Casio WK-1800 Service Manual

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MEMORY DEVICES
Each memory device has the following data.
1 RAM1 :
S-RAM for operation program, Register, Pattern, Song
and SMF data from FDD. (Lower part of data bus)
2 RAM2 :
S-RAM for operation program, Register, Pattern, Song
and SMF data from FDD. (Upper part of data bus)
3 Internal ROM of CPU :
Main program data for system operation
4 Internal RAM of CPU :
Work area for system operation
5 ROM1 :
Demo, Accompaniment data, Song, Pattern, Synth, Disk
mode
6 ROM2 :
Sound Waveforms/Tone data Digital sound effect
7 Working RAM :
Work area for DSP
CPU
RAM1
1
1 Mbit
LSI7
ROM
RAM
3
4
512 kbit
16 kbit
DSP
LSI9
LSI3
Working RAM
7
256 kbit
LSI4
Internal Memory
ROM1
5
32 Mbit
LSI1
RAM2
2
1 Mbit
LSI8
ROM2
6
32 Mbit
LSI2
VDD
Battery set
RESET
CPU
HD6433048SA89F
LSI9
FDD Controller
HD63266F
LSI10
RESET
Power Supply
Circuit
DSP
HG51B155FD
LSI3
RESB
RESB
Key Controller
TC190C020AF-001
LSI6
DVDD
DVDD
DVDD
VDD
DVDD
RESET
APO
PWSW
From power switch
RES
NMI
PB0
PA7
RESET
PW/SW ON
APO
DVDD
(5V)
Initial reset
When batteries are set or an AC adapter is connected, the reset IC provides a low pulse to the CPU.
When the power switch is pressed, the CPU receives a low pulse of POWER signal. The CPU first raises
APO signal to +5 V to generate DVDD voltage, then raises RESET signal to +5 V. During this period the
DSP, the key controller and FDD controller LSIs initialize their internal circuits.
RESET CIRCUIT

Casio WK-1800 Specifications

General

Number of Keys	76
MIDI	Yes
Display	LCD
Effects	Reverb, Chorus
Weight	8.5 kg
Polyphony	32
Speakers	Yes
Power Supply	AC adapter or batteries
Floppy Disk Drive	Yes
Connections	Headphones, MIDI In/Out, Sustain pedal
Sequencer	6 tracks