Sharp MZ-5500 - Page 97

°VMA
VMA i s the bias value which makes · the window area set to the respective
display area .
VRAM
c
T
~DAt-* - - - - -.,
I
I
L_
A
I
I
Area respective to
the display screen
VAD
VMA - VAD
WDA
In other words, the area A which
begins with WDA is displayed in
the area B which begins with VAD.
SAD is the display start
addr e ss to he set to GDC.
Fig.lS - 6
°VDS
VDS controls the VRAM plane output.
\
bit
2
1 0
VDS
I
I
I
'\ 1: For
the plane R
or one plane
For
the
plane G
For the
plane B
As shown above, VDS has three bits for ea ' ch window which are used to
perform any plane display or overlaid display of two or three planes.