Casio JD-6500 Service Manual & Parts List page 18

Pin No. Signal
237 VDB
238, 239 VREG1, 4
240 ~ 243 VT1 ~ 4
244 VLCD
2. RAM (LC3564QM-85)
Pin No. Signal
1 NC
2 ~ 10 A0 ~ 7, 12
11 ~ 13 I/O 0 ~ 2
14 GND
15 ~ 19 I/O 3 ~ 7
20 CE
21 A10
22 OE
23 ~ 25 A8, 9, 11
26 CE2
27 WE
28 VCC
In/Out
In Low battery detection
4.4[V] < VDB < 5.2[V] ⇒ Low battery message
– VREG1: 2.6 [V]
VREG4: 5.0 [V]
– VT1 : 1.0[V]
VT3 : 2.0[V]
Out 5.9 [V]
In/Out
– No connect
In Address bus
In/Out Data bus
In GND / 0[V]
In/Out Data bus
In Chip enable signal
In Address bus
In Output enable signal
In Address bus
In Chip enable signal
In Write enable signal
In Power supply / 3[V]
— 16 —
Function
VT2 : 2.9[V]
VT4 : 3.9[V]
Function