Casio JD-5500 Service Manual page 18

Pin No. Signal
84 VSSR
85 ~ 108 C1 ~ 24
109, 110 S1, S2
111 ~ 205 S3 ~ 96
206 DUMMY
207, 208 XI, XO
209 DUMMY
210, 211 PO, PI
212 DUMMY
213, 214 PORT2,3
215 ~ 217 PORT4 ~ 6
218 PORT7
219 OPT2
220 OPT3
221 OPT4
222 OPT5
2. RAM (LC3564QM-85)
Pin No. Signal
1
2 ~ 10 A0 ~ 7, A12
11 ~ 13 I/O 0 ~ 2
14 GND
15 ~ 19 I/O 3 ~ 7
20
21 A10
22
23 ~ 25 A8, 9, 11
26 CE2
27
28 VCC
In/Out
In
Out
_
Out
_
In/Out
_
In/Out
_
_
In/Out
_
_
Out
In
Out
In/Out
NC _
In
In/Out
In
In/Out
CE In
In
OE In
In
In
WE In
In
— 17 —
Function
GND/0[V]
Common signal display
Not used
Segment signal for display
Not used
Clock terminal (DT-26S)
Not used
Main clock terminal (3.45MG)
Not used
Interrupt port
For data communication
Interrupt port
Not used
Turn on signal for Photo Sensor
Communication data through Photo Sensor
Turn on signal for LED (Infrared)
Function
No connect
Address bus
Data bus
GND / 0[V]
Data bus
Chip enable signal
Address bus
Output enable signal
Address bus
Chip enable signal
Write enable signal
Power supply / 3[V]