Casio CPS-85 Service Manual

POWER VOLUME

OFF ON MIN MAX

CPS-85

DIGITAL EFFECT TONE MEMORY

TRANSPOSE

#

F

GA BC D EAB C#EF

PIPE

HARPSI-

STRINGS

SONG A

PIANO 1

E. PIANO 1

E. PIANO 2

PIANO 2

SELECT

ORGAN

CHORD

SYNTH-

VIBRA-

JAZZ

PHONE

ORGAN

SONG B

STRINGS

RECORD STOP START

CONTROL DEMO

1 510152025

ELECTRONIC KEYBOARD

CPS-85

CONTENTS

Page

Specifications ............................................................................................................................................ 1

Block Diagram........................................................................................................................................... 3

Circuit Description ..................................................................................................................................... 4

Major Waveforms .................................................................................................................................... 11

Printed Circuit Boards ............................................................................................................................. 12

Schematic Diagrams ............................................................................................................................... 13

Exploded View ....................................................................................................................................... 19

Parts List ................................................................................................................................................. 21

SPECIFICATIONS

GENERAL

Keyboard: 88 full size keys with initial touch response
Polyphony: 24 notes maximum
Tones: 10 (with layering)
Tuning curves: 3 types (preset for each tone)
Digital effects: REVERB
Demo tunes

Number of tunes: 10
Titles: 1. Grande valse brillante

2. Turkish March

3. One-Eighty

4. Opaque Mist

5. Harmonious blacksmith

6. Dream Sequence

7. Fugue in G minor

8. Moveable Blues

9. Rainbow

10. Ave Maria

Playback: Repeat sequential play of all tunes; playback always starts from begin-

ning of tune

Manual memory

Type: Real-time recording and playback
Number of songs: 2 (SONG A, SONG B)
Capacity: Approximately 1,200 notes (SONG A + SONG B)
Back-up: Power supplied by batteries or AC adaptor

Pedal: Damper
Other features Transpose (±1 octave, semitone steps)

Tuning (adjustable, A4 = 440 Hz ± 50 cents)

MIDI: 8-channel multi-timbre reception
Speakers: 14 cm × 2 (6 W + 6 W)
Terminals: PHONES (standard stereo jack × 1)

LINE OUT (standard mono jack × 2)

Output impedance: 1.0 KΩ
Output voltage: 1.5 V (RMS) MAX

LINE IN (standard mono jack × 2)

Input impedance: 47 KΩ
Sensitivity: 200 mV

MIDI OUT/IN (DIN jack × 2)

— 1 —

DAMPER PEDAL (standard mono jack × 1)
DC 12 V (DC jack × 1)

Power supply Dual power supply system

Batteries: 6 D-size batteries
Battery life: Approximately 4 hours on manganese batteries
AC adaptor: AD-12
Auto power off: Turns power off approximately 5 minutes after last key operation.

Enabled under battery power only, can be disabled manually.

Power consumption: 18 W
Dimensions (HWD): 100 × 1372 × 414 mm (without stand)

(3-15/16 × 54-1/16 × 16-5/16 inches)

Weight: Without stand and excluding batteries 16.8 kg (37.1 lbs)

ELECTRICAL

Current drain with 12 V DC:

No sound output 240 mA ± 20 %
Maximum volume

with 24 keys from C1 to B2 pressed in Jazz organ tone 2050 mA ± 20 %
Volume: maximum, Touch response: maximum

Phone output level (Vrms with 8 Ω load each channel):

with key E3 pressed in Jazz organ tone L-ch 60 mV ± 20 %

R-ch 65 mV ± 20 %

Speaker output level (Vrms with 4 Ω load each channel):

with key E3 pressed in Jazz organ tone L-ch 860 mV ± 20 %

R-ch 920 mV ± 20 %

Lineout output level (Vrms with 47 kΩ load each channel):

with key B5 pressed in Jazz organ tone L-ch 140 mV ± 20%

R-ch 160 mV ± 20%

Minimum operating voltage: 6.5 V

— 2 —

BLOCK DIAGRAM

Working Storage

RAM (64K-bit)

LSI2

HY6264ALLJ-70

MIDI

INOUT

Buttons

Sound Source ROM

(8M-bit)

LSI3

MX23C1610MC-12

Effect RAM

(256K-bit)

LSI5

TC55257DFL-70L

EA0 ~

EA14

EIO0 ~

EIO7

MA0

~

MA12

MD0 ~ MD15

MA1 ~ MA19

MD0

~

MD7

DSP
LSI1

HG51B277FB

LRCK SO

BCK

KI0 ~ KI2

CPU
LSI4

GT913F

BCK, SO, LRCKMA0, MA1

SONGA
SONGB
DIGITAL EFFECT
SELECT
STOP

FI0 ~ FI10
SI0 ~ SI10

Keyboard

KC0 ~ KC7

Reset IC

IC 1

RN5VD35AA

LEDs

VDD

Speakers

Output

D/A Converter

LSI6

UPD6379GR

Rmel Lmel

Filter

IC104

Main

Volume

Pre. Amp.

IC103

Power Amplifier

IC101

LA4620

— 3 —

POWER (APO)
From CPU

Line In

Line Out

AVCCVDD VCC AVDD LVDD

Power Supply Circuit

Q101 ~ Q106

D108, D110, D111

6 × D-size batteries
AC adaptor AD-12

CIRCUIT DESCRIPTION

KEY MATRIX

0CK1CK2CK3CK4CK5CK6CK7CK

0IF)1(0A)1(0#A)1(0B)1(1C)1(1#C)1(1D)1(1#D)1(1E
0IS)2(0A)2(0#A)2(0B)2(1C)2(1#C)2(1D)2(1#D)2(1E
1IF)1(1F)1(1#F)1(1G)1(1#G)1(1A)1(1#A)1(1B)1(2C
1IS)2(1F)2(1#F)2(1G)2(1#G)2(1A)2(1#A)2(1B)2(2C
2IF)1(2#C)1(2D)1(2#D)1(2E)1(2F)1(2#F)1(2G)1(2#G
2IS)2(2#C)2(2D)2(2#D)2(2E)2(2F)2(2#F)2(2G)2(2#G
3IF)1(2A)1(2#A)1(2B)1(3C)1(3#C)1(3D)1(3#D)1(3E
3IS)2(2A)2(2#A)2(2B)2(3C)2(3#C)2(3D)2(3#D)2(3E
4IF)1(3F)1(3#F)1(3G)1(3#G)1(3A)1(3#A)1(3B)1(4C
4IS)2(3F)2(3#F)2(3G)2(3#G)2(3A)2(3#A)2(3B)2(4C
5IF)1(4#C)1(4D)1(4#D)1(4E)1(4F)1(4#F)1(4G)1(4#G
5IS)2(4#C)2(4D)2(4#D)2(4E)2(4F)2(4#F)2(4G)2(4#G
6IF)1(4A)1(4#A)1(4B)1(5C)1(5#C)1(5D)1(5#D)1(5E
6IS)2(4A)2(4#A)2(4B)2(5C)2(5#C)2(5D)2(5#D)2(5E
7IF)1(5F)1(5#F)1(5G)1(5#G)1(5A)1(5#A)1(5B)1(6C
7IS)2(5F)2(5#F)2(5G)2(5#G)2(5A)2(5#A)2(5B)2(6C
8IF)1(6#C)1(6D)1(6#D)1(6E)1(6F)1(6#F)1(6G)1(6#G
8IS)2(6#C)2(6D)2(6#D)2(6E)2(6F)2(6#F)2(6G)2(6#G
9IF)1(6A)1(6#A)1(6B)1(7C)1(7#C)1(7D)1(7#D)1(7E
9IS)2(6A)2(6#A)2(6B)2(7C)2(7#C)2(7D)2(7#D)2(7E

01IF)1(7F)1(7#F)1(7G)1(7#G)1(7A)1(7#A)1(7B)1(8C
01IS)2(7F)2(7#F)2(7G)2(7#G)2(7A)2(7#A)2(7B)2(8C

0IK

1IKDROCERLORTNOCOMED

2IKPOTSTRATS

LATIGID
TCEFFE

/1ONAIP

2ONAIP

/1ONAIP.E

2ONAIP.E

-OPSNART

GES

ENO

AES

-CISPRAH

/DROH

-HPARBIV

-OPSNART

#FES

-OPSNART

EPIP

/NAGRO

ZZAJ

NAGRO

-OPSNART

#GES

-OPSNART

BES

/SGNIRTS

HTNYS

SGNIRTS

-OPSNART

#AES

-OPSNART

#CES

DES

TCELES

-OPSNART

/AGNOS

BGNOS

-OPSNART

EES

Note: Each key has two contacts,
the first conatct (1) and second contact (2).

Second contact (2)

— 4 —

Key

First contact (1)

FI

KC
SI

NOMENCLATURE OF KEYS

C#1 D#1 F#1G#1A#1

A#0

C#2 D#2 F#2 G#2A#2 C#3 D#3 F#3 G#3 A#3 C#4D#4 F#4 G#4 A#4 C#5 D#5 F#5 G#5 A#5 C#6 D#6 F#6 G#6 A#6 C#7 D#7 F#7 G#7 A#7

C2

D2 E2 F2 G2 A2 B2C1 D1 E1 F1 G1 A1 B1A0 B0 C3 D3 E3 F3 G3 A3 B3

C4 D4 E4 F4 G4 A4 B4 C5 D5 E5 F5 G5 A5 B5 D6 E6 F6 G6 A6 B6C6 C7 D7 E7 F7 G7 A7 B7 C8

POWER SUPPLY CIRCUIT

The power supply circuit generates five voltages as shown in the following table. VDD voltage is always
generated. The others are controlled by POWER signal from the CPU.

emaNegatloVfonoitareporoF

DDVV5+ MARtceffE,MARegarotsgnikroW,MORecruosdnuoS,PSD,CIteseR,UPC

DDVAV5+skcajnieniL,CAD
DDVLV5+pmaltoliP

CCVV9+reifilpmarewoP,skcajtuoeniL

CCVAV9+.pmAerP

RESET CIRCUIT

When batteries are set or an AC adapter is connected, the reset IC provides a low pulse to the CPU. The
CPU then initializes its internal circuit, and clears the working storage RAM.
When the power switch is pressed, the CPU receives a low level signal. The CPU sends POWER signal
to the power supply circuit, also sends a reset signal to the DSP.
When the keyboard is powered by batteries and no operation is made for six minutes, CPU drops signal
POWER to shut all the voltage except VDD off.

VDD

Power switch

Battery set

RESET

Reset IC

IC1

RN5VD35AA

NMI

CPU
LSI4

GT913F

VDD

Reset signal

PLE

HG51B277FB

POWER

SCKO

To power supply circuit

VDD

DSP
LSI1

— 5 —

CPU (LSI4: GT913F)

The 16-bit CPU contains a 1k-byte RAM, three 8-bit I/O ports, two timers, a key controller and serial interfaces.
The CPU detects key velocity by counting the time between first-key input signal FI and second-key SI from
the keyboard. The CPU reads sound data and velocity data from the sound source ROM in accordance with
the selected tone; the CPU can read rhythm data simultaneously when a rhythm pattern is selected. Then the
CPU provides 16-bit serial sound data to the DSP. The CPU also controls MIDI input/output and stores
sequencer data into the working storage RAM.
The following table shows the pin functions of LSI4.

.oNniPlanimreTtuO/nInoitcnuF

10DXTtuOtuptuolangisIDIM
20DXRnItupnilangisIDIM
30KCStuOtuptuolangis)FFOrewoPotuA;OPA(REWOP
41DXT— .dnuorgotdetcennoC.desutoN
51DXRnItupnilangisNOrewoP
61KCStuOtuptuoeslupgnizinorhcnysZHM1

9~7

01DNGAnIecruos)V0(dnuorG
11KCBtuOtuptuokcolctiB
21OStuOtuptuoataddnuoslaireS
31KCRLtuOtuptuokcolcdroW
41DNGnIecruos)V0(dnuorG

61,511TLX,0TLXtuO/nItuptuo/tupnikcolczHM42

71CCVnIecruosV5+

91,811DOM,0DOMnI.dnuorgotdetcennoC.lanimretnoitcelesedoM
02BTSRnItupnilangisteseR
12IMNnItupnilangisNOrewoP
22TNI— dnuorgotdetcennoC

03~32
83~137CK~0CKtuOlangisnacsyekroflanimreT
25~93
55~352IK~0IKnIlangistupninottubroflanimreT

65BNWMtuOPSDehtroflangiselbaneetirW

67~7591AM~0AMtuOsubsserddA
770BSCMtuOMORecruosdnuosehtroftuptuolangiselbanepihC
871BSCMtuOdesutoN
972BSCMtuOPSDehtroftuptuolangiselbanepihC
08CCVnIecruosV5+
18DNGnIecruos)V0(dnuorG
28BDRMtuOMORecruosdnuosehtroftuptuolangiselbanedaeR

89~3851DM~0DMtuO/nIsubataD

99ELPnI

00171PnItupniladeP

,0NA,CCVA

1NA

3IF~0IF
3IS~0IS

01IF~4IF
01IS~4IS

—.dnuorgotdetcennoC.desutoN

nIlangistupniyekroflanimreT

nIlangistupniyekroflanimreT

.tiucricylppusrewopehtot

lanimreteht,rotpadaCAnaybderewopsidraobyekehtnehW
langisfforewopotuadnestonseodUPCehttahtostlov0semoceb

— 6 —

DIGITAL SIGNAL PROCESSOR (LSI1: HG51B227FB)

The DSP receives 16-bit serial sound data from the CPU and adds the selected effect to the sound data using
the effect RAM. Then the DSP provides the sound data to the DAC. The DSP also drives LEDs.
The following table shows the pin functions of LSI1.

.oNniPlanimreTtuO/nI

08,4~14BP~0BP— .dnuorgotdetcennoC.desutoN
5OStuOCADehtroftuptuoataddnuoslaireS
6OKCWtuOCADehtroftuptuokcolcdroW
73DDVnIecruosV5+
8TSET—desutoN
9BSERnItupnilangisteseR

012SSVnIecruos)V0(dnuorG

21,11TUOX,NIXtuO/nItuptuo/tupnikcolczHM61
31IKCWnIUPCehtmorftupnikcolcdroW
41ISnIUPCehtmorftupniataddnuoslaireS
51IKCBnIUPCehtmorftupnikcolctiB
61CNISnItupnieslupgnizinorhcnyszHM1
712DDVnIecruosV5+

52~817OI~0OItuO/nIsubataD
62BECRtuOMARegarotsgnikrowehtroftuptuolangiselbanepihC
723SSVnIecruos)V0(dnuorG
821DAnIsubsserddA
92BEO— .dnuorgotdetcennoC.desutoN
03BEWnIlangiselbaneetirW
133DDVnIecruosV5+
232ECnI.evitcahgiH.tupnilangiselbanepihC
330DAnIsubsserddA
43B1ECnI.evitcawoL.tupnilangiselbanepihC

34,14~537OIE~0OIEtuO/nIMARtceffeehtrofsubataD

,84~64,44,24

16,95~15

54BECEtuOMARtceffeehtroftuptuolangiselbanepihC
94BEOEtuOMARtceffeehtroftuptuolangiselbanedaeR
053SSVnIecruos)V0(dnuorG
06BEWEtuOMARtceffeehtroftuptuolangiselbaneetirW

87,47,07,66,262SSVnIecruosdnuorG
97,57,17,76,362DDVnIecruosV5+

,96,86,56,46

37,27
77,677/6APtuOdesutoN

41AE~0AEtuOMARtceffeehtrofsubsserddA

5AP~0APtuOtuptuolangisnacsnottuB

noitcnuF

— 7 —