Advertisement
2-3 Timing Chart
This section of the service manual describes the timing that the computer industry recognizes as standard
for computer-generated video signals.
Mode
VGA2/
70 Hz
Timing
720 x 400
fH (KHz)
31.469
A µsec
31.777
B µsec
3.813
C µsec
1.589
D µsec
26.058
E µsec
0.318
fV (Hz)
70.087
O msec
14.268
P msec
0.064
Q msec
0.858
R msec
13.155
S msec
0.191
Clock
Freq.
28.322
(MHz)
Polarity
H.Sync
Negative
V.Sync
Positive
Remark
Separate
Separate Sync
Horizontal
Video
Video
C
D
E
C
D
E
Sync
Sync
Sync
B
B
A
A
A : Line time total
C : Back porch
E : Front porch
LW15E33C/LW17E34C
Table 2-1 Timing Chart
IBM
VGA3/
640/75 Hz
60 Hz
640 x 480
640 x 480
31.469
37.500
31.778
26.667
3.813
2.032
1.589
3.810
26.058
20.317
0.318
0.508
59.940
75.000
16.683
13.333
0.064
0.080
0.794
0.427
15.761
12.800
0.064
0.027
25.175
31.500
Negative
Negative
Negative
Negative
Separate
Separate
Vertical
Video
Video
Q
R
S
Q
R
S
Sync
Sync
Sync
P
P
P
O
O
O
B : Horizontal sync width
D : Active time
VESA
800/75 Hz
1024/60Hz
800 x 600
1024 x 768
46.875
48.363
21.333
20.677
1.616
2.092
3.232
2.462
16.162
15.754
0.323
0.369
75.000
60.004
13.333
16.666
0.064
0.124
0.448
0.600
12.800
15.880
0.021
0.062
49.500
75.000
Positive
Negative
Positive
Negative
Separate
Separate
H/V Composite Sync
A
Horizontal
Vertical
P
B
Sync-on-Green
Vertical
Green
Horizontal
P
Q
B
O : Frame time total
Q : Back porch
S : Front porch
2 Product Specifications
1024/75Hz
1280/75Hz
1024 x 768
1280x1024
(17" Only)
60.023
79.976
16.660
12.504
1.219
1.067
2.235
1.837
13.003
9.481
0.203
0.119
75.029
75.025
13.328
13.329
0.050
0.038
0.466
0.475
12.795
12.804
0.017
0.013
78.750
135.000
Positive
Positive
Positive
Positive
Separate
Separate
VIDEO
Q
S
R
O
R
S
O
P : Vertical sync width
R : Active time
2-3
Advertisement
