~04/1995
Getting the best from the Outline Font Manager The Outline Font Manager is provided as standard with RISC OS 3, and can be used with RISC OS 2 although it is not a part of built in OS ROM. There are a number of configuration settings available which allow you to tune the performance of the Outline Font Manager to best suit the way that you use your system. It is important to ensure that there is an adequate amount of space allocated for the font cache. This is an area of memory which is used to hold font data within the computer's memory rather than having to go and fetch it from disc each time it is needed. The initial size of the area after a reset/power on can be set with *configure FontSizeK (or using !Configure). Even if you only make minimal use of fonts you should always ensure that there is some font cache available. The optimum setting to use depends upon the amount that you use fonts. A useful yardstick is to put aside around 64K-128K per megabyte of memory in the computer, so on a 2MB machine the setting would be between 128K and 256K. The maximum setting is 1024K. Intensive font users may wish to use 256K per megabyte instead. However setting the size of the font cache is not the end of the story. The next decision to make is where to place the tradeoff between high quality anti-aliased characters and memory consumption/performance. Anti-aliasing consists of determining how much of a character outline occupies a given pixel. This information is used to choose a colour between the foreground and background colour to represent it (this is typically a range of greys between black in the foreground and white in the background). The result of this is that characters will look much less jagged and more pleasing to the eye. However calculating anti-aliasing takes time, so there is a tradeoff to be made. You can also decide at which size of character anti-aliasing should not be used since the character has become large enough not to require anti-aliased pixels to assist its definition. These settings are controlled by the five fontmax configuration values. RISC OS 3 users may alter them by using !Configure. Any RISC OS user can change them by pressing F12 and typing 'configure fontmax '. is the fontmax number (1-5) and is the point size. Fontmax2 and Fontmax3 (described as 'Use anti-aliasing for characters' and 'Use cached bitmaps for characters' in !Configure) jointly set the maximum point size of character which will be drawn using anti-aliasing. If the point size used is larger, it will be scaled directly from the outlines without being anti-aliased. Set both of these to the maximum point size that you want anti-aliasing to be used with. Note: The above is a great simplification of the real situation - those interested in reading further should consult the RISC OS 3 Programmer's Reference Manual. Acorn Pocket Book A-Link The Acorn Pocket Book A-Link allows you to transfer data between a Pocket Book and an Acorn 32 bit computer, and consists of a hardware link and a software application which runs on the 32 bit workstation. The A-link has advanced features which make it easy to use and because of this RISC OS 3 (Version 3.10 or later) is required. This is provided as standard with all new A3000 (ie A3010 and A3020), A4000, A5000 and A4 computers, and is available as a low-cost upgrade to existing Archimedes owners. For further details contact your local supplier.