SID internals

NOTE: the content here is outdated, the project has moved to https://github.com/libsidplayfp/SID_schematics/wiki

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SID internals documentation

Reverse-engineering of the MOS 6581/8580 SID schematics by Leandro Nini and ttlworks, based on silicon layouts photographed by Michael Huth and revectorized and annotated by Tommi Lempinen

Control Logic

* [SID internals - Clock]
* [SID internals - Reset]
* [SID internals - Address Decoders]
* [SID internals - Data Bus]
* [SID internals - Registers]

Waveform Generator

* [SID internals - Oscillator]
* [SID internals - Pulse Waveform]
* [SID internals - Triangle Waveform]
* [SID internals - Noise Generator]
* [SID internals - Wave Selector]

Envelope Generator

* [SID internals - Envelope Overview]
* [SID internals - Envelope Counter]
* [SID internals - Sustain Comparator]
* [SID internals - ADSR registers]
* [SID internals - Counter Logic]
* [SID internals - Exponential Divider]
* [SID internals - LFSR15 counter]
* [SID internals - LFSR5 counter]

Analog Stage

* [SID internals - Analog stage overview]
* [SID internals - 6581 DACs]
* [SID internals - 6581 Opamps]
* [SID internals - 6581 Filter overview]
* [SID internals - 8580 DACs]
* [SID internals - 8580 Virtual ground]
* [SID internals - 8580 AC Voltage divider]
* [SID internals - 8580 Filter overview]
* [SID internals - 8580 Opamps]
* [SID internals - Audio output]

Paddles

* [SID internals - Paddles Overview]
* [SID internals - Paddle counter]
* [SID internals - POT registers]

External Filter

* [SID internals - External filter]

References

* Die shots: http://retronn.de/imports/commodore_chips.html
* Original layouts: http://oms.wmhost.com/misc/
* Reverse-engineering discussion: http://forum.6502.org/viewtopic.php?f=8&t=4150