Miscellaneous SWI calls. No specific documentation; see PRM 1.
EvaluateExpression	OS_EvaluateExpression SWI. See PRM 1-457, section EvaluateExpression.
SystemVars	Management of Sys$* variables. Version 0.08 and above handle all system variables. No specific documentation; see PRM 1.
ReadLine	Line input 'ReadLine vector'. See section ReadLine.
CLIV	*-command interpreter. No specific documentation; see PRM 1-929.
VideoTTX	Software implementation of Teletext mode. See section Teletext.
VideoSW	Software implementation of most text and graphics primitives. See section Graphics.MultiDrivers.
VideoHWVIDC	Hardware implementation of the video system for VIDC. See section Graphics.MultiDrivers.
FSCommands	Filing system *-commands previously located in the Kernel. No specific documentation; see PRM 1.
ModuleCommands	Module manipulation *-commands. No specific documentation; see PRM 1.
OSCommands	*-commands which do not fall into the FSCommands or ModuleCommands groups. No specific documentation; see PRM 1.
RTC	High level Real Time Clock functions. See PRM 1-399, section RTC, RTCV, OS_Word15.
RTCHW	Hardware access for the Real Time clock, for RiscPC, A7000, RiscStation and A9 systems. See section RTCV.
OSPointer	High level pointer functions. See PRM 5a-242, section PointerDevices, PS2Driver, WindowScroll.
PrinterBuffer	Configuration of the printer buffer. No specific documentation.
NVRAMHW	Hardware access to the non-volatile configuration memory. See PRM 1-363, section NVRAMV.
IRQ	Interrupt dispatch management. See PRM 1-121, section IRQHandler.
Timer	Hardware timer management. See section Timer.

Graphics components

The increased support for non-native graphics formats and the extended functions provided by the existing systems have required a number of new modules. Many of these are described in more detail in the GraphicsSystem section and the Graphics.MultiDrivers section.

Module	Function and documentation
ColourMap	Colour translation and remapping. See sections ColourMap, ColourMap-DrawFile, Graphics.Sprites.ColourMap.
BlendTable	Support for transparent blending. See section BlendTable.
FontMap	Non-native font name translation. See section FontMap.
PNG	Library for decoding and encoding of PNG bitmap images. See section PNG.
ImageFileConvert	Generic image file conversion interface, providing ImageFileRender for converted files. See section ImageFileConvert.
ImageFileRender	Generic image rendering. See section ImageFileRender.
CompressJPEG	JPEG compression, decompression and transcoding functions, now part of the ROM rather than being disc based. See PRM 5a-609, section CompressJPEG.
ConvertPNG	PNG file conversion using ImageFileConvert. See section ConvertPNG, ImageFileConvert.
ConvertBMP	BMP file conversion using ImageFileConvert. See section ConvertBMP, ImageFileConvert.
ConvertICO	Windows .ico file conversion using ImageFileConvert. No specific documentation; see section ImageFileConvert.
ConvertPNM	PNM (PBM, PPM, PGM) file conversion using ImageFileConvert. No specific documentation; see section ImageFileConvert.
ConvertSprite	Sprite file conversion via ImageFileRender, using ImageFileConvert. See section ConvertSprite, ImageFileConvert.
ConvertSun	Sun raster file conversion using ImageFileConvert. No specific documentation; see section ImageFileConvert.
ConvertXBM	X bitmap file conversion using ImageFileConvert. No specific documentation; see section ImageFileConvert.
ConvertPCX	PCX file conversion using ImageFileConvert. No specific documentation; see section ImageFileConvert.
ConvertClear	Translator 'Clear' file conversion using ImageFileConvert. No specific documentation; see section ImageFileConvert.
ImageFileRender_Artworks	Artworks file rendering using ImageFileRender. No specific documentation; see ImageFileRender.

Desktop components

The Desktop has been enhanced both visibly, through the new Icon Bordering interface, and behind the scenes by providing enhanced interfaces for various components.

Module	Function and documentation
RedrawManager	Managed, filter based redraw functions, allowing non-application components (for example Toolbox) to perform rendering within application windows. See section RedrawManager.
IconBorderPlain	Re-implementation of basic button style. No specific documentation.
IconBorderRound	Updated button style, allowing round buttons and other effects. A general IconBorder development kit and documentation are available on request.
ClipboardHolder	Clipboard support functions to aid application developers and used by the WindowManager to provide cut-and-paste within writable icons. See section ClipboardHolder.
WindowScroll	Support for scrolling windows using the alternate pointing device (for example, a scroll wheel). See section WindowScroll.

Toolbox components

Although the Toolbox as a whole has been enhanced, only a few new modules are provided within the current version of the operating system.

Module	Function and documentation
GDivider	A semantic 'divider' gadget. No specific documentation; see toolbox headers.
ToolAction	Advanced version of the regular 'Action' buttons. No specific documentation; see toolbox headers.
TextGadgets	Text-based gadgets - scrolling lists and text input area. No specific documentation; see toolbox headers.
ImageFileGadget	Gadget for rendering ImageFiles within a window. No specific documentation; see toolbox headers.

Programmers components

Module	Function and documentation
ZLib	Library for compressing using the ZLib compression method. See section ZLib.
Zipper	Library for reading and creating Zip archives. See section Zipper.
DiagnosticDump	Diagnostic functions for Shared C library and other external implementations. See section DiagDump.
KeyInput	Extended keyboard input interfaces. See section KeyVExtendedInput.
BASIC64	Floating point version of the BASIC library, now part of the ROM, rather than being disc based. No specific documentation.
DDEUtils	Advanced developer functions such as longer command lines and editor throwback. No specific documentation.
PathUtils	System 'path' variable manipulation functions. No specific documentation.
SysLog	Centralised logging. No specific documentation.

Network components

The network components have been enhanced considerably since their initial release with RISC OS 3.6. The network chapters contain more details of the specific functions of the new modules and of the enhancements to the existing modules.

Module	Function and documentation
InetServices	Translation between service names and numbers. No specific documentation.
Resolver	Translation between host names and addresses. See section Resolver.
MimeMap	Translation between MIME media types, filetypes, file extensions and Mac data types. See section MimeMap.
InetConfigure	Management for automatic network configuration on startup. See section AutomaticConfiguration.
DHCPClient	Automatic network configuration using the DHCP protocol. See section DHCPClient.
ZeroConf	Automatic network configuration using the Link-local addressing protocol. See section ZeroConf.
RouterDiscovery	Automatic gateway discovery using the ICMP router discovery protocol. See section RouterDiscovery.
FreewayHosts	Distribution of host names over Freeway, previously an internal function of the Freeway module. See section Networking.Overview.
LanManFS	Access to Windows (and other) filing systems. No specific documentation.
AppleTalk	Access to Apple filing systems. No specific documentation.

Legacy support components

As the operating system has developed, a number of functions have become obsolete, or have required different handling. These functions have been moved to separate components so that they can easily be removed, and to make maintenance of the core components simpler.

Module	Function and documentation
LegacyBBC	Many of the obsolescent BBC interfaces are provided through this module. See section LegacyBBC.
LegacyScreen	With the advent of multiple display devices within a system, the single 'Screen' dynamic area no longer has any purpose. This module provides this dynamic area so that components which require the area still function. See section LegacyScreen.
CallASWI	As support for StrongARM (split cache) and 32bit systems, the CallASWI module was introduced. Its functionality is now part of the core operating system. This module merely prevents unsuitable versions of the module from being used. No specific documentation.

Miscellaneous components

Finally, a few components do not fit easily into any of the above categories and are listed here.

Module	Function and documentation
OwnerBanner	Provides the new start up banners for both the Desktop and boot. No specific documentation.
LibraryHelp	Extends the *Help system to provide additional information for library commands and aliases. See section LibraryHelp.
FileTypes	A stub module which sets up many of the common filetypes and their execution formats on startup. Previously this was part of FileSwitch. No specific documentation.
AIF	In order to ensure the stability of the system, and to allow support for emulated execution of non-32bit safe programs, Absolute files are now checked and executed by the AIF module. Previously this task was a part of FileSwitch. See section Exec Formats.
TransientUtility	Provides support for transient utilities, similar to that for AIF-headered absolute files, primarily to enforce the new headered utility file format. See section Exec Formats.
ScrSaver	Provides management of desktop screen savers. No specific documentation.
SharedSound	Support for multiple clients of the 16bit sound system. No specific documentation.

New OS modules