Casio GZ-500 manual Filter Block

The following table shows the pin functions of LSI107.

Pin No.	Terminal	In/Out	Function
1	REQB	Out	Not used
2, 3, 60 ~ 63	FI8 ~ FI10,	In	Not used. Connected to + 5V.
	SI8 ~ SI10
4	VCC	In	+5V source
5	CRDB	In	Read enable signal input
6	CWRB	In	Write enable signal input
7	CCBB	In	Chip select signal input
8, 9, 11	T, STBY, W	In	Not used. Connected to +5V.
10	RESB	In	Reset signal input
12	CKI	In	10 MHz clock input
13, 14	TMD, TST	In	Not used. Connected to ground.
15	CKO	Out	Not used.
16	GND	In	Ground (0V) source
17	XIN	In	Not used. Connected to ground.
18	XOUT	Out	Not used.
19	TRES	In	Not used. Connected to ground.
20 ~ 23, 25 ~ 28	CD0 ~ CD7	In/Out	Data bus
24	GND	In	Ground (0V) source
29 ~ 31	CR0 ~ CR2	In	Address bus
32	VCC	In	+5V source
33 ~ 39, 41 ~ 43	FI0 ~ FI7,	In	Key input signal input
53 ~ 55, 57 ~ 59	SI0 ~ SI7
40	VCC	In	+5V source
44 ~ 47, 49 ~ 52	KC0 ~ KC7	Out	Key scan signal
48, 56	GND	In	Ground (0V) source
64	VCC	In	+5V source

FILTER BLOCK

Since the sound signals from the DAC are stepped waveforms, the filter block is added to smooth the waveforms.

10V22∝-

+

To main volume

IC105

M5218APR

C333(H)		AVDD	AVDD
	Q107/108		18K
	2SC1740
1K	1K	1K
C222(H)	C103(H)	1K	1K
AG	AG	AG	AG

50V1∝

From the DAC

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