17
APPENDIX B: Block Diagram
Appendix B: Block Diagram
PAPER END
SELECT
AUTO LINE FEED
ERROR
INITIALIZE PRINTER
SELECT INPUT
GROUND
6
4
8
20
5
3
2
7
SERIAL
INTERFACE
DB-25
CONNECTOR
DCE/DTE
DETECTOR
CONTROL
STATUS
LED
2
3
4
5
6
7
8
9
PARALLEL
INTERFACE
DB-25
CONNECTOR
1
10
11
12
13
14
15
16
17
18—25
DATA BIT 1
DATA BIT 2
DATA BIT 3
DATA BIT 4
DATA BIT 5
DATA BIT 6
DATA BIT 7
DATA BIT 8
STROBE
ACKNOWLEDGE
BUSY
DSR
RTS
DCD
DTR
CTS
RD
TD
GND
100K
PULL UP
NETWORK
PARALLEL
AND
SERIAL
PROCESSOR
REGULATOR
WITH
RESET
MONITOR
RESET
DIP SWITCH
SETTINGS FOR
RATE/LENGTH/PARITY
POWER
SUPPLY
8
3
2
20
6
4
5
DCD
RD
TD
DTR
DSR
RTS
CTS
9
+VIN
+V
-V
+5V