Mode Register Summary; Status Register - IBM 5150 Hardware Reference Manual

Bit 5 When on, this bit will change the character background
intensity to the blinking attribute function for ALPHA
modes. When the high order attribute bit is not selected, 16
background colors (or intensified colors) are available. For
normal operation, this bit should be set to "1" to allow the
blinking function.
Mode Register Summary
Bits
0
1
2 3 4
5
0 0
1 1
0 1
40
x
25 ALPHA B & W
0 0 0 1 0 1
40
x
25 ALPHA COLOR
1 0 1 1 0 1
80
x
25 ALPHA B & W
1 0 0 1 0 1
80 x 25 ALPHA COLOR
0 1 1 1 0
z 320
x
200 B & W GRAPHICS
0
1
0
1
0
z
320
x
200 COLOR GRAPHICS
0 1 1 1 1 z 640
x
200 B
&
W GRAPHICS
'1'
4"
l"
~
.~
'1'
ENABLE BLINK ATTRIBUTE
640
x
200 B & W
ENABLE VIDEO
SELECT B
&
W MODE
SELECT 320
x
200 GRAPHICS
80
x
25 ALPHA SELECT
Z
=
don't care condition
*
THE LOW RESOLUTION 160 x 100 MODE REQUIRES SPECIAL PROGRAMMING
AND IS SET UP AS ALPHA MODE 40
x
25
Status Register
~
The status register is a 4 bit read only register. Its address is X'3DA'.
It can be read using the 8088 I/O IN instruction.
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