Casio CE-6800 User manual

SERVICE MANUAL
ELECTRONIC CASH REGISTER
(without price)
CE-6800(EX-475EP)
MAY. 2001
Printer Model : M-U420B-031
INDEX

CONTENTS
CE-6800 Page
1. SPECIFICATIONS........................................................................................ 1
2. BLOCK DIAGRAM....................................................................................... 3
3. TO OPEN THE UPPER CASE ..................................................................... 5
4. CIRCUIT EXPLANATION ............................................................................ 7
4-1. Power supply circuit ................................................................................................. 7
4-2. Reset and power down circuit.................................................................................. 8
4-3. CPU description......................................................................................................... 8
4-4. Momory chip selection circuit................................................................................ 11
4-5. Flash ROM1 address circuit ................................................................................... 12
4-6. Memory map ............................................................................................................ 12
4-7. Printer drive circuit.................................................................................................. 13
4-8. RS232C port COM1 circuit...................................................................................... 14
4-9. RS232C port COM2 and COM3 circuit ................................................................... 15
4-10. To mount optional circuit ....................................................................................... 16
5. DIAGNOSTIC OPERATION....................................................................... 17
5-1. To start the diagnostic program ............................................................................ 17
5-2. Check item ............................................................................................................... 17
5-3. Operation of each test............................................................................................. 17
5-4. Switch status test .................................................................................................... 18
5-5. Individual function test ........................................................................................... 19
5-6. To exit the diagnostic mode ................................................................................... 27
6. IC DATA ..................................................................................................... 28
7. PCB LAYOUT ............................................................................................ 38
8. CIRCUIT DIAGRAM ................................................................................... 40
9. PARTS LIST............................................................................................... 56

— 1 —
• CPU Name uPD784215GC201-8EU
Number of control bit 8bit
Internal RAM 4 KBytes
• RAM1 and 2 Name HY628100ALLG-70
Capacity 1 Mbits
• Option RAM3 and 4 Name HM628512BLP-5/7SCL
Capacity 512 Kbytes
• Flash ROM Name LH28F016SCT-L95
Capacity 16 M bits
• Printer Name M-U420-031
Print method Impact dot matrix printer
Paper cut Manual paper cut
• Roll paper Type Fine-quality paper
Size Width 44.5 ±0.5 mm
Roll diam 83 mm or less
Thickness 75 ±15 µm
1-2. Environmental specifications
• Operating temperature 0 °C ~ 40 °C
• Operating humidity 10 % ~ 90 %
• Storage temperature -25 °C ~ 65 °C
• Storage humidity 10 % ~ 95 %
• Vibration strength 1.5 G (The machine must be in the carton box)
1-3. Main components
1. SPECIFICATIONS (CE-6800)
1-1. Electrical specifications
110V
• Power consumption In operation Max. 0.7 A
Min. 0.3 A
Power OFF 0.3 A
• Memory protection Back-up battery VL3032/1F2
Back-up period 90 days (25 °C)
Battery life Replace the battery every 5 years.
Recharge time 48 hours
• Clock & Calendar Accuracy Within ±30 sec. per month (25 °C)
Auto calendar Effective until 2099 A.D.

— 2 —
1-5. Option List
1-4. Drawer List
DRAWER NAME Specification NOTE
• DL-2771 D-9A2C-B84-9*
DEVICE NAME MODEL NOTE
• RAM CHIP RAM-610-10LL Capacity 4Mbits (512 Kbytes)
• Wet cover WT-77
• Modem Sports star Recommend model : U.S.Robotics
56.4Kbps Com 1 port only
• P/C cable PRL-CB-2 Com 1 port only
• Handy scanner HHS-15 Com 2 port only
• Fixed scanner HS1250 Com 2 port only (PSC model)
• Laser scanner Quick Scan 6000 Com 2 port only (PSC model)
• Slip printer SP-1300 Connect to Com 2 or 3.
It is possible to drive only one printer.
• External printer UP-350 Connect to Com 1,2 or 3.
It is possible to drive until 2 printers.
• External printer UP-250 Connect to Com 1,2 or 3.
It is possible to drive until 2 printers.
• Scale Model 6710 Com 3 only (NCI model)
• Slip printer cable PRT-CB-8C Connect Com 2 or 3. (Cable lngth 1.5m)
• External printer cable PRT-CB-8A Connect to Com 1,2 or 3. (Cable length 3 m)
• External printer cable PRT-CB-8B Connect to Com 1,2 or 3. (Cable length 5 m)
• Power unit PS-170 Epson model
for External printer
• Power cord AC-170 Epson model
for power unit
• Power-board JDC model
• Molti-drow kit MDL-10
• ARCNET board IO-PB-14 In-line communication board
CAUTION
Danger of explosion if battery is incorrectly
replaced.
Replace only with the same or equivalent type
recommended by the manufacturer.
Dispose of used batteries according
to the manufacture’s instructions.

— 3 —
2. BLOCK DIAGRAM
2-1. PCB CONNECTION

— 4 —
2-2. BLOCK DIAGRAM (CE-6800)
Address
Latch
Address bus A8 - A19
A0 -A7
Data bus D0 -D7
CPU
uPD784215GC201-8EU
Data buffer
I/O selector
Printer driver
Printer
M-U420-031
COM1
COM3 Driver
Driver
Display driver and Key control circuit
Main display
(Dot & segment) Customer
display Keyboard
ARCNET
driver
IN-Line
MAIN PCB E457-1 C
RAM1
HY628100A
LLG-70
(128 K bytes)
RAM3
(Option)
HM628512ALP-7
512 K bytes
(RAM-610)
Flash ROM 1
LH28F016SCT-L95
(2 M bytes)
RAM2
HY628100A
LLG-70
(128 K bytes)
Option I/O PB14
RAM4
(Option)
HM628512ALP-7
512 K bytes
(RAM-610)
COM2

— 5 —
3. TO OPEN THE UPPER CASE
1. Open the printer cover. Then, remove the ribbon
cover from the machine.
2. Remove the 2 screws of the upper case.
3. Push the 3 dots marking point at the right side of
lowercase.Atthesametime,slidetheuppercase
to the front side.
4. Open upper cese from the left side.
Open the printer cover.
Remove the ribbon cover.
Remove the 2 screws.
Slide the upper case
to the front side.
Power switch cover
Press the 3 dots marking point.

— 6 —
6. To remove the Main PCB, release the 3 locking supporters of point A and the COM1 port outside screws.
5. The each parts of the Main PCB are located as shown in the picture.
7. Power supply unit cover is removed by 3 screws. And, the 3 Fuses are located as shown in the picture.
Battery
Flash ROM 1 (2 Mbytes)
Main PCB
RAM 1 (128 Kbytes)
RAM 4
Option
RAM 3
Option
COM 1 port
CPU
Buzzer
Printer cable
Display cable
Power supply connector
Reset Switch
Keyboard select switch
Remove 2 screws for COM 1 port.
Point A
Release 3 locking
suppeares.
Main PCB
Remove the 3 screws.
Then, remove the power supply cover.
Power transformer
Fuse F1
250V 1A
Fuse F2
250V 2A
Fuse F3
250V 400mA
(Not used for CE-6000)

— 7 —
4. CIRCUIT EXPLANATION
4-1. Power supply circuit
The power supply circuit provides the following voltage for the main circuit.
Output Pin No1----- VC1 (DC32.3V): To the VC line for the VFD Display power. (Not used for CE-6000)
Output Pin No.2---- VC2 (DC24V): To the Vp line for the printer power.
Output Pin No.3---- VLED (DC5.85V): To the Vcc,Vcc2 and Vdd for the logic circuit power.
Output Pin No.4---- GND: Signal GND.
The power switch SW1 is located at the right side of the lowercase.
After connected the power plug into AC outlet and turn on the SW1, the transformer T1 will genarate the
about AC33V to secondary side. Then, after rectifier circut, the VC1 (DC32.3V) is supplied to the VC line
for display power (for the drive of display tube. Not for LED model.)
The IC2 is the shunt regulator for the control of Q1 transistor. This circuit is genarate the VC2 (DC24V)
for the printer power. The IC1 is regulator for 5V power supply.
Power supply PCB E445-S1
Power SW1 cover
Power switch SW1

— 8 —
4-2. Reset and powe down circuit
The rest and power down circuit are as following circuit. The reset switch is provided for the hard reset
to cleare the system error. Use this switch only when the FMAC or MAC are not possible to perform.
Reset switch
The position of Reset switch
From top of view From rear of view
4-3. CPU pin description(uPD784215GC201-8EU)
The CPU pin descriptions are as follows:
Reset switch
Printer
The mark of reset switch

— 9 —
CPU pin description(uPD784215GC201-8EU)
Pin No. Signal Name Description In/Out
1 P120 HD1 HEAD PIN DRIVE HD1 Out
2 P121 HD2 HEAD PIN DRIVE HD2 Out
3 P122 HD3 HEAD PIN DRIVE HD3 Out
4 P123 HD4 HEAD PIN DRIVE HD4 Out
5 P124 HD5 HEAD PIN DRIVE HD5 Out
6 P125 HD6 HEAD PIN DRIVE HD6 Out
7 P126 HD7 HEAD PIN DRIVE HD7 Out
8 P127 HDGATE2 HEAD GATE2 Out
9 VDD VDD Power supply VDD +5V
10 X2 X2 Clock 12.5 MHz In
11 X1 X1 Clock 12.5 MHz In
12 VSS GND Power supply GND
13 XT2 XT2 Clock In
14 XT1 XT1 Clock In
15 RESET RESET Reset termial In
16 P00 TP Timing puls from printer TP In
17 P01 COM2 SEL COM 2 selection Out
18 P02 CUTTER RP Auto-cutter reset pulse CUTTER RP In
19 P03 PWD Power down signal In
20 P04 VFD BUSY Display controller busy signal In
21 P05 RP Reset pulse from printer RP In
22 P06 IRQ ARCNET Interrupt rquest form ARCNET controller In
23 AVDD VDD Power supply VDD +5V
24 AVREF0 AVREF0 Connected to VDD +5V
25 P10 AVREF Vp voltage check terminal In
26 P11 HDTH Head thermistor input In
27 P12 CROM IN Flash ROM cassette in signal In
28 P13 DWS Drawer sensor input In
29 P14 DSR1 COM1 DSR signal In
30 P15 CI1 COM1 CI signal In
31 P16 CD1 COM1 CD signal In
32 P17 P.N.E. Paper near end sensor input In
33 AVSS GND Power supply GND
34 P130 LED SLATCH LED Latch signal Out
35 P131 LED CE LED chip enable signal Out
36 AVREF1 VDD Connected to VDD +5V
37 P70 RX2 COM2 and COM3 receive data In
38 P71 TX2 COM2 and COM3 transmit data Out
39 P72 RAM ENABLE RAM enable signal Out
40 P20 RX1 COM1 receive data In
41 P21 TX1 COM1 transmit data Out
42 P22 RTS1 COM1 RTS signal Out
43 P23 MOTOR Motor drive signal Out
44 P24 RTS2 COM2 RTS signal Out
45 P25 LED SIN LED data in signal In
46 P26 LED SOUT LED data out signal Out
47 P27 LED SCK LED SCK signal out Out
48 P80 RB0/CB0 Bank selection RB0/CB0 Out
49 P81 RB1 Bank selection RB1 Out
50 P82 RB2 Bank selection RB2 Out

— 10 —
Pin No. Signal Name Description In/Out
51 P83 RB3 Bank selection RB3 Out
52 P84 RB4/CB1 Bank selection RB4/CB1 Out
53 P85 FB0/CB2 Bank selection FB0/CB2 Out
54 P86 FB1 Bank selection FB1 Out
55 P87 FB2 Connected to GND
56 P40 D0 Data/address bus D0/A0 In/Out
57 P41 D1 Data/address bus D1/A1 In/Out
58 P42 D2 Data/address bus D2/A2 In/Out
59 P43 D3 Data/address bus D3/A3 In/Out
60 P44 D4 Data/address bus D4/A4 In/Out
61 P45 D5 Data/address bus D5/A5 In/Out
62 P46 D6 Data/address bus D6/A6 In/Out
63 P47 D7 Data/address bus D7/A7 In/Out
64 P50 A8 Address bus A8 Out
65 P51 A9 Address bus A9 Out
66 P52 A10 Address bus A10 Out
67 P53 A11 Address bus A11 Out
68 P54 A12 Address bus A12 Out
69 P55 A13 Address bus A13 Out
70 P56 A14 Address bus A14 Out
71 P57 A15 Address bus A15 Out
72 VSS GND Power supply GND
73 P60 A16 Address bus A16 Out
74 P61 A17 Address bus A17 Out
75 P62 A18 Address bus A18 Out
76 P63 A19 Address bus A19 Out
77 P64 RD Read signal Out
78 P65 WR Write signal Out
79 P66 WAIT Wait signal In
80 P67 ASTB Address strobe signal Out
81 VDD VDD Power supply VDD +5V
82 P100 BUZZER Buzzer output signal Out
83 P101 R.FEED Receipt paper feed signal Out
84 P102 J.FEED Journal paper feed signal Out
85 P103 STAMP Stamp signal Out
86 P30 HDGATE1 Head gate 1 signal Out
87 P31 FLASH RST Flash reset signal Out
88 P32 DTR1 COM1 DTR signal Out
89 P33 CTS1 COM1 CTS signal In
90 P34 DTR2 COM2 DTR signal Out
91 P35 HDPLS Head pulse signal In
92 P36 DW1 Drawer signal 1 Out
93 P37 DW2 Drawer signal 2 Out
94 TEST GND Connected to GND
95 P90 MODE SIN Mode switch data in signal In
96 P91 MODE SCK Mode switch SCK signal Out
97 P92 MODE SLOAD Mode switch data load signal Out
98 P93 KI SLOAD Key data load signal Out
99 P94 HD8 HEAD PIN DRIVE HD8 Out
100 P95 HD9 HEAD PIN DRIVE HD9 Out

— 11 —
RB1
RB2
RB3
RB4/CB1
FB1
RAM enable
ARC RESET
RAM1 CE
RAM4 CE
RAM2 CE
RAM3 CE
RAM1 CE is for RAM 1 chip
enable signal.
RAM1 selection
The RAM1 is selected by the RAM enable signal "H" and the 2CS signal " L" of output pin No.13 . The
2SC signal becomes "L" when the CPU address is as follows:
A19 A18 A17 A16 A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
LLHLXXXXXXXXXXXXXXXX
2XXXX
Also, the 3SC signal becomes "L" when the CPU address is as follows:
A19 A18 A17 A16 A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
LLHHXXXXXXXXXXXXXXXX
3XXXX
Therefore, the RAM1 CE will active when the CPU adress is from 20000H to 3FFFFH with RAM enable
signal "H".
Flash ROM1 selection
The Flash 1 CE will active by the IC25 output pin No.3. This is inverted signal of A19.
A19 A18 A17 A16 A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
HLLLXXXXXXXXXXXXXXXX
8XXXX
Therefore, the Flash1 CE will active when the CPU adress is from 80000H to FFFFFH.
4-4. Memory chip selection circuit
The RAM chip select signals made by the following circuit.
There are 4 chip enable signal lines for RAM selection and 3 chip enable signal lines for Flash ROM
selection (including Memory cassette).

— 12 —
4-5. Flash ROM1 address circuit
The Flash ROM1 address signals FA17 to FA20 are made by the following circuit.
The Flash ROM1 (LH28F016SCT-L95, 16M bits) is used for the application program.
4-6. Memory map
The memory table is as follows:
RAM enable 2CS 3CS 4CS 8CS CCS A18 A19 RAM BANK Flash BANK RAM1 Flash1
No. RB0 RB1 RB2 RB3 RB4 FB0 FB1 FB2 CS A16 CS A18
H LHHHHLLCOMXXXXXXXXLLHX
H HLHHHLLCOMXXXXXXXXLHHX
H HHLHHHL 0L HL L XXXXHXHX
1HHL L XXXXHXHX
H HHLHHHL L L HL XXXXHXHX
HL HL XXXXHXHX
H HHLHHHL L HHL XXXXHXHX
HHHLXXXXHXHX
H HHLHHHL 2LLLHLXXXHXHX
3HL L HL XXXHXHX
4L HL HL XXXHXHX
5HHL HL XXXHXHX
6L L HHL XXXHXHX
7HL HHL XXXHXHX
8LHHHLXXXHXHX
9HHHHLXXXHXHX
10L L L HHXXXHXHX
11HL L HHXXXHXHX
12L HL HHXXXHXHX
13HHL HHXXXHXHX
14L L HHHXXXHXHX
15HL HHHXXXHXHX
16LHHHHXXXHXHX
17HHHHHXXXHXHX
L XXXXXXX XXXXXXXXHXXX
X HHLHHHL HLLLXLHLHXHX
HLLLXHHLHXHX
X HHLHHHL LLLLLLLLHXHX
HLLLLLLLHXHX
LLLLHLLLHXHX
HLLLHLLLHXHX
LLLLLHLLHXHX
HLLLLHLLHXHX
LLLLHHLLHXHX
HLLLHHLLHXHX
X HHLHHHL XLLLXLXHHXHX
XLLLXHXHHXHX
X HHHLHLH XXXXXLXHHXHX
XXXXXHXHHXHX
H HHHLHLH XXXXXXXLHXLA18
H HHHHL HH XXXXXXXXHXLA18
Flash ROM1 (16M bits)
CPU address BANK port Flash memory address NOTE
A19 A18 A17 FC2 FC1 FC0 BANK FA20 FA19 FA18 FA17 Memory block No. 8M bank 16M bank
H L L L L L 0 L L A18 A17 02 to 07
L H L L H 1 L H A18 A17 0A to 0F
H L H X X 2 A18 A17 L L 08,09
10,11,18,19
L H L 3 H L A18 A17 12 to 17
L H H 4 H H A18 A17 1A to 1F
H H H X X X Common LLLL00,01 Common

— 13 —
Memory map
4-7. Printer drive circuit
The printer drive circuit is as follows:
IC5 (MTA001M-F4101) is the head pin driver IC. And, the Transistors Q6,Q7 and Q8 are the motor drive
circuit. The IC1 (TA8429H) is the auto paper cut driver circuit.
00000h CPU internal memory
Mask ROM 128K
RAM 5K
0FFD0h External I/O Mapping 16bytes
0FFE0h
20000h RAM1 128 K bytes
40000h
Not used
80000h
Bank area
Flash 1 384 K bytes 16 M bit
(for
A0000h Application 8 M bit
program area) 4 M bit
2 M bytes Bank0 Bank1 Bank2 Bank3 Bank4
00,01 08,09 14,15 20,21 26,27 Block No.
(07,06) (0F,0E) (19,18) (17,16) (1F,1E) (Memory Block)
C0000h
02,03 10,11 16,17 22,23 28,29
(05,04) (0D,0C) (11,10) (15,14) (1D,1C)
E0000h 04,05 12,13 18,19 24,25 30,31
Common area (o3,02) (0B,0A) (09,08) (13,12) (1B,1A)
128 K bytes
Block
06,07
FFFFFh (00,01)

— 14 —
4-8. RS232C port COM1 circuit
The COM1 circuit is as follows:
The COM1 port pin location is as shown below:
1
6 7 8 9
2 3 4 5
Signal
CD
RxD
TxD
DTR
GND
DSR
RTS
CTS
CI
1
2
3
4
5
6
7
8
9
Pin

— 15 —
4-9. RS232C port COM2 and COM3 circuit
The circuits of COM2 and COM3 are as follows:
TP48
The COM2, and COM3 port pin locations are as shown below:
COM2 COM3
COM2 port COM3 port
1
6 7 8 9
2 3 4 5
Signal
NC
RxD
TxD
DTR
GND
DSR
RTS
CTS
NC
1
2
3
4
5
6
7
8
9
Pin
Signal
NC
RxD
TxD
DTR
GND
DSR
RTS
CTS
VCC (+5V)
1
2
3
4
5
6
7
8
9
Pin

— 16 —
1-4. Openthebackcoveroflowercabe toreleasethe2screws. Then,connectthenecessaryextension
cablefordrawer. Inthiscase,donoforgettofixtheFGwireoftheextensioncabletotheframeground
by the screw.
1-5. Connect 1 pin FG connector of the drawer extension cable to the drawer 1 pin connector.
Close the back cover of lower case by 2 screws.
4-10. To mount optional circuit
The following optional circuits are provided for this model CE6800.
1. Multi-drawer circuit
2. Paper near end circuit
1) Multi-drawer kit (Only Drawer 2)
1-1. Preparethefollowingpartskitformulti-drawercircuit.Thepartskitsaresuppliedfromsalesdivision.
MDL-10 ------------- Multi-drawer kit
1-2. Check whether the parts of multi-drawer kit are as follows:
1-3. Connect the drawer connector cable to the main PCB by solder.
Code No. Parts Name Specification Q'ty
10006121 Drawer connector cable E440721A*1 1
62481534 Extension cable for Drawer E440714*1 1
59000209 Screw 3X4ZMC-3. 1
Drawer2 Drawer3 Drawer4
Red
Brown
Black
Release the 2 screws and open the
back cover of lower case. Connect the extension drawer cable to the
drawer connector.
Fix the FG wire of the
extension drawer cable by
screw of the parts kit.

— 17 —
5. DIAGNOSTIC OPERATION
5-1. To start the diagnostic program
1. Plug the power cord into an AC outlet.
2. Set the mode switch to "OFF" position.
3. While pressing the "Jounal feed " button,
turn the mode switch to "PRG" position.
4. Release the "Journal feed" button.
5. Input "99990000" and press "ST" ("#2" key).
6. Diagnostic program is executed.
5-2. Check item
The following test can be checked in the diagnostic test.
1. Key code test
2. Switch status test
3. Individul function test
5-3. Operation of each test
1. Key code test
When pressing a key, the machine displays
the following key code.
HARD KEY CODE TABLE
Hard key code
DISPLAY
Note: "014" button is work for "#2" key. "013" button is work for "#1" key.
XXX zz
Key borad information
11: Stroke Key
10: Stroke + Flat Key
01: Full Flat Key
089 090 091 092 093 094
095 096 097 098 099 100
RF JF 077 070 068 066 066 060 054 048 042 036 030 024 018
087 082 076 069 067 065 065 059 053 047 041 035 029 023 017
086 081 075 789064 058 052 046 040 034 028 022 015
085 080 074 456063 057 051 045 039 033 027 014 016
084 079 073 123062 056 050 044 038 032 026 020 021
083 078 072 011 12 061 055 049 043 037 031 025 019 013

— 18 —
5-4. Switch status test
Press "C" button or changing the switch condition,the switch status is appeared on the transaction place of the
display. The clerk key switch condition is showen at the 6 and 7 digit number's place of display. For the clerk
button model, the pressed LED will light on.
[DISPLAY]
Printer connection sensor
Off : Connected
ON : Not connected
Journal head sensor
Off : Head down
ON : Head up
Receipt head sensor
Off : Head down
ON : Head up
Journal paper sensor
Off : Paper in
ON : Paper out
Receipt paper sensor
Off : Paper in
ON : Paper out
Mode switch status
0 : No connetion
1 : PGM
2 : RF
3 : REG1
4 : REG2
5 : X
6 : Z
7 : XZ2
8 : OFF
ROM cassette condition
Off : Not mounted
On : Mounted
Fiscal ROM Board condition
0 : Connected
1 : Not connected
2nd Display condition
Off : Connected
On : Not connected
Menu switch conditon
0 : Switchs are both off condition.
1 : Menu 1
2 : Menu 2
Paper near end sensor
Off : Normal (Paper end switch OFF)
On : Near end (Paper and switch ON)
ROM switch
0 : Switch off
1 : Switch on
Drawer sensor
Off : Drawer close
On : Drawer open
INIT switch
0 : Switch off
1 : Switch on