Texas Instruments 990 - Page 34

~~-------------------
~ 945423-9701
COMPUTER MEMORY WORD
SELECTA-(CRU PORT SELECT
FOR VDT 0)
SELECTA-(CRU PORT SELECT
FOR VDT 0)
* JAPANESE KATAKANA MODELS
ALPHANUMERIC MODE=O; KATAKANA MODE= 1
(A) 134317A
CRT CONTROLLER
CRU BITS
o DISPLAY MEMORY READ DATA LSB
2
3
•
4
5
6
DISPLAY MEMORY READ DATA MSB
7
HIGH INTENSITY=O; LOW INTENSITY~ 1 *
•
8
KEYBOARD DATA LSB
9
A
B
•
C
D
E
KEYBOARD DATA (MSB-l)
F
KEYBOARD DATA READY
0
CURSOR ADDRESS LSB
2
3
•
4
5
6
7
•
8
9
A
CURSOR ADDRESS MSB
B
KEYBOARD DATA MSB
•
C
TERM INAL READY (READY
cO IOFFLINE~I)
D
PREVIOUS STATE FLAG OR
SELF-TEST
E
KEYBOARD PARITY ERROR
F
KEYBOARD DATA READY
Figure 3-1. Computer Input Bit Assignments for Terminal 0
3-2
Digital Systems Division