Block Diagram - Control Data Corporation INFORMATION SYSTEMS TERMINAL II Hardware Maintenance Manual

CLOCK (4 MHz)
REFERENCE ONLY
ADDRESS
DATA (OUT PU T)
EXTERNAL WRITE
-1
2~0
r
INPUT
-------, -
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- ----
EXTERNAL OUTPUT
OUTPUT
250
t-
EXTERNAL READ
DATA (INPUT)
GATE EXT READY
I
1->0
14-
>0-.1.--__
EXTERNAL READY
TIMEOUT STATUS
.. 141t-----
54J,lS t 20%
------I~~
NOTE: ALL TIMES IN NANOSECONDS UNLESS STATED OTHERWISE.
Figure 4-15. External Input or Output Timing
(Timeout Condition)
VIDEO BOARD
03341-1
The video board provides timing and memory capabilities to
support the controller board and the display module. A
block diagram of the video board is illustrated in fig-
ure 4-16. The following is a list of some of the features
provided by the video board:
• 32K 8-bit words of RAM for crt refresh
• 16K 8-bit words of RAM for programs (basic memory)
• Provision for 16K 8-bit words of RAM expansion
4-26 82100083