Casio CTK-750 Service Manual page 7

Nomenclature of Keys
C#2 G#2 A#2 C#3
D#2 F#2
C2 D2 E2 F2 G2 A2 B2 C3 D3
Button Matrix
KI1
KO0 Split
KO1 Transpose
KO2
KO3 3
KO4 2
Accomp.
KO5
Volume
Synchro/
KO6
Ending
KO7 Mode
Reset Circuit
Battery set
VDD
RESET
Reset IC
S8053ANO
POWER
From power switch
D#3 F#3 G#3 A#3
C#4 D#4
E3 F3 G3 A3 B3 C4 D4 E4
KI2 KI3
Layer Upper 1
Tune MIDI
Track 4
Chord 1
6 9
5 8
Song
Accomp.
Memory
Variation Normal/
/Fill-In Fill-In
A C
VDD
CPU
-RESET
HD6433298A18P
WR
— 5 —
F#4 G#4 A#4 C#5 D#5 F#5 G#5 A#5
F4 G4 A4 B4 C5 D5 E5 F5 G5
KI4 KI5
Lower 1 Lower 2
Jack Rhythm
Track 5 Track 6
Chord 2 Chord 3
Touch
Demo
Responce
Track 1 1
Track 0
Intro F
Start/
E
Stop
VDD
Gate Array
UPD65005C-578
VDD
-SRAM
Working Strage RAM
HM62256ALP-10
D#6 F#6 G#6
C#6 A#6
A5 B5 C6 D6 E6 F6 G6 A6 B6
KI6 KI7
Upper 2
Tone Play Style
Track 2 Track 3
Rhythm Bass
Digital
Resistration
Effect
4 7
- +
D B
Tempo Tempo
Down Up
DVDD
DSP
HG51A115A01FD
DVDD
Key Touch LSI
HG52E35
C7