IBM T T 541, Service Manual

Page: 4 / 35

TIMING CHART
- 4 -
VIDEO
SYNC
B
D
C
F
E
A
H / V
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
H (Pixels)
V (Lines)
Sync
Polarity
+
–
–
+
–
–
–
–
–
–
+
+
+
+
+
+
+
+
–
–
–
–
–
–
+
+
Dot
Clock
25.175
28.322
25.175
30.24
31.5
36.0
40.0
50.0
49.5
57.2832
65
75
78.75
Frequency
31.468 KHz
70.0 Hz
31.468 KHz
70.0 Hz
31.469 KHz
60.0 Hz
35.00 KHz
66.67 Hz
37.50 KHz
75.0 Hz
35.156 KHz
56.25 Hz
37.879 KHz
60.3 Hz
48.077 KHz
72.188 Hz
46.875 KHz
75.0 Hz
49.725 KHz
74.55 Hz
48.363 KHz
60.0 Hz
56.476 KHz
70.0 Hz
60.023 KHz
75.0 Hz
Resolution
640 x 350
720 x 400
(TEXT)
640 x 480
640 x 480
640 x 480
800 x 600
800 x 600
800 x 600
800 x 600
832 x 624
(MAC)
1024 x 768
1024 x 768
1024 x 768
Total
Period
( E )
800
449
900
449
800
525
864
525
840
500
1024
625
1056
628
1040
666
1056
625
1152
667
1344
806
1328
806
1312
800
Video
Active
Time ( A )
640
350
720
400
640
480
640
480
640
480
800
600
800
600
800
600
800
600
832
624
1024
768
1024
768
1204
768
Blanking
Time
( B )
160
99
180
49
160
45
224
45
200
20
224
25
256
28
240
66
256
25
320
43
320
38
304
38
288
32
Sync
Duration
( D )
96
2
108
2
96
2
64
3
64
3
72
2
128
4
120
6
80
3
64
3
136
6
136
6
96
3
Back
Porch
( F )
48
60
55
34
48
33
96
39
120
16
128
22
88
23
64
23
160
21
224
39
160
29
144
29
176
28
Front
Porch
( C )
16
37
17
13
16
10
64
3
16
1
24
1
40
1
56
37
16
1
32
1
24
3
24
3
16
1
MODE
1
2
3
4
5
6
7
8
9
10
11
12
13