31.469
31.778
3.813
1.589
26.058
0.318
70.086
14.268
0.064
1.716
11.504
0.985
25.175
Positive
Negative
Separate
fH (kHz)
A µsec
B µsec
C µsec
D µsec
E µsec
fV (Hz)
O msec
P msec
Q msec
R msec
S msec
Clock
Frequency
(MHz)
Polarity
H.Sync
V.Sync
Remark
IBM
2 Product Specifications
GH15LS/GH15ES/GH15MS
2-3
Q
R
S
P
O
Video
Sync
Sync
Horizontal
Vertical
C
D
E
P
O
B
A
Video
Sync
Sync
Separate Sync
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.
C
D
A
O
E
B
P
Video
Sync
Sync
Video
Q
R
S
A : Line time total
B : Horizontal sync width
O : Frame time total
P : Vertical sync width
C : Back porch
D : Active time
Q : Back porch
R : Active time
E : Front porch
S : Front porch
VGA3/60 Hz
640 x 480
640/72 Hz
640 x 480
640/75 Hz
640 x 480
800/56 Hz
800 x 600
800/60 Hz
800 x 600
VGA1/70 Hz
640 x 350
VGA2/70 Hz
720 x 400
Table 2-1. Timing Chart
31.469
31.777
3.813
1.589
26.058
0.318
70.087
14.268
0.064
0.858
13.155
0.191
28.322
Negative
Positive
Separate
31.469
31.778
3.813
1.589
26.058
0.318
59.940
16.683
0.064
0.794
15.761
0.064
25.175
Negative
Negative
Separate
37.861
26.413
1.270
3.810
20.825
0.508
72.809
13.735
0.079
0.528
13.100
0.026
31.500
Negative
Negative
Separate
37.500
26.667
2.032
3.810
20.317
0.508
75.000
13.333
0.080
0.427
12.800
0.027
31.500
Negative
Negative
Separate
35.156
28.444
2.000
3.556
22.222
0.667
56.250
17.778
0.057
0.626
17.067
0.028
36.000
Positive
Negative
Separate
37.879
26.400
3.200
2.200
20.000
1.000
60.317
16.579
0.106
0.607
15.840
0.026
40.000
Positive
Positive
Separate
Mode
VESA
Timing
Summary of Contents for GH15ES
Page 11: ...Memo 3 Disassembly and Reassembly 3 4 GH15LS GH15ES GH15MS ...
Page 14: ...4 Troubleshooting GH15LS GH15ES GH15MS 4 3 1 5 6 7 2 3 4 WAVEFORMS ...
Page 18: ...GH15LS GH15ES GH15MS 5 1 5 Exploded View and Parts List 5 1 GH15LS GH15ES ...
Page 19: ...5 Exploded View Parts List 5 2 GH15LS GH15ES GH15MS 5 2 GH15MS ...
Page 26: ...GH15LS GH15ES GH15MS 7 1 7 Block Diagram ...
Page 27: ...7 Block Diagrams 7 2 GH15LS GH15ES GH15MS Memo ...
Page 28: ...GH15LS GH15ES GH15MS 8 1 8 Wiring Diagram ...
Page 29: ...Memo 8 Wiring Diagram 8 2 GH15LS GH15ES GH15MS ...
Page 31: ...9 2 GH15LS GH15ES GH15MS 1 5 6 7 2 3 4 9 Schematic Diagrams ...
Page 33: ...9 Schematic Diagrams 9 4 GH15LS GH15ES GH15MS Memo ...