The New C64 ‘TUNING’ Board

This is the new C64 “TUNING” Board

A new C64 board with a lot of useful C64 modifications directly on the board. 

  • “Tuning” Placeholder: Here you can place for instance an Arduino or something else with headers to implement other functions you want (OSD, Keyboard Mapper, Midi, Lights, …)
  • 3 x I2C Ports with SDA/SCL Pullup Resistors (for RTC, Radio, Accelerometer, …)
  • Tripple SID Sockets (3x 6581 and/or 8580) and 12V/9V and Stereo L/R Jumpers
  • Optional 8580 Digifix (Jumper)
  • Ready for use 3x “BEAUTIFUL QUAD” SID (12 SIDs = 36 Voices)
  • Pin-Headers on Board: A5,A8,IO1,IO2,A6,A7 for SID Cables
  • 2 x 2 Pin Headers for Soft and Hard Reset Button (HF Modulator Case hole)
  • New Video circuit for Composite and S-Video Out 
  • Standart RF Modulator Connector Pins (2x 4 Pins) to place your own Modulator/Video Box (half the height)
  • Power Input 5V without regulator, or Power Input 7,5-12V with 5V regulator max. 3A
  • Enough Place to use Textool IC Sockets
  • A lot Measuring Points (AEC, BA, PHI, TOD, …) 1.3mm holes (Scope friendly)
  • Kernel/Basic ROM Switch for 1:1 pin compatible AT28C256 32K EEproms
  • Usable VIC II 656x/856x Chips with 12V/5V Jumper
  • NE555 for 50/60 Hz TOD Pulse (adjustable with Potentiometer)
  • Removed POTX/Y Pins of the 2nd Gameport (Mouse on Port 1 only)
  • Possible to Sideload Userport ~9V over 2 headers or to use 9V DC with 2 Jumpers
  • Mixed EMV Protection from C64 I and II
  • Ready for use 8701, SRAM Dual Socket Adapter, SID Replicas
  • Placeholder for 8701 Replacement: SI5351 Breakout -Board (7€)
  • Power LED Connectors on both sides (L/R)
  • Power Consumption only ~4 Watts (5V/760mA)


This Board is FPGA/CPLD/SMD Free, because I wanted the soldering to be as easy as possible and it should be easy to repair by everyone.

Next month I will order some of these in China.