[sidhack] SID Pin Descriptions

I finally found some pin descriptions, I thought I would share...

6581 / 8580 Signal Description
------------------------------

Pin(s)  Signal      Dir    Description

  1-2     CAP        ?     Capacitor #1 for the programmable filters.
         1A/B              6581: 470pF, 8580: 22nF*. Note that both
                           capacitors (see pin 3-4) should have the same
                           value. [1] recommends 2200pF for normal
                           operation, which was AFAIK never used in the
                           C64.

  3-4     CAP        ?     Capacitor #2 for the programmable filters. See
          2A/B             pin 1-2.

   5      /RES      in     RESet. If this line remains LOW for at least
                           10 ø2 cycles, all internal registers reset to
                           zero and the audio output is turned off.

   6       ø2       in     Phi2**. System clock cycle. All data bus
                           action takes place only when ø2=1.

   7      R/-W      in     Read/Write. 0=write access, 1=read access.

   8      /CS       in     Chip select.0=data bus valid, 1=data bus high
                           impedance state (tri-state).

 9-13    A0-A4      in     Address bits 0-4 for selecting one of the 29
                           registers.

  14      GND        -     GrouND (0V). To reduce noise, this line should
                           be connected separately to the power supply.

 15-22   D0-D7   in / out  Data bits 0-7.

  23     POT Y      in     Potentiometer Y. Analog input #2 for paddles.
                           (ADC#2)

  24     POT X      in     Potentiometer X. Analog input #1 for paddles.
                           (ADC#1)

  25      Vcc        -     Supply voltage. +5V.

  26     EXTERN     in     External Input. Max. input 0.6V.
          IN

  27     AUDIO      out    Audio output of all voices.
          OUT

  28      Vdd        -     Secondary voltage. +12V (6581) or +9V (8580).

*  You might find 330pF in some boards, too.
** The 'ø' is used as Greek 'phi' here.

-------------------
[1] C64 Programmer's Reference Guide (excerpt)


Author: Marc-Jano Knopp <mjk@c64.org> on 97/11/21
Source: http://mjk.c64.org