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Author : TetiSoft
Article ID : 21
Audience : Default
Version 1.00.02
Published Date: 2007/9/21 15:40:23
Reads : 2656

$VER: ScreenModes.doc 52.2 (6.6.2007)

How to define Picasso96 screenmodes

The new default method to define the screenmodes to be used by
Picasso96 is to edit the tooltypes of the P96 monitor icons in
Devs:Monitors/. The old method, using Picasso96Mode, does still
work, however, Picasso96Mode will not recognize the modes created
with the new method. Picasso96Mode offers more control of details
but is a bit complicated for the normal user.

Picasso96Mode adds a SETTINGSFILE tooltype to the monitor driver icon which
points to the modes stored in a binary file. The settings file screenmodes
are added before the tooltype screenmodes, the tooltype screenmodes dont
overwrite existing similar modes. So when you want to switch to the new
method completely, dont forget to remove the SETTINGSFILE tooltype.

You should first tell Picasso96 about the supported frequency ranges
of your monitor, then define screenmodes, then save and reboot
(the tooltypes are read during Picasso96 startup only).

Caution, dont store monitor driver backups in Devs:Monitors/.
Most existing monitor driver icons contain the BOARDTYPE tooltype
which overrides the filename and specifies which card driver shall
be used, it would be "random" which driver is found and used first,
so if they conflict the correct driver tooltypes could not be able to
redefine the modes already specified with the wrong tooltypes from
the backup. You can exclude file names on the commandline of the
LoadMonDrvs command call in Startup-Sequence but thats not recommended,
please store your monitor driver backups in SYS:Storage/Monitors/.

If you try to define a screenmode which would be out of the specified
monitor frequency ranges, Picasso96 will reject that screenmode.

If you try to define a screenmode which would be out of the capabilities of
your graphics card, Picasso96 will either try to adjust it (by e.g.
switching to DoubleScan mode or lowering the vertical sync rate if
possible) or reject it (e.g. it will not accept 24bit/32bit modes on old
graphics cards which dont support that).

The monitor driver tooltypes for defining monitor specifications are:

The minimum horizontal sync rate in Hz which is supported by your monitor.
The default value is 31500. The lowest possible value is 15000. Please
check the manual of your monitor for the correct value (its mostly
specified in kHz so you have to multiply it with 1000, 31500 means 31.5

Similar to HSYNCMIN, it specifies the maximum horizontal sync rate in Hz.
The default value is 38000 (38 kHz). The value must be greater than

The minimum vertical sync rate in Hz which is supported by your monitor.
The default value is 60. The lowest possible value is 50. Please
check the manual of your monitor for the correct value.

Similar to VSYNCMIN, it specifies the maximum vertical sync rate in Hz.
The default value is 75. The value must be greater than VSYNCMIN.

The monitor driver tooltype for defining screenmodes is:

With this tooltype you specify at least the width and height in pixels
and the vertical sync frequency in Hz of a screenmode. Example:


This will create a screenmode with a width of 1280 pixels, a height of
1024 pixels and a refresh rate (vertical sync rate) of 60 Hz.

When you are unsure about the widths, heights and frequencies to use,
consult the manual of your monitor, it often contains a list a supported
screenmodes. Of course its possible to create more modes when your monitor
has real multisync capabilities. Some hints:

Typical resolutions and frequencies supported by many monitors are

640x350@85 (37.9kHz)
640x400@85 (37.9kHz)
640x480@60 (31.5kHz)
640x480@72 (37.9kHz)
640x480@75 (37.5kHz)
640x480@85 (43.3kHz)
720x400@85 (37.9kHz)
800x600@56 (35.2kHz)
800x600@60 (37.9kHz)
800x600@72 (48.1kHz)
800x600@75 (46.9kHz)
800x600@85 (53.7kHz)
1024x768@60 (48.4kHz)
1024x768@70 (56.5kHz)
1024x768@75 (60.0kHz)
1024x768@85 (68.7kHz)
1024x768i@43 (35.5kHz)
1152x864@75 (67.5kHz)
1280x960@60 (60.0kHz)
1280x960@85 (85.9kHz)
1280x1024@60 (64.0kHz)
1280x1024@75 (80.0kHz)
1280x1024@85 (91.1kHz)
1600x1200@60 (75.0kHz)
1600x1200@65 (81.3kHz)
1600x1200@70 (87.5kHz)
1600x1200@75 (93.8kHz)
1600x1200@85 (106.3kHz)
1792x1344@60 (83.6kHz)
1792x1344@75 (106.3kHz)
1856x1392@60 (86.3kHz)
1856x1392@75 (112.5kHz)
1920x1440@60 (90.0kHz)
1920x1440@75 (112.5kHz)

With the old style CRT (Cathode Ray Tube) monitors, a higher refresh rate
results in less flicker. A too high refresh rate may however result in lower
display quality when you have a cheap monitor cable (or even a monitor switcher
inbetween the graphics card and the monitor) or you are running near the upper
limit of graphics card or monitor. Most people are happy with about 70 or 75 Hz.

With the new style digital TFT/LCD monitors, a higher refresh rate will not
result in less flicker anymore because the monitor refresh rate differs from
the graphics card refresh rate. Here you should probably follow the
recommendations from your monitor manual, often any refresh rate between 60
and 75 Hz is accepted.

On digital TFT/LCD monitors, you should prefer the exact physical resolution of
your monitor as default screenmode, then one pixel in your graphics card can be
displayed as one pixel on your monitor. Any other resolution will result in
interpolated pixels on your monitor which often causes moiree effects or a
blurry display. Check the monitor manual for the exact physical resolution.
When you want to use lower resolutions on a TFT/LCD, its often a good idea to
use something which can be scaled with an integer number, e.g. when you use
640*480 on a 1280*960 monitor, the monitor can display each graphics card pixel
with exactly four (2*2) of its own pixels. Using higher resolutions only makes
sense for displaying large pictures in fullscreen mode when your picture viewer
is unable to scale down the picture.

Back to the explanation of the MODE tooltype, for interlace mode you can specify
an "i" behind the refresh rate, e.g. 'MODE=1280x1024@60i'. BTW, doublescan mode
is automatically activated when the horizontal frequency of the given mode drops
below HSYNCMIN, but its also possible to activate it with a "d" behind the refresh

By default, each mode will be created in all available color depths.
You can add a list of depths separated by commas to a mode specification
to create a mode with only the specified depths. Example:
MODE=1280x1024x8,16@60 will create the mode with depths of 8bit (256 colors)
and 16bit (65536 colors), but not with 15bit (32768 colors), 24bit or 32bit

Adding "-hsync" to a mode specification changes the horizontal sync polarity
from positive (default) to negative. Adding "-vsync" does the same for the
vertical polarity. This may be useful when you have lots of similar screenmodes
defined or a second computer attached to your monitor and the monitor is unable
to distinguish all modes in his internal settings tables for screen placement
etc, then the opposite polarity may help the monitor to distinguish screenmodes.
Example: MODE=1280x1024x24@75-hsync-vsync

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