Picasso96Mode

Picasso96Mode is the preferences tool to create and adjust display modes. It is normally installed in SYS:Prefs. The GUI looks like this:

The GUI is divided into four areas:

The action buttons

In the upper right corner you can see four drag-and/or-drop boxes which allow you to:

create a new object (can be setting, resolution or mode depending on which listview you drop it into),
copy an object to the internal clipboard for later use,
duplicate an object and
delete an object.

The list of settings

A setting consists of all display resolutions for one Picasso96 graphics board. In the listview you see the currently available settings in your settings file. The strings in the settings listview consist of the card type, for which of possibly multiple boards of the same type this particular setting is (normally 1 i.e. for the first board of that type) and a user selectable name for this setting.

The resolution list

This list contains all different resolutions that are currently configured for your system. You can see the dimensions, the display ids and the current state (active or inactive). Below you see gadgets for width, height, name and base display id. Width and height are only changeable when there is no mode defined for that resolution. Only the upper half of the display id is changeable due to graphics.library's display id management.
You can toggle the activation state of any entry by double clicking on it. An inactive resolution will not be added to the system.

The mode section

This section consists of the list of modes for the current resolution and the edit section for the current mode. You can define multiple modes of the same depth type, but only the first active mode will be used for display. Here, too, you can toggle the activation state by double clicking on it.

Description of the edit section gadgets

Depth

Planar
if defined, screens with upto 16 colors will be planar. This only makes sense for old boards without blitter like e.g. the Domino. On other boards these modes are considerably slower than chunky modes and should only be used when necessary.
Memory usage: 0.5 Bytes/pixel.
Chunky
CLUT (color look-up table) based modes with upto 256 colors. These are the fast, memory saving and very compatible modes for all purposes.
Memory usage: 1 Byte/pixel.
HiColor
when fast display is wanted but more than 256 colors are needed for pictures, HiColor is a good choice. On modern chip sets these modes are almost as fast as chunky but offer near TrueColor picture quality with 65536 (16bit) or 32768 (15bit) different colors. You might even want to use HiColor for your Workbench screen if you like to use fancy backdrops.
Memory usage: 2 Bytes/pixel.
TrueColor
when fine color details are important, TrueColor with its 16 million different color shades is the way to go. But be warned that TrueColor displays need more memory and are considerably slower than those using HiColor.
Memory usage: 3 Bytes/pixel.
TrueAlpha
some boards use 32 bits per pixel for TrueColor displays although most of them ignore the extra 8 bits. This mode has certain advantages but also disadvantages over the 24 bit TrueColor modes. Writing single pixels is considerably faster because only one longword access has to be performed instead of three single byte accesses, but due to the increased size of the bitmaps more memory is needed and blitting areas can be slower.
Memory usage: 4 Bytes/pixel.
Clock
Pixelclock of the current mode, this has direct effect on the horizontal and vertical refresh rates of the mode.
Interlace
Activating this flag causes the display to become interlaced, i.e. the odd and even lines will be displayed in two different frames thereby doubling the vertical refresh rate but resulting in the well known interlace flicker. This might be used for high resolution screens on boards and monitors which do not support high horizontal refresh rates.
DoubleScan
This flag on the other hand results in each line being displayed twice during each frame resulting in a effectively halved vertical refresh rate. This is normally used for screens with less than about 350 lines.
Timings
Here you can see the actual values for the current mode. These values are in pixels or lines respectively. On most boards the horizontal timings are always multiples of eight because of historical reasons the horizontal values are not pixel but instead so-called character clocks (i.e. 8 pixel units).

FrameSize
These values contain the entire frame size including the invisible areas during the retrace periods. They are usually about 25% larger than the actual display size for horizontal value and about 10% for the vertical.
BorderSize
This is the width or height of a visible border around the display. It will only be visible if you set it greater zero and disable border blanking. Usually you will set it to zero.
Position
These values determine the position of the display on the monitor.
SyncSize
These values determine the length of the respective sync impulse. You will only have to increase it when your monitor has problems with the default values.
SyncPolarity
Some monitors determine their display parameters from the polarities of the sync signals. Unselected gadgets stand for positive syncs and selected for negative. Negative syncs are default. If your monitor does not allow to adjust the display to what you want you might try to change the polarities.
Frequency
Here you can see the effective horizontal and vertical refresh rates in kHz and Hz respectively. These give you a rough impression about the validity of the current mode. The refresh rates are calculated by evaluating these functions:
- horizontal frequency = pixelclock / horizontal framesize
- vertical frequency = horizontal frequency / vertical framesize
Test
This button brings up a test screen with a test pattern which allows you to check the display geometry. You can not change any of the display parameters in this test mode.
Edit
With this button you bring up an edit screen containing a small help text and a window containing the same gadgets as the timing section of the main Picasso96Mode window. In this mode you can change the display parameters, see the new parameters and verify the result immediately. Pressing ESCAPE leaves the edit mode discarding changes, pressing RETURN leaves accepting changes. If you press a mouse button the edit mode is left, too, and you will be asked later whether to accept or discard any changes.
Use
If you changed anything in the current mode you can press the use button to update the mode within its resolution. You will be asked whether you want to discard changes when you select a different mode, too.
Undo
With this button you can discard all changes made to the current mode.

If you want more informations about the details, read Sylvain Bourciers Picasso96 ScreenMode Definition FAQ.

Usage of the drag-and-drop style interface

The way settings, resolutions and modes are handled is quite the same and therefore I now just call them objects and explain how to use any of them. You can create, delete or copy any object by performing simple operations with the mouse.

Creating a new object:
Click on the create button which is the first button in the upper left corner of the main Picasso96Mode window. You will see that a small rectangle with the text "New Object" will appear under your mouse pointer as long as you keep the left mouse button pressed. When you now move the mouse pointer around on the display you will notice that the rectangle will move along and will be clipped if you try to leave the window. If you are within the borders of one of the list you will see that the text box changes. If you drop the box now, i.e. release the left mouse button you will get a new item in the list you dropped the object into.
Deleting an object:
Let's assume you want to delete an object from one of the lists. All you have to do is to click on the entry within its list and drag the mouse outside to the left or right of the list view while holding the left mouse button pressed. If you are too slow, the action will be ignored and you'll have to retry. Now you will see a text box under your mouse pointer representing the object you currently work with. If you now drag the mouse over the delete gadget which is the fourth of the gadgets in the upper left corner of the window and release the left mouse button, this object will be deleted from its list. It is now completely gone. No, there is no undo button...
Duplicating an object:
If you want to get a copy of an object, for example to create the matching mode for a different color depth, you drag the original object over the third gadget in the upper left corner of the window. Once there, you release the left mouse button and will see that a copy of the original object will be added to the bottom of the list you got the object from. This is now a copy of your original object.