THE BEEBUG VIDC MODE EXPANDER ============================= Please remember that this documentation is pre-release and very temporary. In particular, the fitting instructions are very terse, and assume a knowledge of dismantling and reassembling the Archimedes. Should you have any problems please contact Beebug on 0727 40303. DISC CONTENTS ------------- This disc contains, in addition to this file, the !ModeEd mode definer application, and a set of new mode modules in the sub-directory 'Modules'. This contains mode modules for the Taxan 770, 775 and 795. The 775 module is also suitable for the Eizo 9060, and the 795 module for the Eizo 9070. The appropriate module can be loaded by double clicking on it, and a list of available modes obtained by using *HELP MODES. Hard disc owners can arrange for the appropriate module to be loaded as part of the boot sequence, and the mode modules can be editted using !ModeEd (see below). INSTALLATION ------------ The VME fits onto the Genlock links of PL4 (400/1) or PL3A (310 & 440), and is positioned so that the circuit board covers the rest of the pads of the connector, which in most machine do not have pins fitted. If there are pins fitted then they should be removed. The power flying lead from the VME should be piggy-backed onto the +5V connector (RED) either on the main board or the backplane. Finally, the control wire should be soldered onto the middle pin (pin 3) of the 'Aux I/O' connector to the lower left of the circuit board. On an A3000, the VME fits on LK28 and LK29 (lower right under keyboard), and faces right, having removed LK30. The control lead has to be soldered directly to pin 17 of IC18. !MODEED ------- ModeEd is a utility for creating and editing new screen modes for use under Risc OS on an Archemedes with or without a video speed up circuit fitted. The screen modes editor also allows more than just a single mode to be defined, making it posible to create a series of screen modes to suit various different applications of your computer. Running the modes editor for the first time To run the modes editor, double-click on the !ModeEd icon and it will appear on the icon bar. When you first run the modes editor, you may need to configure it to the facilities available on your system. This is done by clicking the menu button over the !ModeEd icon on the icon bar. A menu with three choices will appear. The first, 'Info' will display infomation concerning the version number of the mode editor when the pointer is moved over the sub-menu arrow. The last choice will exit the program and remove the icon from the icon bar. If, when you choose 'quit', you have an unsaved screen modes module loaded, you will be asked to confirm that you really want to quit. The second choice leads to a submenu containing three configuration options. The first tells the system that you do not have the video speed up hardware fitted. The second choice is used when you have a multi-sync monitor (eg Taxan 770, 775, NEC MultiSync etc) that is capable of displaying the non-multisync modes. The third option tells the system that you have a monitor that is not capable of displaying non-multisync modes (eg Taxan 795, Eizo 9060 etc). When you enter this menu, you will notice a tick displayed next to the current chosen configuration. Using the Screen Modes Editor To enter the screen mode editor, either click with select or adjust on the !ModeEd icon, or drag a modes module from a filer window onto the !ModeEd icon. Either of these actions will cause the mode editing window to open. If you have loaded a screen modes module, you will see the name of the module displayed in the module name icon. This may be changed by clicking on it to get the caret in this box and typing in a new name. Down the left side of the editing window there is a column of parameter boxes with headings on the left, and adjust arrows on the right. Values may be typed directly into the parameter box after first clicking with select or adjust over the box to cause a red caret to appear in it, and then typing in the required value. You do not need to press return after typing in a new value, but doing so will move the caret to the next parameter box. The up and down cursors keys may also be used for moving the caret around the window. The adjust arrows allow you to change the values using the mouse. Clicking select over an up arrow increases the value, while over a down arrow decreases te value. Clicking with adjust reverses the action of the select button. The first parameter box is for changing the mode number of a new mode. This can take a value between 0 and 127. Note however that values below 29, except 22 are used for the default screen modes provided by Risc OS. Although it is possible to redifine these modes, the screen format and number of colours must be the same as the existing Risc OS mode. A list of this modes can be found on page 453 in the Risc OS User guide. Also the mode editor uses Mode 127 for testing newly defined screen modes and so it should not be redefined. Columns and Rows define the size of the screen in terms of text characters. The number of pixels horizontally and vertically will be eight times the number of columns and rows respectively except when the 'Text gaps' option has been selected, when the number of pixels vertically will be ten times the number of rows. The next four parameters control the position and size of the screen with respect to the monitor in units of pixels. Increasing the 'Right' parameter moves the right hand side of the screen inwards, increasing the 'Left' parameter moves the left hand side inwards, increasing 'Top' brings the top of the screen down and increasing 'Bottom' brings the bottom of the screen up. To retain a good square image, right and top should not be decreased below 8 and 12 respectively. X board and Y border control the width of the horizontal and vertical borders in units of pixels. In the center of the editing window are two more parameter boxes, XEigfactor and YEigfactor. These control the convertion of OS co-ordinates to actual pixel co-ordinates. Normally you will set these to 1 and 2, but for double height characters as used by mode 20, you can change the YEigfactor to 1. Above these parameter boxes are icon for selecting the number of colours to use. The current option is highlighted in green. To select a different option, simply click with select or adjust over the appropriate number. Above the colours are the pixel rate options. These effectivly control the resolution that can be achieved. The pixel rate should be selected to produce a frame rate that is near to, but above 50Hz and a line frequency between about 20 and 35KHz. The 18MHz and 36Mhz options are only available with the Video speed up hardware fitted. In the top right corner of the window is an icon labelled 'Text gaps'. This controls the way in which text is displayed in normal text mode, (ie not in the wimp, but at the supervisor or basic prompts.) When selected, a gap of two pixels of inserted between each line of text to make it easier to read. This feature, for example is used by mode 17. When this feature is used, it is still posible to display graphics. Along the bottom of the window are three icon buttons labelled 'OK', 'Save' and 'Cancel'. The 'OK' button is used to test the screen mode being currently edited by switching to the newly defined mode. Note however that the mode that appears in the mode parameter box is not the mode that is actually used. Instead mode 127 is used. This has been done to enable editing of modes with the same number as one already present in another modes module that is active in memory. This use of mode 127 does not apply when editing existing Risc OS screen modes so that you can ensure that you have the correct format and colours parameters set. 'Save' adds the newly edited modes to the list of those to be saved in the module being currently edited. 'Cancel' is used to return to the screen mode in which !ModeEd was started up. This is mainly used to recover from a test mode that is out of sync or otherwise unusable. As under such circumstances it would probably be rather difficult to move the pointer over this icon, the Escape key, or function key f3 may be pressed as an alternative. Also F1 is an alternative to the 'OK' button and F2 is an alternative to the 'Add' button. Above these icon buttons are three lines of status information about the mode you are currently editing. The line frequency and frame rate should be kept approximately within the bounds mentioned in the section above concerning the pixel rate. The VIDC data rate can be used as a rough guide to the effect on the processing speed of your computer when the mode is used. The higher the number, the slower your computer will operate. For example something that takes about a second or so in mode 0 which has a VIDC data rate of 2Mb/s will take about three or four times that in mode 21 which has a VIDC data rate of 24Mb/s. The effect of this will be considerably reduced when an Arm 3 processor is used. Editing more than one mode As mentioned earlier, the modes editor allows you to edit more than just a single screen mode. In fact you can edit as many modes as you like and save the complete set as a single module that will, once loaded and active, allows you to use any of the modes you have created. This facilty is accessed by clicking the menu button over the editing window. This will produce a menu with the following choices: Edit mode, Add mode, Delete mode and Save RM. The edit and delete choices lead to submenus listing all the modes currently in the module. To add a mode to the list you can either select the 'Add' option in the editing window, or choose 'Add mode' from this menu. To choose a mode for editing, simply click on your choice from the submenu accessed by moving the pointer over the right-arrow next to 'Edit mode'. This will then copy the parameters for that mode into the editing window allowing you to edit and save them back into the list. Deleting a mode is very similar, simply choose the mode you wish to delete, and click over it. If the adjust button is used, the menu will remain active allowing you to quickly delete a number of modes. Saving your module Once you have finalised your list of modes, you will want to save them. If you are editing an existing modes module, then clicking over the Save RM choice will save the newly edited module in place of the original. To save a new module, move the pointer over the right-arrow next to 'Save RM' and drag the module icon to the required directory viewer. Once a module has been saved, it may be used. Within the wimp, a module may be loaded and activated by double clicking on its icon in a directory viewer. You can then use the wimp palette menu to choose on of your new modes. Loading modules into the editor To Load a module into the editor, drag it icon from a directory viewer window onto either the !ModeEd icon on the icon bar, or into the Editor window. You will see the name of the loaded module in the Module name box at the top of the editor window. Modes Module commands --------------------- When a modes module has been loaded, the following commands are available: *WimpMode This command sets the screen mode to be used by the desktop. is the number of any mode that is suitable for use by the wimp. This command is probably most usefully used in an Obey file used to customise the desktop by selecting your preferred mode and loading in some most commonly used utilities. *Mode This commands sets the current screen mode for use at the supervisor prompt (ie not in the wimp). is any defined mode number. This command is exactly equivelent the BASICs MODE statement. *Help Modes This commands produces a list of all screen modes modules and the mode definitions each contain. *Configure VIDCSpeed This command is used to configure the Video speed up hardware and monitor type options as follows: '0' tells the system that you do not have the video speed up hardware fitted. '1' is used when you have a multi-sync monitor (eg Taxan 770, 775, NEC MultiSync etc) that is capable of displaying the non-multisync modes. '2' tells the system that you have a monitor that is not capable of displaying non-multisync modes (eg Taxan 795, Eizo 9070 etc). When you enter this menu, you will notice a tick displayed next to the current chosen configuration. *Status VIDCSpeed This command displays the current configuration setting.