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INT
52h,
Function 8
-
Set
Multiple Pixels to
Current
Attribute
Entry:
AH =8
(function
code)
BX =
number
of
pixels affected
Exit:
No
registers specified
This
routine turns
off
or
on
(depending on
the current graphics
attribute)
BX
pixels at
and
to
the
right of
the current graphics cursor.
For example,
if
BX =
2,
the
pixel
addressed by
the
graphics cursor
and
the
pixel
immediately
to
its
right
are
set to
the
current
graphics
attribute (0
or
1).
Notes
1.
The
graphics cursor
must be unchanged upon
exit
from
this
routine.
2
It
is
assumed
that
the
caller
will
never
specify
a
pixel
count
such
that
the operation
extends
beyond
the rightmost
pixel
of
the screen. Therefore
this
routine
need
not
check
for this
condition.
3.
It
is
assumed
that
the
caller
will
never
specify
a
pixel
count
of
0.
Therefore
this
routine
need
not
check
for this
condition.
4
This
routine
should
be
written
to
handle
multiple pixels
in
an
efficient
manner.
For
example,
all
affected pixels
in
a
given byte should
be handled
with
a
single fetch
and
store
of
the
byte
from video
memory.
In
fact,
if
all
the
bits
of
a given byte are
affected
it
is
not
even
necessary
to
fetch the
byte
from video
memory.
INT 52h,
Function
9
-
Read
Attribute of
Current
Pixel
Entry:
AH
=
9
(function
code)
E
X
j
t:
AL
=
external
attribute of pixel
for pixel
off,
1
for pixel
on
INT 52h, Function
A
-
Fetch Graphics Cursor
Entry:
AH
=
A
(function
code;
Exit:
BX
=
word 2
of
graphics cursor
CX =
word
3
of
graphics cursor
DX =
word
1
of
graphics cursor
145
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