Modus Operandi  -  A quick mode changer

by Carl Stockton

This program is intended for the Risc PC only.

The Risc PC can access an almost infinite range of screen modes by virtue of the fact that you can change mode by specifying all the parameters of the mode required, rather than just a range of preset mode numbers as before. However, this means that to set the mode in the normal way using the Display Manager, it can require up to six mouse clicks. This is very inconvenient if you change mode a lot as I do (for example, I prefer to work in a 1024x768 mode most of the time, but my 1Mb of VRAM won't support 32000 colours in this mode, so as I do a lot of work with images I constantly need to switch to an 800x600 by 32000 colour mode).

To overcome this I have written Modus Operandi, an updated version of a program I have been using for the same purpose on an earlier machine for years now. It allows you to change mode by using Shift-Alt together with the numeric keypad. On earlier machines this simply meant typing the mode number on the keypad, but with the Risc PC this will only work for the 49 predefined mode numbers. Modus Operandi therefore also includes a setup program which enables you to map your own favourite modes to numbers above 49, and then simply change mode using those numbers in conjunction with Shift-Alt.

Running the item from the RISC User menu system opens a directory viewer containing the Modus application. This should be transferred to your hard disc. The functions of the program are actually performed by a relocatable module called Modus. However, you must install the module by running the application that contains it; this is because it requires a data file to be loaded and this file must always be located in the same place.

As supplied on the disc, Modus will recognise the 49 mode numbers built into RISC OS 3.5. If you wish to define your own mode numbers above this you must first run the setup application, which is called ModusSet and is located inside the !Modus application directory.

So the first step is to open !Modus by double-clicking with Shift held down. Now run ModusSet by double-clicking on its icon. An icon will be installed on the icon bar. Clicking Menu over this icon opens a menu with two options, Info and Quit, which perform their usual functions.

Clicking Select over the icon bar icon opens the setup window. At the top is a writable icon labelled Keypad number. You should enter into this icon the number that will activate the mode required when it is typed on the keypad. The default number is 50 as this is the first undefined number in RISC OS 3.5. You can also use the arrow icons alongside to alter the number in the writable icon.

Below this is an icon showing the number of colours that will be assigned to the mode. Alongside this is a popup menu icon; clicking over this allows you to choose from the available range, exactly as you do with the Display Manager.

Next are two more writable icons giving the X and Y resolution of the required mode. You should enter the required values into these icons.

At the bottom of the window are three action icons. Cancel removes any alterations you have made to the current mode number and restores the original values. Set sets the values for that mode number and moves on to the next mode number (pressing Return in the last writable icon has the same effect). Save choices saves all the data you have entered so that it can be used with Modus.

So if your favourite mode is 1024x768, you could arrange for mode number 50 to activate a 1024x768 by 16 colour mode, and for 51 to give you 1024x768 by 256 colours, for example. Don't forget to click on Save choices when you have defined all the required modes, otherwise you will not be able to access them from Modus. Bear in mind also that if Modus is already running when you use ModusSet to redefine mode numbers, you must kill the Modus module and run the Modus application again before you can use the new modes.

To run Modus itself, simply double-click on the !Modus icon in a directory viewer. The module will be installed. To change mode, just hold down Shift-Alt and enter the required mode number on the numeric keypad before releasing Shift-Alt.

Most users will find it helpful to run Modus as part of their boot sequence to ensure that it is always available.

Copyright  RISC User 1995
