Texas Instruments 990 - Model 911 VDT Keyboard Logic

......
I
v.
w
FROM CRU
INTERFACE
LOGIC
{
FROM TIME BASE
GENERATOR
FROM CRU
INTERFACE LOGIC
FROM VIDEO
LINE DRIVERS
(B) 136284
KEYBOARD
{
UART
CRA2Q
_,...-1
TRB
RR!
FROM CRU
4~
RR2
~
INTERFACE LOGIC
TR7
CRA3Q
TR6
~
RR3
TR5
RR4
_____.......
~
TR4
RR5
_____.......
"---
TR3
RR6
_____.......
TR2
RR7 r-
_/
TRI
RRB
/
o-
SFD
0 ----'
ROD
1-
PS
1-
WLSI
o-
SBS
KEYBOARD
o- F
1
1
KBPEL
ACKNOWLEDGE
PE
LATCH
FROM TIME BASE
HSQ
GENERATOR
t=
TC
FE
t--
KEYBOARD
i
ACKNOWLEDGE
KEYBOARD
SYNCHRONIZER
INTERRUPT
RC
OE
t--
LATCH
RESET LATCH
KBR DYL
L504 1-
CRL
DR
PRE
WORD IQ
J
Q
KBACKQ
D
Q
KBASQ
D
Q KEIAK'l.
NKBAKQ
KBTL
i5RR
-
TO
LS109 LS273 LS273
NCR13P -IO
CLK
RI
1-
WLS2
TBRE
KBTBREL
I-
-
1-K
Qt--
.--
CK
,...--
CK
,...---
i'BRL
MR
TRE
1--
J
CLR
CL CL
~
FROM CRU
CRA9Q
INTERFACE
NDOT4
LOGIC
FROM TIME
HSQ
NRL
BASE
GENERATOR
BKBINL.
FROM CRU
RL
INTERFACE
LOGIC
Figure 1-34. Model 911 VDT Keyboard Logic
KBD, 0-7 ,Q
TO CRU
INTERFACE
LOGIC
1
TO CRU
l
INTERFACE
LOGIC
PRE
1 --1 J
LS109
-C CLK
TO VIDEO
LINE DRIVERS
1 ---1K
CLR
~
~NKBTBRL
~
,.......-
-
LS02
~
NRKBL
----
Q
KBDRQ
-
Q~
TO CRU
INTERFACE
LOGIC