ColourShift  -  Quick screen mode changer

by Alan Wrigley

Back in RISC User 8:4 we published an application called Modus Operandi which enables Risc PC users to define screen mode numbers for their favourite modes and then to access those modes by using Shift-Alt plus the keypad. While this is fine if you use a number of different modes regularly and want a faster way of changing than by using the Display Manager, in fact most mode changes are necessitated by the need to alter only the number of colours, not the resolution.

ColourShift addresses this need by allowing you to increase or decrease the colour depth on the desktop by using the Alt key in conjunction with the plus and minus keys on the keypad. If when changing up, your machine does not have enough VRAM to support the increased colours, the screen resolution will drop to a value that does allow it. Similarly, when changing down, if a greater resolution is possible then this will be increased, up to the maximum resolution specified in your configuration settings. For example, on my machine I work normally on a 1024x768 desktop with 32,000 colours. If I change up to 16 million colours, this can't be supported at 1024x768, so ColourShift drops the resolution to 800x600, which is exactly what the Display Manager does in the same circumstances. When I then change back to 32,000 colours, ColourShift will restore my original resolution of 1024x768 (which the Display Manager will not do for you).

ColourShift is only designed to work with the standard set of modes, i.e. 480x352, 640x480, 800x600, 1024x768 and 1280x1024. If you have a non-standard mode defined which is not in this list, you may find that using ColourShift causes the computer to revert to the nearest standard mode.

Running ColourShift from the RISC User menu system opens a directory viewer containing the ColShiftRM module. Double-clicking on this installs the module ready for use. You can of course transfer the module to a suitable place on your hard disc and run it as part of your boot sequence. If you have a Risc PC, putting the module into the directory !Boot.Choices.Boot.Tasks will ensure that it is run automatically.

Once it is installed, all you need to do to change the colour depth on your screen is to press the Alt key together with either the plus or minus key on the keypad. As you might expect, plus increases the colour depth while minus decreases it.

ColourShift takes its default resolution the currently configured start-up resolution (i.e. the value given in the file !Boot.Choices.Boot.PreDesk.Configure. If you subsequently change resolution manually and then use ColourShift, it will therefore restore the original configured resolution.

Copyright  RISC User 1996
