Sony XR-3750 Service Manual page 19

Pin No. Pin Name
72 BUSON
73 SYSRST
74 VREG
75 GND
76 X OUT
77 X IN
78 CE
79 VDD1
80 RESET
*1 loading/tape operation motor control
MODE
TERMINAL
LM LOD (pin 8)
LM EJ (pin 9)
I/O
O Bus on/off control signal output terminal "L": bus on Not used (pull up)
O Reset signal output terminal "L": reset Not used (pull up)
O CPU regulator output terminal Connected to capacitor
— Ground terminal
O Main system clock output terminal (4.5 MHz)
I Main system clock input terminal (4.5 MHz)
I CPU chip enable signal input (fixed at "H")
— Power supply terminal (+5V)
System reset signal input from the reset signal generator (IC551) and reset switch (S551)
I
"L": reset "L" is input for several 100 msec after power on, then it changes to "H"
LOADING/ EJECT/
STOP
FORWARD REVERSE
"H" "L"
"H" "H"
Function
BRAKE
"H" "L"
"L" "L"
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