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A-20
Table C-3 Continued
WY-99GT User's Guide
Command
Byte Format
Null+ Ollp
pppp
+
dddd dddd
Null+ SOH +
aaaa aaaa
Null +
lltn nnnn
+
rrrr rrrr +
cccc cccc
+
RRRR RRRR
+
cccc cccc
+
aaaa aaaa
Function
Controls port 1/0.
If p pppp
equals 4, then this
command writes to the control register of the port
where the data portion of the command
(dddd
dddd)
has this format:
Bit 7-Page select (only page 0 supported)
Bit 6-Not used
Bit 5-Enables text blinker
Bit 4-Not used
Bit 3-Screen enable
Bit 2-Not used
Bit 1-Enters graphics/clears screen
Bit 0-Clear, Hercules format set, CGA
format
Sets new character attributes where aaaa aaaa
designates the following attributes:
Attribute code
7 6 5 4 3 2 1 0
Blank
B 0 0 0 I 0 0 0
Underline
B 0 0 0 I 0 0 1
Normal display
B 0 0 0 I 1 1 1
Reverse video
B 1 1 1 I 0 0 0
where
I
=
0-Sets normal text
I
=
1-Sets bold text
B
=
1-Sets a blinking character if
the text blinker is enabled
B = 1-Sets a bold background if
the text blinker is not enabled
Scrolls the display where
t-Sets the scroll direction (1
=
up, 0
=
down)
n
nnnn-Defines the number of lines to scroll
up or down
rrrr
rrrr-Address of the upper left row
cccc cccc-Not used
RRRR RRRR-Address of the lower right row
CCCC CCCC-Not used
aaaa
a~aa-Attribute
of new lines inserted at
the top or bottom
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