76477

Complex Sound Generator

Pinout

DIP28
                                       +---\/---+
             ENVELOPE SELECT 1 (INPUT) | 1    28| ENVELOPE SELECT 2 (INPUT)
                                GROUND | 2    27| MIXER SELECT C (INPUT)
          EXTERNAL NOISE CLOCK (INPUT) | 3    26| MIXER SELECT A (INPUT)
          NOISE CLOCK RESISTOR (INPUT) | 4    25| MIXER SELECT B (INPUT)
 NOISE FILTER CONTROL RESISTOR (INPUT) | 5    24| ONE-SHOT CONTROL RESISTOR (INPUT)
NOISE FILTER CONTROL CAPACITOR (INPUT) | 6    23| ONE-SHOT CONTROL CAPACITOR (INPUT)
        DECAY CONTROL RESISTOR (INPUT) | 7    22| VCO SELECT (INPUT)
 ATTACK/DECAY TIMING CAPACITOR (INPUT) | 8    21| SUPER LOW FREQUENCY OSC. CONTROL CAP. (INPUT)
                 SYSTEM ENABLE (INPUT) | 9    20| SUPER LOW FREQUENCY OSC. CONTROL RES. (INPUT)
       ATTACK CONTROL RESISTOR (INPUT) |10    19| PITCH CONTROL (INPUT)
    AMPLITUDE CONTROL RESISTOR (INPUT) |11    18| VCO CONTROL RESISTOR (INPUT)
             FEEDBACK RESISTOR (INPUT) |12    17| VCO CONTROL CAPACITOR (INPUT)
                          AUDIO OUTPUT |13    16| EXTERNAL VCO CONTROL (INPUT)
                                   Vcc |14    15| VREG (INPUT)
                                       +--------+

Frequency

DIP28
Set reader to FREQ, put black probe to GND, red probe to 3 to measure CPU clock

External links

SN76477 page on Wikipedia
Reverse engineering the 76477

Files

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  SN76477 Datasheet