Casio Cassiopeia A-20, Service Manual & Parts List

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N o . Pin Name V o l t I o / O u t Function To/From
182 LOCK 3V I Not used
183 MEMCLB 3V I Not used
184 A25 3V I Address bus
185 A24 3V I Address bus
186 A23 3V I/O Address bus
187 A22 3V I/O Address bus
188 A21 3V I/O Address bus
189 A20 3V I/O Address bus
190 A19 3V I Address bus
191 A18 3V I Address bus
192 A17 3V I Address bus
193 A16 3V I Address bus
194 A15 3V I Address bus
195 A14 3V I Address bus
196 A13 3V I Address bus
197 A12 3V I Address bus
198 A11 3V I/O Address bus
199 A10 3V I/O Address bus
200 A9 3V I/O Address bus
201 A8 3V I/O Address bus
202 A7 3V I/O Address bus
203 VSS GND
204 A6 3V I/O Address bus
205 A5 3V I/O Address bus
206 A4 3V I/O Address bus
207 VDD2 3V +3V source
208 A3 3V I/O Address bus
209 A2 3V I/O Address bus
210 A1 3V I Address bus
211 A0 3V I Address bus
212 D0 3V I/O Data bus
213 D1 3V I/O Data bus
214 D2 3V I/O Data bus
215 D3 3V I/O Data bus
216 D4 3V I/O Data bus
217 D5 3V I/O Data bus
218 VDD2 3V +3V source
219 VSS GND
220 D6 3V I/O Data bus
221 D7 3V I/O Data bus
222 D8 3V I/O Data bus
223 D9 3V I/O Data bus
224 D10 3V I/O Data bus
225 D11 3V I/O Data bus
226 D12 3V I/O Data bus
227 D13 3V I/O Data bus
228 D14 3V I/O Data bus
229 D15 3V I/O Data bus
230 MCLOCK 3V I CKIO signal from CPU IC1
231 ONENB 3V O ON Circuit enable signal IC1
232 RXD0 3V O Data output of serial port 0 IC1
233 TXD0 3V I Data input of serial port 0 IC1
234 BREQB 3V O REQ signal to CPU IC1
235 RESETB 3V O RESET signal to CPU IC1
236 VSS GND
237 IRQB 3V O IRQ signal to CPU IC1
238 RXDSH 3V I/O Data output of signal port 1 IC5(RS232C),BGA288
239 TXDSH 3V I Data input of serial port 1 BGA288
240 SCK 3V O Clock of serial port 1 IC1
241 BACKB 3V I Bus access permission from CPU IC1
242 IOIS16B 3V O Write protect signal to CPU IC1