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
IBM
VGA2/70 Hz
720 x 400
Timing
fH (kHz)
31.469
A µsec
31.777
B µsec
3.813
C µsec
1.907
D µsec
25.422
E µsec
0.636
fV (Hz)
70.087
O msec
14.268
P msec
0.064
Q msec
1.080
R msec
12.711
S msec
0.413
Clock
Frequency
28.322
(MHz)
Polarity
H.Sync
Negative
V.Sync
Positive
Remark
Separate
Separate Sync
Horizontal
Video
Video
C
D
C
D
E
Sync
Sync
Sync
B
B
A
A
A : Line time total
C : Back porch
E : Front porch
DP15H*/DP17L*
VGA3/60 Hz
640/75 Hz
640 x 480
640 x 480
31.469
37.500
31.778
26.667
3.813
2.032
1.907
3.810
25.422
20.317
0.636
0.508
59.940
75.000
16.683
13.333
0.064
0.080
1.048
0.427
15.253
12.800
0.318
0.027
25.175
31.500
Negative
Negative
Negative
Negative
Separate
Separate
Vertical
Video
Video
E
Q
R
Q
R
Sync
Sync
Sync
P
P
P
O
O
O
B : Horizontal sync width
D : Active time
Table 2-1. Timing Chart
640/85 Hz
800/75 Hz
640 x 480
800 x 600
43.269
46.875
23.111
21.333
1.556
1.616
2.222
3.232
17.778
16.162
1.556
0.323
85.008
75.000
11.764
13.333
0.671
0.064
0.578
0.448
11.093
12.800
0.023
0.021
49.500
36.000
Negative
Positive
Negative
Positive
Separate
Separate
S
S
O : Frame time total
Q : Back porch
S : Front porch
2 Product Specifications
VESA
800/85 Hz
1024/75 Hz
800 x 600
1024 x 768
53.674
60.023
18.631
16.660
1.138
1.219
2.702
2.235
14.222
13.003
0.569
0.203
85.061
75.029
11.756
13.328
0.056
0.050
0.503
0.466
11.179
12.795
0.019
0.017
56.250
78.750
Positive
Positive
Positive
Positive
Separate
Separate
P : Vertical sync width
R : Active time
1024/85 Hz
1024 x 768
68.677
14.561
1.016
2.201
10.836
0.508
84.997
11.765
0.044
0.524
11.183
0.015
94.500
Positive
Positive
Separate
2-3
Advertisement
Troubleshooting
