Casio CFX-9850G PLUS Troubleshooting guide

R
MAY. 1997
CFX-9850G PLUS
(without price)
CFX-9850G PLUS(ZX-935A)

— 2 —
CONTENTS
1. SPECIFICATIONS ........................................................................................... 3
2. GENERAL GUIDE
2-1. Modes....................................................................................................... 4
2-2. Color Contrast Adjustment .................................................................... 5
2-3. Power Supply .......................................................................................... 6
3. RESET OPERATION....................................................................................... 9
4. DATA COMMUNICATIONS
4-1. Connecting Two Units .......................................................................... 10
4-2. Before Starting Data Communications ............................................... 10
4-3. Performing Data Transfer Operation................................................... 11
4-4. To Send the Screen .............................................................................. 14
4-5. Data Communication Precautions ...................................................... 15
5. OPERATION CHECK .................................................................................... 16
6. DATA TRANSFER CHECK........................................................................... 19
7. PIN FUNCTION.............................................................................................. 20
8. TROUBLESHOOTING................................................................................... 21
9. OPERATION PROBLEMS ............................................................................ 22
10. ERROR MESSAGE ....................................................................................... 23
11. SCHEMATIC DIAGRAMS ............................................................................. 25
12. PARTS LIST .................................................................................................. 28
13. EXPLODED VIEW ......................................................................................... 29

— 3 —
Variables: 28
Text display:
±1 ×10–99 to ±9.999999999 ×1099 and 0. Internal operations use 15-digit mantissa.
Exponential display range: Norm1: 10–2 > [x], [x] > 1010
Norm2: 10–9 > [x], [x] > 1010
Program capacity: 28 kbytes (max.)
Power supply:
Main: Four AAA-size batteries (LR03(AM4) or R03 (UM-4))
Back-up: One CR2032 lithium battery
Power consumption: 0.06 W
Battery life*:
Main:
LR03(AM4): Approximately 240 hours (continuous display of main menu)
Approximately 2 years (power off)
R03(UM-4): Approximately 150 hours (continuous display of main menu)
Approximately 2 years (power off)
Back-up: Approximately 2 years
* The batteries that have been installed in this unit when user purchased it had been used
in the factory test, so it will be impossible to fully satisfy this specifications when these
batteries are used.
Auto power off:
Power is automatically turned off approximately six minutes after last operation except when drawing dynamic
graphs.
The calculator automatically turns off if it is left for about 60 minutes with a calculation stopped by an output
command ( ), which is indicated by the “-Disp-” message on the display.
Ambient temperature range: 0 °C ~ 40 °C
Dimensions: 19.7 mm H ×83 mm W ×175.5 mm D (3/4" H ×3 1/4" W ×67/8" D)
Weight: 190 g (including batteries)
Current consumption:
TYP [µA] MAX [µA]
ON (MENU) 2416 2852
OFF 17.1
==
==
1. SPECIFICATIONS

— 4 —
Icon Mode Name Description
RUN Use this mode for arithmetic calculations and function calculations,
and for calculations involving binary, octal, decimal and hexadeci-
mal values.
STATistics Use this mode to perform single-variable (standard deviation) and
paired-variable (regression) statistical calculations, to perform tests,
to analyze data and to draw statistical graphs.
MATrix Use this mode for storing and editing matrices.
LIST Use this mode for storing and editing numeric data.
GRAPH Use this mode to store graph functions and to draw graphs using the
functions.
DYNAmic graph Use this mode to store graph functions and to draw multiple versions
of a graph by changing the values assigned to the variables in a
function.
2-1. Modes
• To select an icon
1. Press
MENU
to display the Main Menu.
2. Use the cursor keys ( , , , ) to move the highlighting to the icon you want.
3. Press
EXE
to display the initial screen of the mode whose icon you selected.
• You can also enter a mode without highlighting an icon in the Main Menu by inputting the number or letter
marked in the lower right corner of the icon.
• Use only the procedures described above to enter a mode. If you use any other procedure, you may end
up in a mode that is different than the one you thought you selected.
The following explains the meaning of each icon.
MENU
Currently selected icon
2. GENERAL GUIDE

— 5 —
Icon Mode Name Description
TABLE Use this mode to store functions, to generate a numeric table of
different solutions as the values assigned to variables in a function
change, and to draw graphs.
RECURsion Use this mode to store recursion formulas, to generate a numeric
table of different solutions as the values assigned to variables in a
function change, and to draw graphs.
CONICS Use this mode to draw graphs of implicit functions.
EQUAtion Use this mode to solve linear equations with two through six
unknowns, quadratic equations, and cubic equations.
PRoGraM Use this mode to store programs in the program area and to run
programs.
Time Value of Use thismodeto perform financial calculationsandto draw cashflow
Money and other types of graphs.
LINK Use this mode to transfer memory contents or back-up data to
another unit.
CONTrast Use this mode to adjust the color contrast of the display.
MEMory Use this mode to check how much memory is used and remaining,
to delete data from memory, and to initialize (reset) the calculator.
2-2. Color Contrast Adjustment
Adjust the color whenever objects on the display appear dim or difficult to see. There are two different settings
you can make to get color the way you want it.
• Color contrast
• Tint adjustment for each color
• To display the color adjustment screen
Highlight the CONT icon in the Main Menu and then press
EXE
.
•{INIT}/{IN•A} ... {initialize highlighted color}/{initialize all colors}
Use the following procedures while the color adjustment screen is on
the display to adjust the color contrast and tint settings.
COLOR
,,,
,,,
O B G
ORANGE
BLUE
GREEN
CONTRAST
INIT IN·A
– +

— 6 —
2-3. Power Supply
This unit is powered by four AAA-size (LR03(AM4) or R03(UM-4)) batteries. In addition, it uses a single
CR2032 lithium battery as a back up power supply for the memory.
If the following message appears on the display, immediately stop using the calculator and replace batteries.
If you try to continue using the calculator, it will automatically turn power off, in order to protect memory
contents. You will not be able to turn power back on until you replace batteries.
Be sure to replace the main batteries at least once every two years, no matter how much you use the calculator
during that time.
• To adjust the color contrast
1. Use the cursor and keys to move the pointer so it is next to CONTRAST.
2. Press the cursor key to make the display darker and the cursor key to make it lighter. Holding
down either key changes the setting at high speed.
• To adjust the color tint
1. Use the cursor and keys to move the pointer so it is next to the color (ORANGE, BLUE, GREEN)
whose tint you want to adjust.
2. Press the cursor key to givethecolor greener tint andthe cursor key to giveitan orange tint. Holding
down either key changes the setting at high speed.
• To exit the color adjustment screen
Press
MENU
to return to the Main Menu.
• It is recommended that you always adjust the CONTRAST setting first, and then adjust the tint settings
for individual colors.
• You can change the CONTRAST setting at any time without displaying the color adjustment screen.
Simply press
SHIFT
and then or to change the setting. Press
SHIFT
once again after get the display
looking the way you want.
Warning!
If you remove both the main power supply and the memory back up batteries at the same time, all memory
contents will be erased. If you do remove both batteries, correctly reload them and then perform the reset
operation.
Replacing Batteries
Precautions:
Incorrectly using batteries can cause them to burst or leak, possibly damaging the interior of the unit. Note the
following precautions:

— 7 —
• To replace the main power supply batteries
* Never remove the main power supply and the memory back up batteries from the unit at the same time.
* Never replace the main power supply battery compartment cover or turn the calculator on while the main
power supply batteries are removed from the calculator or not loaded correctly. Doing so can cause
memory data to be deleted and malfunction of the calculator. If mishandling of batteries causes such
problems, correctly load batteries and then perform the RESET operation to resume normal operation.
* Be sure to replace all four batteries with new ones.
1. Press
SHIFT OFF
to turn the calculator off.
Warning!
* Be sure to turn the unit off before replacing batteries. Replacing batteries with power on will cause data
in memory to be deleted.
2. Making sure that you do not accidently press the
AC/ON
key, slide the case onto the calculator and then turn
the calculator over.
3. Remove the back cover from the calculator by pressing it in the direction
indicated by arrow 1, and then sliding it in the direction indicated by arrow 2.
4. Remove the four old batteries.
5. Load a new set of four batteries, making sure that their positive +and negative
-ends are facing in the proper directions.
6. Replace the back cover.
7. Turn the calculator front side up and slide off its case. Next press
AC/ON
to turn on
power.
1
2
P
P
MAIN
• Be sure that the positive +and negative -poles of each battery are facing
in the proper directions.
• Never mix batteries of different types.
• Never mix old batteries and new ones.
• Never leave dead batteries in the battery compartment.
• Remove the batteries if you do not plan to use the unit for long periods.
• Never try to recharge the batteries supplied with the unit.
• Do not expose batteries to direct heat, let them become shorted, or try to
take them apart.
(Should a battery leak, clean out the battery compartment of the unit
immediately, taking care to avoid letting the battery fluid come into direct contact with your skin.)
Keep batteries out of the reach of small children. If swallowed, consult with a physician immediately.

— 8 —
• Power supplied by memory back up battery while the main power supply batteries are removed for
replacement retains memory contents.
• Do not leave the unit without main power supply batteries loaded for long periods. Doing so can cause
deletion of data stored in memory.
• If the figures on the display appear too light and hard to see after you turn on power, adjust the tint.
• To replace the memory back up battery
* Before replacing the memory back up battery, turn on the unit and check to see if the “Low battery!”
message appears on the display. If it does, replace the main power supply batteries before replacing the
back up power supply battery.
* Never remove the main power supply and the memory back up batteries from the unit at the same time.
* Be sure to replace the back up power supply battery at least once 2 years, regardless of how much you
use the unit during that time. Failure to do so can cause data in memory to be deleted.
1. Press
SHIFT OFF
to turn the calculator off.
Warning!
* Be sure to turn the unit off before replacing batteries. Replacing batteries with power on will cause data
in memory to be deleted.
2. Making sure that you do not accidently press the
AC/ON
key, slide the case onto the calculator and then turn
the calculator over.
3. Remove the back cover from the calculator by pressing it in the direction indicated
by arrow 1, and then sliding it in the direction indicated by arrow 2.
4. Remove screw Aon the back of the calculator, and remove the back up battery
compartment cover.
5. Remove the old battery.
6. Wipe off the surfaces of a new battery with a soft, dry cloth. Load it into the
calculator so that its positive +side is facing up.
7. Install the memory protection battery cover onto the calculator and secure it in
place with the screw. Next, replace the back cover.
8. Turn the calculator front side up and slide off its case. Next press
AC/ON
to turn on
power.
About the Auto Power Off Function
The calculator turns power off automatically if you do not perform any key operation
for about 6 minutes. To restore power, press
AC/ON
.
P
P
P
MAIN
MAIN
1
2
A

— 9 —
Warning!
The procedure described here clears all memory contents. Never perform this operation unless you want to
totally clear the memory of the calculator. If you need the data currently stored in memory, be sure to write
it down somewhere before performing the RESET operation.
• To reset the calculator
1. Highlight the MEM icon on the main menu and then press
EXE
, or press
tan
F.
2. Use to move the highlighting down to “RESET” and then press
EXE
.
3. Press F1 (YES) to reset the calculator or F6 (NO) to abort the operation without resetting anything.
4. Press
MENU
.
• If the display appears too dark or dim after you reset the calculator, adjust the tint.
• If the calculator stops operating correctly for some reason, use a thin, pointed
object to press the P button on the back of the calculator. This should make the
RESET screen appear on the display. Perform the procedure to complete the
RESET operation.
• Pressing the P button while an internal calculation is being performed will cause
all data in memory to be deleted.
F1 F6
P button
3. RESET OPERATION

— 10 —
4-1. Connecting Two Units
The following procedure describes how to connect two units with an optional SB-62 connecting cable for
transfer of programs between them.
To connect two units
1. Check to make sure that the power of both units is off.
2. Remove the covers from the connectors of the two units.
• Be sure you keep the connector covers in a safe place so you can replace them after you finish your data
communications.
3. Connect the two units using the SB-62 cable.
SB-62 cable
• Keep the connectors covered when you are not using them.
4-2. Before Starting Data Communications
In the Main Menu, select the LINK icon and enter the LINK Mode. The following data communication main
menu appears on the display. (Select the LINK icon, then press EXE button.)
Image Set:............Indicates the status of the graphic image send features.
Off: Graphic images not sent.
Monochrome: Pressing
F D
sends graphic images in monochrome.
Color: Pressing
F D
sends graphic images in color.
•{TRAN}/{RECV} ........ Menu of {send settings}/{receive settings}
•{IMGE} .........{menu of graphic image transfer settings}
Communications parameters are fixed at the following settings.
• Speed (BPS): 9600 bits per second
• Parity (PARITY): NONE
4. DATA COMMUNICATIONS

— 11 —
4-3. Performing Data Transfer Operation
Connect the two units and then perform the following procedures.
Receiving unit
To set up the calculator to receive data, press F2 (RECV) while the data communication Main Menu is
displayed.
The calculator enters a data receive standby mode and waits for data to arrive. Actual data receive starts as
soon as data is sent from the sending unit.
Sending unit
To set up the calculator to send data, press F1 (TRAN) while the data communication Main Menu is
displayed.
Press the function key that corresponds to the type of data you want to send.
•{SEL}.......{selects data items and sends them}
•{CRNT}....{selects data items from among previously selected data items and sends them}
•{BACK} ...{all memory contents, including mode settings}
• To send selected data items
Press
F1
(SEL) or
F2
(CRNT) to display a data item selection screen.
• {SEL} .......{selects data item where cursor is located}
• {TRAN}....{sends selected data items}
Use the and cursor keys to move the cursor to the data item you want to select and press F1 (SEL)
to select it. Currently selected data items are marked with “ ”. Pressing F6 (TRAN) sends all the selected
data items.
• To deselect a data item, move the cursor to it and press F1 (SEL) again.
Only items that contain data appear on the data item selection screen. If there are too many data items to fit
on a single screen, the list scrolls when you move the cursor to the bottom line of the items on the screen.
The following are the types of data items that can be sent.
▲
Data items

— 12 —
Data Item
Program
Mat n
List n
File n
Y=Data
G-Mem n
V-Win n
Picture n
DynaMem
Equation
Variable
F-Mem
Contents
Program contents
Matrix memory (A to Z) contents
List memory (1 to 6) contents
List file memory (1 to 6) contents
Graph expressions, graph write/non-write
status, View Window contents, zoom factors
Graph memory (1 to 6) contents
View Window memory contents
Picture (graph) memory (1 to 6) data
Dynamic Graph functions
Equation calculation coefficient values
Variable assignments
Function memory (1 to 6) contents
Overwrite
Check*1
Yes
Yes
Yes
Yes
No
Yes
No
No
Yes
No
No
No
Password
Check*2
Yes
• {SYBL} ....{symbol input}
After inputting the password, press
EXE
.
• {YES} ......{replaces the receiving unit's existing data with the new data}
• {NO} ........{skips to next data item}
*2With password check: If a file is password protected, a message appears asking for input of the
password.
Data item name
*1No overwrite check: If the receiving unit already contains the same type of data, the existing data is
overwritten with the new data.
With overwrite check:If the receiving unit already contains the same type of data, a message appears
to ask if the existing data should be overwritten with the new data.
Name of password protected file
Password input field

— 13 —
• To execute a send operation
After selecting the data items to send, press F6 (TRAN). A message appears to confirm that you want to
execute the send operation.
• {YES}.....{sends data}
• {NO}.......{returns to data selection screen}
Press F1 (YES) to send the data.
• You can interrupt a data operation at any time by pressing AC .
• To send backup data
This operation allows you to send all memory contents, including mode settings. While the send data type
selection menu is on the screen, press F6 (BACK), and the back up send menu shown below appears.
Press F6 (TRAN) to start the send operation.
Press AC to return to the data communication Main Menu.
Sending Unit Receiving Unit
The following shows what the displays of the sending and receiving units look like after the data communication
operation is complete.

— 14 —
Sending Unit Receiving Unit
The following shows what the displays of the sending and receiving units look like after the data communication
operation is complete.
Press AC to return to the data communication Main Menu.
• Data can become corrupted, necessitating a RESET of the receiving unit, should the connecting cable
become disconnected during data transfer. Make sure that the cable is securely connected to both units
before performing any data communication operation.
4-4. To Send the Screen
The following procedure sends a bit mapped screen shot of the display to a connected computer.
1. Connect the unit to a personal computer or to a CASIO Label Printer.
2. In the data communication main menu, press F6 (IMGE), and the following display appears.
• {OFF} .......{graphic images not sent}
• {MONO}/{COLR}.....{monochrome}/{color} bitmap
3. Press a function key to specify either “Monochrome” or “Color” for the Image Set Mode.
4. Display the screen you want to send.
5. Set up the personal computer or Label Printer to receive data. When the other unit is ready to receive,
press
F D
to start the second operation.
• Selecting “Monochrome” for Image Set allows data to be sent to any CASIO Label Printer equipped with
data communications capabilities.
Selecting “Color” allows data to be sent to Color Label Printer models only.
You cannot send the following types of screens to a computer.
• The screen that appears while a data communication operation is in progress.
• A screen that appears while a calculation is in progress.
• The screen that appears following the reset operation.
• The low battery message.
• The flashing cursor is not included in the screen image that is sent from the unit.
• If you send a screen shot of any of the screens that appear during the data send operation, you will not
be able to then use the sent screen to proceed with the data send operation. You must exit the data send
operation that produced the screen you sent and restart the send operation before you can send
additional data.
• You cannot use 6 mm wide tape to print a screen shot of a graph.

— 15 —
4-5. Data Communication Precautions
Note the following precautions whenever you perform data communications.
• An error occurs whenever you try to send data to a receiving unit that is not yet standing by to receive data.
When this happens, press
AC
to clear the error and try again,after setting up the receiving unit to receive
data.
• An error occurs whenever the receiving unit does not receive any data approximately six minutes after it
is set up to receive data. When this happens, press
AC
to clear the error.
• An error occurs during data communications if the cable becomes disconnected, if the parameters of the
two units do not match, or if any other communications problem occurs. When this happens, press AC to
clear the error and correct the problem before trying data communications again. If data communications
are interrupted by AC key operation or an error, any data successfully received up the interruption will be
in the memory of the receiving unit.
• An error occurs if the receiving unit memory becomes full during data communications. When this happens,
press AC to clear the error and delete unneeded data from the receiving unit to make room for the new
data, and then try again.
• To send picture (graph) memory data, the receiving unit need 1-kbyte of memory for use as a work area
in addition to the data being received.

— 16 —
DISPLAY
OFF (No display)
Frame is displayed
No color, no display
All orange dots are displayed
All green dots are displayed
All blue dots are displayed
Checkers are displayed
Reverse checkers are diaplayed
ZX935 Ver.X TEST MODE
1. Cnt
2. LCD
3. KEY
4. DET
5. TRS
6. ROM
7. RAM
8. CYC
0. Rst
✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽
✽
✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽
✽
MEMORY CLEARED!
PRESS [MENU] KEY
✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽
✽
✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽
✽
RESET
RESET ALL MEMORIES?
RESET ALLYES NO
[F1] [F6]
OPERATION
Press Pbutton on the back of
the unit using any thin and pointed
object.
Press
F1
button.
Press
SHIFT
, then
AC/ON
button.
Press
AC/ON
button while press-
ing
F6
and
ab/c
buttons.
Press 1, then
EXE
button.
Press
EXIT
button.
Press 2button.
Press
EXE
button.
Press
EXE
button.
Press
EXE
button.
Press
EXE
button.
Press
EXE
button.
Press
EXE
button.
NOTE
Reset
TEST mode menu
The contrast is
changed automati-
cally.
Min→Max→default
TEST mode menu
Check for display
Check for display
Check for display
Check for display
Check for display
STEP
1
2
3
4
5
6
7
8
9
10
11
12
13
+–
ORANGE
BLUE
GREEN
CONTRAST
COLOR
,,,,,
,,,,,
,,,,,
,,,,,
O B G
INIT IN•A
ZX935 Ver.X TEST MODE
1. Cnt
2. LCD
3. KEY
4. DET
5. TRS
6. ROM
7. RAM
8. CYC
0. Rst
❋Performing this operation check, the data stored in this calculator deleted. If you want not to delete these
data, save these data to another CFX-9850G PLUS.
5. OPERATION CHECK

— 17 —
DISPLAY
Trace
Zoom, V-Window, Sketch
ROMSIZE 8M bits
ROM OK
checksum= xxxxxxxx
RAMSIZE 32K byte
RAM OK
RAMaddress 7FFF
RAMwrite AA
RAMread AA
Blue
No color
Orange
Green
NOTE
Check four colors.
If the colors do not
appear accurately,
perform the adjust-
ment mentioned in
page 5.
Check four colors
TEST mode menu
Check for keys
Check for keys.
To push the key
sequentially that is
being appeared in
the display.
TEST mode menu
ROM check
TEST mode menu
RAM check
OPERATION
Press
EXE
button.
Press
EXE
button.
Press
EXE
button.
Press 3button.
Press F1 F2
F3
..... buttons.
Press .....
EXE
buttons.
Press 6button.
Press
EXE
button.
Press 7button.
STEP
14
15
16
17
18
19
20
21
22
ZX935 Ver.X TEST MODE
1. Cnt
2. LCD
3. KEY
4. DET
5. TRS
6. ROM
7. RAM
8. CYC
0. Rst
ZX935 Ver.X TEST MODE
1. Cnt
2. LCD
3. KEY
4. DET
5. TRS
6. ROM
7. RAM
8. CYC
0. Rst
ZX935 Ver.X TEST MODE
1. Cnt
2. LCD
3. KEY
4. DET
5. TRS
6. ROM
7. RAM
8. CYC
0. Rst
Blue
No color
Orange
Green

— 18 —
OPERATION
Press
EXE
button.
Press
SHIFT
, then
AC/ON
button.
DISPLAY
OFF (No display)
NOTE
Reset
End
STEP
23
24
✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽
✽
✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽✽
✽
MEMORY CLEARED!
PRESS [MENU] KEY

— 19 —
NOTE
TEST mode
menu
Check for
sending and
receptivity
Check for
sending and
receptivity
TEST mode
menu
End
Press
AC/ON
button
while pressing
F6
and
ab/c
but-
tons.
Press
5
button.
Press
1
button.
Press 2button.
Press
EXE
button.
Press
1
button.
Press
EXE
button.
Press
AC/ON
button.
Take the steps as
same as the end of
5. OPERATION
CHECK to end this
check.
Press
AC/ON
button
while pressing
F6
and
ab/c
but-
tons.
Press 5button.
Press 1button.
Press 1button.
Press
EXE
button.
Press 2button.
Press
EXE
button.
Press
AC/ON
button.
Take the steps as
same as the end of
5. OPERATION
CHECK to end this
check.
Turn off both units (Aand Bunit), then connect them using the cable SB-60 or SB-62. Perform STEP 1 ~ 4
described in 5. OPERATION CHECK before this check.
STEP
STEP 4
of
5.OP-
ERA-
TION
CHECK
1
2
3
4
5
6
7
8
9
10
OPERATION DISPLAY
A unit B unit DISPLAY
TRANSMIT Check
1. COM Check
2. VCCI Spec Test
0. Self
1. Send
2. Receive
WAITING
RECEIVING
COM OK
0. Self
1. Send
2. Receive
SENDING
COM END
0. Self
1. Send
2. Receive
TRANSMIT Check
1. COM Check
2. VCCI Spec Test
0. Self
1. Send
2. Receive
SENDING
COM END
0. Self
1. Send
2. Receive
WAITING
RECEIVING
COM OK
0. Self
1. Send
2. Receive
OPERATION
ZX935 TEST MODE
1. Cnt
2. LCD
3. KEY
4. DET
5. TRS
6. ROM
7. RAM
8. CYC
0. Rst
ZX935 TEST MODE
1. Cnt
2. LCD
3. KEY
4. DET
5. TRS
6. ROM
7. RAM
8. CYC
0. Rst
ZX935 TEST MODE
1. Cnt
2. LCD
3. KEY
4. DET
5. TRS
6. ROM
7. RAM
8. CYC
0. Rst
ZX935 TEST MODE
1. Cnt
2. LCD
3. KEY
4. DET
5. TRS
6. ROM
7. RAM
8. CYC
0. Rst
6. DATA TRANSFER CHECK

— 20 —
Pin No. Pin Name Input/Output Function
1 ~ 14 KO14 ~ KO1 O Key common signal
15 ~ 22 KI8 ~ KI1 I Key input signal
23 BUFON O Chip select for RAM
24 IT2 I Interrupt input
25 IT0 I Interrupt input
26 ~ 46 AO20 ~ AO0 O Address bus
47 ~ 54 IO0 ~ IO7 I / O Data bus
55 OEBO O Output enable signal for RAM
56 WEBO O Write enable signal for RAM
64 CS3BO O Chip selecting signals
69 ~ 72 OPT3 ~ OPT0 O Changeover signal
73 PORT7 I Receiving terminal for data communication
74 PORT6 I Receiving terminal for data communication
75 PORT5 O Transmitting terminal for data communication
76 PORT4 O Transmitting terminal for data communication
80 PORT0 I Low battery message for back-up battery (2.6 V)
81 VSS I GND
82 PI I 4.3 MHz clock input
83 PO O 4.3 MHz clock output
84 VDD I +6 V source
85 XO O Clock output
86 XI I Clock input
87 VCC I +6 V source
88 VREG2 O Voltage for main switch detection
89, 90 TS1, TS2 — Test terminals of factory purpose only
91 VSSR I GND
94 VSS I GND
96 ITOFF I Switching terminal from main switch
97 TEMU — Test terminals of factory purpose only
98 SW I Receiving terminal for reset switch
99 VDB I +3 V source
100 VREG1 — Test terminals of factory purpose only
101 VREG4 O +3 V source for ROM
102 VREG5 — Test terminals of factory purpose only
103 VDT1I I Forced power off detecting terminal (2.3 V)
104 VDT2I I Low battery message for main battery (2.5 V)
105 VREG3 — +3 V source for RAM
CPU HCD62121A03 (HC-3017) : COB
NOTE: The CPU is bonding on the PCB. If the CPU is defective, replace the PCB ass'y because
the CPU cannot be replaced.
7. PIN FUNCTION