User`s manual

User's Guide
PASSTHROUGH = (YES¦NO)
Activates/deactivates the monitor passthrough
(This value is only valid with an existing
Monitorswitch/Flickerfixer)
BOOTLOGO = (YES¦NO)
Activates/deactivates the Bootlogo
MEMCLOCK = xx
Sets the speed tor the Graphics memory
(only valid tor a CyberVision64 graphics board)
SCROLLMASK = (YES¦NO)
Activates/deactivates the masking during panning.
RESOLUTIONS, COLOR DEPTH, FREQUENCIES
Before you change the default settings or the monitor type, please read through this chapter.
Line frequency, refresh rate, band width and colour depth are common terms that every
computer user has heard but may not fully comprehend.
Line Frequency: This defines how many times per second the electron rays must overwrite the
screen from left to right and back. The return ray is darker and is, therefore, not visible to the
observer. The line frequency is the product of the number of lines displayed (e.g. 768) and the
number of non-interlaced displays (e.g. 70), i.e. 53760, to which the synchronisation lines must
be added, resulting in approx. 54.5 kHz.
Refresh Rate: This value is also known as the vertical frequency and is the frequency with
which the segments of a monitor picture are written over each other. At a resolution of
1024x768 this value should be at least 70Hz.
Band Width: This defines the transmission rate of electronic circuits boards. In the field of video
band width is used to describe the frequency in which the pixels follow on from each other. The
higher the line/refresh frequency, the higher the band width must be to process them. Good
quality monitors have a band width of around 150MHz. It is always important to use high quality
VGA cable with high band widths, as the normal low cost cable significantly impairs the picture
quality above 70MHz. Modern graphics processors have band widths of 230MHz.
Colour Depth: This defines how many visible colours can be simultaneously displayed on your
screen. High colour depths require high band widths for the graphics processor, as a 24 bit
screen requires three times more graphics data than an 8 bit screen. The following section
shows how to set up the necessary graphics memory for the various resolutions and colour
depths of the CyberVision PPC.
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