Texas Instruments 990 Manual page 38

~----9_4_54_2_4_-9_1_01
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XO
Xt
X2
X3
X4
X5
X6
X7
XB
10
Figure 1-19. United States Model 911 VDT Keyboard with Keys Numbered
Table 1-4. Contact Matrix Connections and Associated Diodes for United States
and European Mode! 911 VDT Keyboards
YO
Yl
Y2 Y3 \' 4
y::;
Y6 Y7
YB
Y9
11 32 52 72 1 2 33 53
73
54
74
cR 1 2
I
CR 1 3
I
cR 1 4
!
cR 1
51
CR 1 6 CR t 7
I
CR 1 8
I
cR 1 9 cR 20 cR 21
1
CR8
87
CR78
2
CR7
I
69
CR79
l
3
CR9
4 5
6
CR 1 0 CR 1 1 CR 6
I
71
I
ICR81
l 1
49
CR82 CR83
50
I
7
CR5
8
CR4
9
CR3
10
CR2
I
51
I
29
I
30
I
3 1
I
CR84
I
CR85
I
CR86 CR87
l 1 l l
88
I
i
I
28
!
48
I
68
T
I
27
T
47
T
66
1
85
1
91*
I I ! ! I
CR68 CR69 CR70 CR71 CR72 CR73 CR74 CR75 CR76 CR77
26 46 65 84 25 45 64 83 24 44
CR58
I
CR59
I
63
CR48
21
82
CR49
41
CR60
I
CR61
i
81
II
62
CR50 . CR51
60 79
!
CR62
I
43
CR52
78
CR63
23
CR53
59
1,
CR64
I
CR65
l
80
' 1
61
CR54 CR55
40 20
!
CR66
I
42
CR56
90
CR67
22
CR57
77
CR38 CR39 CR40 CR41 CR42 CR43 CR44 CR45 CR46 CR47
58 39 19 76 .57 38 18 17 37 13
CR28 CR29 CR30 CR31 CR32 CR33 CR34 CR35 CR36 CR37
16 1 5 36 35 56
CR22 CR23 CR24 CR25 CR26
89*
CR27
*NOT INSTALLED IN EVERY CONFIGURATION
:A;l ::36268A
I
KEY
DIODE
KEY
DIODE
KEY
DIODE
KEY
DIODE
KEY
DIODE
KEY
DIODE
KEY
DIODE
KEY
DIODE
KEY
DIODE
1-28
Digitai Systems Division