CASIO CPS85
Service Manual

DAC (IC1: UPD6379GR)
The DAC receives 16-bit serial data output from the DSP. The data contains digital sound data of the melody, chord, bass, and percussion for the right and left channels. The DAC converts the data into analog waveforms and output them to each channel separately.
Synch signal SINC L OUT DAC LSI6 UPD6379GR R OUT CLK SI Word clock LRCK WCKO Bit clock BCKI Data SO DSP LSI1 HG51B277FB Data SI Word clock WCKI Bit clock BCK LRCK SO SCK1 CPU LSI4 GT913F

FILTER BLOCK
Since the sound signals from the DAC are stepped waveforms, the filter block is added to smooth the waveforms.
AVCC
2.7 K

To main volume 15 V10 µ
8 – 6 5 +

C472(H)

L

7 4

2

10 K

10 K

10 K 10 µF

R154

Left From DAC

AG M5218APR (1/2) × 2 IC104 – + 2 3
C221B(A)

AG AVCC C472(H)

AG 2.2 K

15 V10 µ

R

1

2

10 K

10 K
C152(H)

10 K

100 K

To main volume

AG

10 µF

Right From DAC

AG

AG

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