RISC OS 3 Q&A ------------- Overview Q: What is the purpose of this document? A: This document tries to summarise the differences between RISC OS 2.00 and RISC OS 3. It is intended to show some of the main areas of change, and explain the reasons for them, and the advantages they give. It is not meant to be a comprehensive guide for RISC OS 3. More information about the facilities provided by RISC OS 3 is provided by the RISC OS 3 PROGRAMMER'S REFERENCE MANUAL (availability will be announced at a later date). Q: What is RISC OS 3? A: Since its release in 1988 RISC OS 2.00 has been the accepted operating system for the Acorn range of ARM based computers. At the same time Acorn's software engineers have been continuously striving to improve on the facilities provided by RISC OS 2.00 and produce an even better operating system that will provide more facilities, and be easier to use by both users and software developers. RISC OS 3 is the result of these efforts. Q: Is RISC OS 3 a new operating system? A: No. While RISC OS 3 provides many more facilities than its predecessor RISC OS 2.00 it still the RISC OS operating system. Virtually all software that was written to run under RISC OS 2.00 will continue to run under RISC OS 3 without change. Q: What is Acorn's message to users? A: RISC OS 3 becomes the standard operating system for Acorn's ARM based range of computers. New and future Acorn computers starting with the A5000 will be provided with RISC OS 3 in ROM as standard. Upgrade kits will be made available for users of RISC OS 2.00 who wish to upgrade their computer to use RISC OS 3. It is Acorn's intention that RISC OS 3 will in the future be provided as standard in ROM throughout the Acorn range of ARM based computers. Q: Now that RISC OS 3 is available will Acorn stop supporting RISC OS 2.00? A: No. Support for RISC OS 2.00 users will continue for the foreseeable future. Acorn would however like to encourage as many users as possible to upgrade from RISC OS 2.00 to RISC OS 3. As more and more application software makes use of the advanced facilities provided by RISC OS 3 it is expected that more and more users will want to take advantage of these new facilities and upgrade to RISC OS 3. Q: Which computers will RISC OS 3 work on? A: RISC OS 3 release 3.00 is designed to work on the Acorn A5000 only, it is not suitable for any other Acorn computer. Acorn will make versions of RISC OS 3 available for the other Acorn computers in the new year. Q: Which computers will future versions of RISC OS 3 work on ? A: Future releases of RISC OS 3 will work on any Archimedes, A3000 or A5000 with at least 1MB of memory. Users of the Archimedes A300 and A400 range of computers (but not the A400/1 range of computers) will require some additional hardware in order to fit the new ROMs in their computer. Such hardware will be made available from Acorn through its chain of dealers. Q: Why do some computers require additional hardware? A: RISC OS 3 comes as a 2MB ROM, some older computers need extra hardware in order to be able to accept ROMs of this size. Q: Do I need a hard disc in order to use RISC OS 3? A: No. Because the operating system is resident in a 2MB ROM, you do not need a hard disc in order to get full use of it. Indeed, many of its additional facilities are primarily intended to benefit the users of unexpanded computers. RISC OS 3 makes a 1 MB, single floppy computer more powerful than ever before. Q: Will software developed for RISC OS 2.00 continue to run on RISC OS 3? A: Yes. With very few exceptions, all software which works with RISC OS 2.00 will continue to work with RISC OS 3. Q: Will all users have to upgrade to RISC OS 3? A: No. Users can continue to use RISC OS 2.00 and the applications that are available for it. Acorn hopes that the extra features of RISC OS 3 and the extra functionality that will be provided by applications written to make use of these new features will mean that most users will want to upgrade their computers. RISC OS 3 is a way of getting more out of the same computer you are using today. New functionality in RISC OS 3 Q: What are the areas of improvement in RISC OS 3? A: RISC OS 3 provides many advantages over RISC OS 2.00 these can generally be divided into two areas, additional functionality for the computer user and additional programming interfaces for software developers. The additional functionality for the user will make the computer easier to use and provide more functionality out of the same computer. It is hoped that the additional programming interfaces will be used by software developers to provide more powerful application software for use on RISC OS 3 computers. Q: What additional functionality is provided in RISC OS 3? A: The following sections provide a general overview of the additional features of RISC OS 3. The RISC OS desktop Q: What is Acorn's view of the RISC OS desktop? A: Acorn sees the desktop as the main way of using RISC OS. Acorn's aim is to continue and make the desktop easier to use. It is hoped that, in time, the need to use the command line interface to RISC OS can be eliminated completely. Following this strategy RISC OS 3 makes more of the computers functionality accessible from the desktop. All operations that are started from the desktop will now take place in a multitasking way, enabling the user to continue and do other things while the operation is taking place. Q: What improvements will a user see when using the RISC OS 3 desktop? A: Some advantages of using the RISC OS 3 desktop are: * Multitasking Filer operations. Copying, moving, and deleting files no longer takes control away from the user. The user can now go on using the computer while the filing operations are taking place. * Multitasking Format/Verify/Backup These operations, which used to take a long time on RISC OS 2.00 are now performed in the background, enabling the user to continue and make other use of the computer while they are taking place. * Multitasking Free space display. The free space display for floppy and hard discs now gives a continuous view of the free space on the disc while the computer is being used. * Additional Filer operations. It is now possible to search for a file, set a file's type, and date stamp a file from the Filer menu. * Applications in ROM. Improved versions of many of the main applications that were provided on disc with RISC OS 2.00 are now resident in ROM. These applications can be accessed using the Apps icon on the left hand side of the icon bar. * Automatic starting of applications Any of the ROM applications can be set to start automatically when the computer is powered on. * Fonts in ROM Many of the fonts that were provided on disc with RISC OS 2.00 are now resident in the RISC OS 3 ROM. * No limit on number of open windows. There is no longer a limit on the number of windows that can be opened at once. * Ability to move windows off screen. Windows can now be moved partly off screen, to increase the usable screen space. * Desktop saving Ability to save the computer's state and restore it when the user next uses the machine. * Computer shutdown. An option is provided to safely close the computer down, ready for turning it off. * Pinboard. Frequently used files can now be held on the desktop background for easy access. A background picture can also be displayed on the desktop. * Iconized windows. An open window can be shrunk to an icon, and stored on the desktop background. It can later be restored to its previous size be clicking on the icon. This helps reduce the space used by windows when they are not being actively used. * Improved printer support. A new printer driver manager !Printers is provided with RISC OS 3 which makes printing easier. RISC OS 3 makes it possible to have more than one printer connected to your computer at the same time, with all connected printers accessible from the desktop. * Ability to read MS DOS(tm) format discs. It is now possible to use disc that were created on a computer running MS DOS(tm) from RISC OS 3 to move data between the Acorn range of computers and any computer running MS DOS(tm). * Support for new A5000 high density floppy formats. It is now possible to use 1.6MB floppy discs on computers which support it such as the A5000. * Broadcast Loader. RISC OS 3 includes support for broadcast loading on Econet networks. This greatly improves the speed at which applications and data are loaded on multiple computers on the network. * ARM3 support. RISC OS 3 includes built in support for the ARM3 processor that is used on the A540,R260 and A5000 computers. * Ability to use named hard discs. Hard discs which are given a name now have their name displayed under their icon on the icon bar, eliminating the need to refer to the same disc by both its name and number. * Grouping of icon bar icons. On RISC OS 3 icons of the same type will appear on the icon bar in a group, regardless of the order they were added to the icon bar. For instance all hard disc icons will appear in a group, and so will all the fileserver icons. This makes finding the icon you want easier. * Enhanced interactive help. When running !Help, help can now be provided on menu items as well as on icons and windows, making it easier to learn how to use new application software. * Extension modules in ROM. All of the standard extension modules for RISC OS 2.00 such as ColourTrans, the floating point emulator, the outline font manager and the shared C library are now in the RISC OS 3 ROM leaving more memory for application software. * Up to 128 tasks. RISC OS 3 can support up to 128 tasks running together in the computer as opposed to the 32 allowed by RISC OS 2.00. * New hot keys. New hot keys are provided to open a task window, move the icon bar to the front, and start a shutdown. * Screen blanker. A screen blanker is included in the RISC OS 3 ROM to help preserve the monitor screen. ROM Applications. Q: Which applications are provided in the RISC OS 3 ROM? A: The following applications are provided in ROM: * !Alarm - A clock and calendar application. * !Calc - A simple 4 function calculator. * !Chars - An application enabling access to characters not available from the keyboard * !Configure - An application enabling configuration of the computers startup state. * !Draw - A drawing application. * !Edit - A text editor. * !Help - A way of getting help on how to use the desktop and other applications. * !Paint - A simple painting application and sprite editor. Q: What are the advantages of having applications in ROM? A: Having an application in ROM makes accessing it very easy. There is no need to store it on disc, or to find the disc it was stored on when you want to access it. Q: Does having these applications in ROM leave more memory free for other applications? A: Using RISC OS 3, any of the ROM resident applications are run directly from ROM. Running the application from ROM means there is more memory left for other applications to run in at the same time. For example, !Edit used to need at least 160K to run, it now only needs 64K. Q: What changes have been made to !Alarm? A: !Alarm has been improved in a number of ways: * Much improved support for setting and resetting of alarms. * A list of alarms can be obtained in textual format. * Repeating alarms can be made to fit in the working week. * Better control over repeating alarms. For example, an alarm can be made to repeat on the first Sunday of every second month. * Support for automatically changing between summer and winter time. * An alarm can be set up to start a task. Q: What changes have been made to !Calc? A: It is now possible to use the computer's keyboard to enter numbers and perform calculations using !Calc. Q: What is !Chars? A: !Chars is a utility that gives access to characters that the computer can use but are not normally available from the computer's keyboard. Characters are typed by clicking on them using the mouse. Q: What changes have been made to !Configure? A: !Configure has been redesigned to give the user better control over the computer's configuration, and to support new configuration options. !Configure now provides several windows that provide control over the following areas of the computer's configuration: * Discs - Provides control over the number of hard discs connected to the computer. This includes support for SCSI based hard discs, and the new IDE disc interface as used in the A5000. * Floppies - Provides control over the number of floppy disc drives connected to the computer. * Net - Provides control over settings related to the use of the Econet(tm) network including the use of the new broadcast loader facility. * Printer - Provides control over the port to be used for printing. * Mouse - With RISC OS 3 many aspects of the mouse sensitivity can now be controlled by the user. This window can be used to change elements of the mouse sensitivity such as the mouse speed. * Keyboard - Provides controls over different aspects of the keyboard such as the keyboard auto repeat rate. * Memory - Provides control default memory allocations to system areas. * Sound - Provides control over the computer's sound system, such as the volume of sound produced. * Screen - Provides control over the screen display options such as the default screen mode. * Fonts - Provides control over the thresholds used by the font manager. * Windows - Provides control over Window Manager options such as the ability to move windows off screen. * Applications - Provides control over which of the ROM based applications are started automatically when the computer is powered on. Q: What changes have been made to !Draw? A: !Draw has been greatly enhanced and now provides amongst other things, the following new functionality: * Keystroke equivalents. Many of the common operations now have keystroke equivalents. * Interpolation of colours. It is now possible to produce smooth colour grading between two paths. * Scrolling at window boundary. If the pointer enters the outer 5% of the window, and you have a mouse button other than menu held down, the window will scroll and the mouse pointer is kept within the inner 95%. * Undo function Operations can now be undone. A history is kept so that operations preceding the last one can also be undone. * Text to path conversion Text lines rendered in an anti-aliased font may be converted into a group of path objects. * It is now possible to change the contents of text lines. * Support for rotated fonts. * Support for rotated sprites. Q: What changes have been made to !Edit? A: !Edit has been changed to provide amongst other things the following new functionality: * Column tab, overwrite and wordwrap modes added. * Support for wildcarded expressions as well as the old style magic characters for find operations. * Now works with an unlimited number of fonts. * Support for editing BASIC programs. Q: What changes have been made to !Help? A: The help system has been expanded to provide interactive help on menu entries as well as on windows and icons. All of the applications provided with RISC OS 3 provide interactive help. Q: Will RISC OS 2.00 applications work with the help system on RISC OS 3? A: Yes, the interactive help system has been present in RISC OS 2.00 since its release in 1988. Many applications already provide support for interactive help. Applications written for RISC OS 2.00 will not however provide help on menu entries. Q: What changes have been made to !Paint? A: Paint has been changed to provide amongst other things the following new functionality: * Replace colour will now replace transparent with a colour, and a colour with transparent. * New operations Scale x, Scale y and Shear. * Get Screen Area replaced with a timed snapshot facility. * Ability to use shapes such as circle, triangle, and square as a brush. Outline fonts in ROM Q: Is the outline Font Manager now provided as standard? A: Yes. RISC OS 3 includes the latest version of the outline Font Manager in ROM. Q: What are the advantages of having outline fonts? A: Outline fonts give better results when scaled to different sizes. Q: Is the outline font technology new? A: No. Outline font technology is not new for RISC OS. An outline font manager has been available for RISC OS 2.00 for some time now. As a result, many outline fonts are already available for use with RISC OS 3. Q: Is the outline Font Manager provided with RISC OS 3 the same as the one provided with Acorn DTP for RISC OS 2.00? A: No. While it is similar, and uses the same outline font technology as the RISC OS 2.00 outline Font Manager, the RISC OS 3 Font Manager version is a much improved version of the one provided for RISC OS 2.00. Q: Will documents created on RISC OS 2.00 still work with the RISC OS 3 font manager? A: Yes. The RISC OS 3 Font Manager is compatible with earlier versions. Q: Can fonts that are used with the RISC OS 2.00 Font Manager still be used with the new version? A: Yes. While not all fonts provided for the RISC OS 3 Font Manager can be used with the RISC OS 2.00 version, all fonts used by the RISC OS 2.00 Font Manager can be used with the new RISC OS 3 version. Q: What advantages does the RISC OS 3 Font Manager have over the RISC OS 2.00 version? A: The RISC OS 3 Font Manager offers many advantages over the RISC OS 2.00 version, some of which are: * The ability to paint rotated and transformed fonts. * The ability to cache single characters. * Support for right-to-left scripts. * Support for multiple font directories. * Support for different character set encodings. Q: What are the advantages of having fonts in ROM? A: Having fonts in ROM means less memory is used by the Font Manager when using these fonts, leaving more memory free for applications. Q: Which fonts are provided in the RISC OS 3 ROM? A: The fonts provided in ROM are: * Corpus.Medium * Corpus.Medium.Oblique * Corpus.Bold * Corpus.Bold.Oblique * Homerton.Medium * Homerton.Medium.Oblique * Homerton.Bold * Homerton.Bold.Oblique * Trinity.Bold * Trinity.Bold.Italic * Trinity.Medium * Trinity.Medium.Italic Desktop saving Q: What is desktop saving? A: Desktop saving is a way of saving the computer's state so that it can be restored the next time it is used. Q: How is desktop saving done? A: A new entry has been added to the Task Manager menu that allows the user to create a desktop boot file. Running the file after it has been saved, or installing it as the computer's boot file will restore the computer to the state it was when the file was saved. Q: What exactly is this computer state? A: The computer state includes: * Running applications. * Open directory viewers. * Any logged on fileservers. * Any icons on the desktop background. * The backdrop picture. It does not include: * Any open application windows. * Any iconized windows on the desktop background. Q: Will running RISC OS 2.00 applications be restored by a desktop boot file? A: No. Applications need to know about this facility in order to support it. All the applications provided with RISC OS 3 (both in ROM and on disc) already support this facility. All future applications should support this facility. Computer shutdown Q: What is computer shutdown? A: An option has been added to the Task Manager's menu that will bring the computer to a state where it can be safely turned off. The user is warned about any unsaved data in the computer, and then logged off from any fileservers, and all hard discs are parked. Q: Why is this option needed? A: This option simply ensures that no data will be unintentionally lost when switching the computer off. Parking the hard discs is also safer for transporting the computer from place to place. Pinboard Q: What is Pinboard? A: Pinboard in an extension to the desktop that enables frequently used files, directories and applications to be stored on the desktop background. Q: How are files stored on the desktop background? A: Simply dragging a file to desktop background will put the file icon on the background. The file can then be used in the same manner as it would be used from a Filer window. Iconized windows Q: What are iconized windows? A: Iconized windows are a small representation for an open window that can be stored on the desktop background. Q: Why are iconized windows useful? A: Iconizing a window preserves the context represented by the window, but frees up the space it uses until it is needed again. Q: Is it possible to iconize windows belonging to applications written for RISC OS 2.00? A: Yes. Iconizing will work on any window in the system. Applications written for RISC OS 3 have better control over the shape and name given to the iconized window, but iconizing will work on any window. Q: Is an iconized window still active? A: Yes. An iconized window remains active. For example, a warning will be generated if there is any unsaved data in an iconized window and the shutdown option is selected. Improved printer support Q: In what ways is the printer support better under RISC OS 3? A: Printer support has been greatly enhanced to include: * Full print queue facilities. * The ability to have more than one printer active at a time. * Much easier configuration for new printer types. * Support for all the new RISC OS 3 facilities such as printing of documents containing transformed sprites and fonts. * Support for font downloading. Q: What do the queue facilities provide? A: The queue facilities provide the ability to print multiple files by simply dragging them to the printer icon. The files are queued and printed one after the other. It is possible to suspend and remove individual entries from the queue and. An indication is also given of how far through the file the printing has progressed. Q: Why is the support for more than one active printer important? A: RISC OS 2.00 only supported one active printer at a time, this meant that people with more than one printer had to constantly switch between different printer drivers. Using the RISC OS 3 Printer Manager they can now have both printers active and simply drag the file to the correct icon for it to be printed. Q: Why is easy printer configuration important? A: While Acorn provides configuration files for a large range of printers, we cannot possibly provide a configuration file for every printer in the market. Easily configureable printer types enable the user to configure the Printer Manager to work with their printer without having to rely on the printer manufacturer or Acorn to provide a configuration file for them. Q: What is font downloading? A: Font downloading allows users with PostScript(tm) printers to print their documents which contain Acorn outline fonts on their printers without the need to purchase the appropriate PostScript(tm) font for their printer. Q: Is font downloading available with the standard RISC OS 3? A: No. While support for font downloading is included in RISC OS 3 the font downloading facility will be made available shortly as an extension to the basic RISC OS 3 functionality. Q: Will printer drivers from RISC OS 2.00 continue to work on RISC OS 3? A: Yes. Some independent vendors have developed printer drivers for printers that may not be supported in the extended Acorn set, these printer drivers will continue to work unaltered. Ability to use MS DOS(tm) discs Q: What is MS DOS(tm)? A: MS DOS is the standard operating system used by IBM PCs(tm) and compatible computers. It is also the disc format used by the Acorn PC emulator. Q: How is the support for MS DOS(tm) discs integrated into the RISC OS 3? A: When using RISC OS 3, MS DOS(tm) format discs can be used just like the native RISC OS ADFS and SCSI formats. Directory viewers can be opened on MS DOS(tm) discs and they can be read from, written to, and even formatted. Q: What happens to MS DOS(tm) file names under RISC OS 3? A: A translation mechanism is used to map MS DOS(tm) file names onto RISC OS names. RISC OS 3 also gives the user the option of truncating the names to 10 characters, or leave them as they are. Q: Is it possible to run MS DOS(tm) applications on a RISC OS 3 computer? A: Yes. It has always been possible to run MS DOS applications under RISC OS by using the Acorn PC emulator. Q: Can PC emulator hard disc partitions be manipulated from outside the PC emulator? A: Yes. It is now possible to open a directory viewer on the PC emulator hard disc partition and use it as if it were a normal directory on the hard disc. Q: Is it possible to use high density PC discs under RISC OS 3? A: Yes. On computers equipped with the appropriate hardware such as the A5000 it is possible to use high density PC disc formats. Support for new A5000 high density format. Q: What is the new high density format? A: On the A5000 it is possible to use high density floppy discs to give up to 1.6M formatted capacity on an ADFS format disc. Support for this format has been integrated into RISC OS 3. Programming interface changes. Q: Are there any new programming interfaces provided by RISC OS 3? A: Yes. While a lot of effort went into improving the system for the user, no less effort went into providing additional programming interfaces and improving the existing ones. Q: Why does so much effort go into improving the programming interface? A: Acorn hopes that the new programming interfaces will enable software developers to develop far more powerful applications for RISC OS 3 than the ones possible under RISC OS 2.00. Improving the programming interface is an investment in the future. While it is of no immediate importance to the user of the computer it increases the potential power of the computer and the applications that will be developed for it. Q: How could the programming interface be changed without harming compatibility with RISC OS 2.00? A: Whenever possible, if a new interface was added to RISC OS 3. the old interface available in RISC OS 2.00 was kept as well. While Acorn does not recommend that new application software written for RISC OS 3 uses these old interfaces, they continue to work. However in most cases the old interfaces are less powerful and so applications using the old interfaces will provide the maximum functionality possible using the new RISC OS 3 interfaces. Q: What will happen to these old interfaces in the future? A: Support for the old interfaces will continue for the foreseeable future. However, in time, as more and more applications become available for RISC OS 3, it is Acorn's intention to stop supporting these old interfaces. Main themes behind the changes Q: What motivated the changes? A: As well as the desire to provide better support for application development there are two main themes behind the changes to the programming interface in RISC OS 3 internationalisation and support for foreign filing systems. Q: What is internationalisation? A: Internationalisation has three main aspects. The first is to enable Acorn to produce a version of RISC OS 3 targeted at a foreign market. This requires not only the ability to translate all system text to a foreign language but also the ability to support different time zones, different alphabets and different keyboard layouts. The second aspect of internationalisation is to enable application software to be written in a way that enables easy adaptation of the software for a foreign market. The third aspect is to enable application software to be written that can cope with using more than one language at the same time. RISC OS 3 attempts to address all of these aspects. Q: What is the support of foreign filing systems? A: The support of foreign filing systems is the ability to read and write disc formats that are used by other computers. An example of this ability is the RISC OS 3 ability to read and write MS DOS(tm) format discs. Many of the changes to the programming interfaces at the filing system level were motivated by the desire to support this type of data exchange. Overview of the changes Q: What areas were changed? A: Changes occurred in all areas of the system but most noticeably in the following areas: * The kernel * Device drivers. * Time zones. * Extension ROMs. * Unique ID. * The Podule Manager * The way modules are loaded off extension cards. * Filing system interfaces * Support for foreign filing systems. * ResourceFS * A new resource filing system. * The Messages module * A central text resource for RISC OS 3. * MessageTrans * A new central message translation facility. * TerritoryManager and UK Territory. * The general internationalisation support and UK specific resources. * The Task Manager * Support for enumeration of tasks. * ARM3Support * Support for the ARM3 processor. * Buffer Manager * General buffer management support. * Font Manager * Support transformed fonts. * Support for internationalisation. * Support for dynamic font menus. * PipeFS * Support for piped data transfer. * SpriteExtend * New sprite operations for plotting transformed sprites. * Squash * Support for data compression. * TaskWindow * Much improved support for running non-desktop tasks under the desktop. * WindowManager * Support for redefined window borders. * Many additional interfaces. * FilterManager * Ability to provide filters on wimp tasks. * In addition to the above list the latest versions of the following modules are included in the RISC OS 3 ROM: ColourTrans FPEmulator SharedCLibrary IRQUtils WindowUtils Device Drivers Q: What are the changes to the device driver interface? A: RISC OS 3 provides a device filing system (DeviceFS). This new module provides filing system like interfaces to device drivers and devices. It defines the way in which device drivers should be written for RISC OS 3 and provides a uniform interface to them. Q: Which devices use DeviceFS? A: Currently the serial and parallel device drivers have been extracted from the kernel and changed to use the DeviceFS interface. This will make it easier to adopt them to work on possible future hardware. Time zones Q: What changes were made to the way RISC OS handles time? A: RISC OS 2.00 did not have any concept of time zones. This caused difficulties when interfacing to other computers. RISC OS 3 now has knowledge of time zones and time offsets. Time under RISC OS 3 is always kept in UTC (Universal Time Coordinated). Interfaces are provided to translate between UTC and local time, and back. Extension ROMs Q: What are extension ROMs? A: Extension ROMs are additional ROMs other than the main system ROM. These ROMs can be fitted into computers that include the necessary hardware such as the A5000. RISC OS 3 will support such ROMs on any Acorn computer that has hardware supports for them. Q: Why are extension ROMs necessary? A: Extension ROMs can be used to provide support for specific hardware which may be present in a limited set of computers. The extension ROM mechanism allows support for such hardware to be included without the need to re-issue the main system ROMs. Unique ID Q: What is the unique ID? A: Some Acorn computers such as the Acorn A5000 have a unique machine ID assigned to them when they are manufactured. This is a number that is unique to the individual machine, and is not duplicated on any other Acorn computer. Q: What will the unique machine ID be used for? A: It is anticipated that software developers will use the unique machine ID for software protection. The Podule Manager Q: Why was a change to the Podule Manager necessary? A: On RISC OS 2.00 any module present on the podule was automatically loaded into the computer without first checking if a later version of the module was already resident in the computer. This was not a serious problem with RISC OS 2.00 as the podule normally had a later version of the module than the one present in the RISC OS 2.00 ROM. With RISC OS 3 many modules have been updated and included in the ROM with the result that in most cases the module in the RISC OS 3 ROM will be a later version than the module on the podule. Using the old method of loading modules would have meant that the newer module would have been overwritten by the older one. Q: What has been done? A: With the RISC OS 3 Podule Manager, modules are only loaded from a podule if there isn't already a later version of the module resident in the computer's memory. If there is a later version of the module in the computer's memory (in the system ROM, an extension ROM or in RAM) it will be restarted with the necessary arguments, instead. Filing system interfaces: Q: What are the changes to the filing system interface? A: The detailed changes to the filing systems are beyond the scope of this document (for details refer to the RISC OS 3 PROGRAMMER'S REFERENCE MANUAL). In summary the filing system interface has been changed in two major ways: it has been enhanced to support the implementation of foreign filing systems, and to make the writing of native filing systems much easier. ResourceFS Q: What is ResourceFS? A: ResourceFS is a filing system that enables applications and modules to hold resources (such as messages files, template files and sprite files) in the computer's memory, and access them using the filing system interface. All of the RISC OS system modules use ResourceFS to hold their resources. Q: Can ResourceFS be used by applications and modules which are not in the RISC OS 3 ROM? A: Yes. ResourceFS provides an interface that can be used by any application software. For example, ResourceFS makes the inclusion of sprites for Filers that reside on podules much simpler, eliminating the need for a filing system to be implemented on the podule. The Messages module Q: What is the messages module? A: The messages module is the central text resource for the system most of the text used by RISC OS 3 is held in this module so that it easily be replaced by loading a replacement module. MessageTrans Q: What is the MessageTrans module? A: The MessageTrans module is a module providing message translation facilities by using message tokens and messages files. Q: Is the RISC OS 3 MessageTrans module the same as the one provided with the Acorn release 2 printer drivers? A: No. While the new RISC OS 3 MessageTrans provides all the functionality of the old module it is an updated version which provides facilities for the translation of error messages and support for the use of a shared global messages file. The Territory Manager and UK Territory Q: What is the Territory Manager? A: The Territory Manager is a new RISC OS 3 module providing control over the localized aspects of the computer. The Territory Manager can have more than one Territory module loaded at any one time but only one can be the active Territory for the computer. Q: What is a Territory module? A: A Territory module (such as the UK Territory module present in the RISC OS 3 ROM) is a module providing the Territory Manager with information about a specific Territory (such as the UK). This information includes things like the time zone, the language used, the keyboard layout used, which character to use for the decimal separator, the collation order for characters, the writing direction for the local language, and more. Q: What is the current Territory? A: Each computer running RISC OS 3 has a value for the current Territory stored in its CMOS RAM. This value controls the Territory that is used by the system. This is the current Territory of the computer. The current Territory controls such things as the language used to display menus, and the default time offset from UTC. There can only be one current Territory for any one computer. Q: Why is there only one current Territory? A: Since the current Territory controls such things as the language used for menus. It would be very confusing to have, for example, some of the menus appear in one language and some in another language. In the UK, even if you are editing a German document you would normally want the menus to still appear in English. Q: If there is only one current Territory, why should it be possible to have more than one Territory loaded by the Territory Manager? A: While there can only be one current Territory for any one computer, some applications written for RISC OS 3 may wish to be able to include text in two different languages in the same document. It is useful for such an application to be able to read the information relating to both languages at the same time. The Task Manager Q: What are the changes to the Task Manager? A: Using RISC OS 2.00 it wasn't possible for an application to obtain a list of the tasks that were active in the computer's memory. Using RISC OS 3 it is now possible to enumerate all the resident tasks. The ARM3 Support module Q: What does the ARM3Support module provide? A: The ARM3Support module that is included as standard in the RISC OS 3 ROM gives application software control over various aspects of the ARM3 processor that is installed in the A540 and A5000. Calls are provided to enable and disable the ARM3 cache, and to mark areas of memory as cacheable and non cacheable. The Buffer Manager Q: What is the Buffer Manager? A: The Buffer Manager is a new module provided in the RISC OS 3 ROM that provides general purpose buffer management. Application software can now use the facilities provided by the Buffer Manager instead of implementing their own buffering mechanisms. The Font Manager Q: What are the changes to the Font Manager? A: The detailed changes to the Font Manager are beyond the scope of this document. Changes have been made in three major areas: support for transformed fonts, internationalisation, and multiple font directories have been added. Q: What are dynamic font menus? A: Dynamic font menus are font menus that change when you add a new font to the list of fonts without the need to restart the application. The RISC OS 3 Font Manager provides support for such menus, and all the applications provided with RISC OS 3 use this facility to provide such menus. Q: Will RISC OS 2.00 applications work with this new facility? A: No. An application needs to know about the facility to use it. All new applications written for RISC OS 3 should have this facility in them. PipeFS - The Pipe filing system Q: What is PipeFS? A: PipeFS is a RISC OS 3 filing system that provides a facility similar to pipes under UNIX(tm). Q: What are pipes? A: Pipes are a way of transferring data between two different tasks, without the need for an intermediate file to be created on disc. Q: What does PipeFS do? A: PipeFS enables intermediate files to be created in memory for the purpose of data transfer. Such files are deleted automatically when they are closed. Q: What is special about a pipe file? A: When data is read from a normal file it stays in the file, when data is read from a pipe the data is removed from the file. So that one task can write to the file at one end, and another task can remove the data from the other end at it's own pace. New Sprite operations Q: What are the new sprite operations in RISC OS 3. A: RISC OS 3 provides a number of new sprite operations: * Insertion and removal of multiple rows and columns. * Plotting of transformed sprites. * Plotting of a sprite into a destination parallelogram * Plotting of part of a sprite. Q: Which applications support the new operations? A: Only applications written for RISC OS 3 will support these operations. Support for them is included in the version of !Draw provided in the RISC OS 3 ROM. The Squash module Q: What is the Squash module? A: The Squash module is a new RISC OS 3 module providing a general purpose interface to data compression. Q: What is the compression ratio achieved by the module? A: The compression algorithm used by the module achieves an average of %40 compression on text and sprite files. Q: What is the compression speed achieved by the module? A: The module provides a fast and a slow algorithm. The slow algorithm achieves a compression rate of about 24K per second and decompression rate of about 48K per second while the fast algorithm achieves a compression rate of about 68K per second and a decompression rate of about 280K per second on a standard A420 computer. The task window module Q: What are the changes in the task window module? A: An improved version of the task window module is present in the RISC OS 3 ROM. This new version includes support for starting of tasks from within other tasks, and for running tasks under the control of the task window module without actually opening the window on the screen unless output is generated by the task. Q: Has access to the task window been made easier? A: Yes. A task window will now be opened if the user presses Ctrl+F12 at any time. The Window Manager Q: What are the changes to the Window Manager? A: Some of the changes made to the Window Manager are: * Limit on number of windows removed. * Limit on number of tasks increased to 128 (from 32 on RISC OS 2.00) * *WimpMode command added to set the current wimp mode. * Support for customised sprites for different aspect ratios added. * Many more sprites are now provided in ROM. * The RISC OS 3 Window Manager supports computers with more than 4MB of memory such as the A540 * The following routines now work on the icon bar as well as on normal windows: Wimp_GetWindowState Wimp_GetWindowInfo Wimp_GetWindowOutline Wimp_ForceRedraw Wimp_DragBox Wimp_WhichIcon * A Message is now issued when a menu is deleted. * Support for menus that are traversed from right to left * Support for iconizing windows added. * Many additional validation string options added. * Ability to use poll words added. A task can now request to get an event when a poll word becomes non zero. For a more complete description of these and other changes and additions refer to the RISC OS 3 PROGRAMMERS REFERENCE MANUAL. The Filter Manager Q: What is the Filter Manager? A: The Filter Manager is a new RISC OS 3 module that enables specially written software to intercept events that a task receives from Wimp_Poll act on them and filter them. The filter is also able to generate new event types that are then reported to the task through the Wimp_Poll mechanism. ----- RMokady@acorn.co.uk | Ran Mokady | "We're children, Needing other children Senior Software Engineer | And yet letting our grown up pride RISC OS development team | Hide all the need inside Acorn Computers | Acting more like children than children" Cambridge, UK. |