DFO mod (Dual Frequency Oscillator) for Neo Geo MVS (and more?)

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    • Max_Power wrote:

      Does anyone know if someone sells any more of these ?

      I was able to get one from a fellow member but I need 2 to 3 more.

      It made the output fps almost 60 and I was hearing a buzzing noise from my TV previously.

      :)
      i've just got one of these clock generators:
      https://learn.adafruit.com/adafruit-si5351-clock-generator-breakout/

      configured it to output default 24mhz on clk0, 24.305909760 mhz on clk1:

      C Source Code

      1. #include <Wire.h>
      2. #include <Adafruit_SI5351.h>
      3. Adafruit_SI5351 clockgen = Adafruit_SI5351();
      4. /**************************************************************************/
      5. /*
      6. Arduino setup function (automatically called at startup)
      7. */
      8. /**************************************************************************/
      9. void setup(void)
      10. {
      11. Serial.begin(9600);
      12. Serial.println("Si5351 Clockgen Test"); Serial.println("");
      13. /* Initialise the sensor */
      14. if (clockgen.begin() != ERROR_NONE)
      15. {
      16. /* There was a problem detecting the IC ... check your connections */
      17. Serial.print("Ooops, no Si5351 detected ... Check your wiring or I2C ADDR!");
      18. while(1);
      19. }
      20. Serial.println("OK!");
      21. /* INTEGER ONLY MODE --> most accurate output */
      22. /* Setup PLLA to integer only mode @ 900MHz (must be 600..900MHz) */
      23. /* Set Multisynth 0 to 112.5MHz using integer only mode (div by 4/6/8) */
      24. /* 25MHz * 36 = 900 MHz, then 900 MHz / 8 = 112.5 MHz */
      25. Serial.println("Set PLLA to 768MHz");
      26. clockgen.setupPLL(SI5351_PLL_A, 30, 18, 25);
      27. Serial.println("Set Output #0 to 24MHz");
      28. clockgen.setupMultisynth(0, SI5351_PLL_A, 32, 0, 1);
      29. clockgen.setupRdiv(0, SI5351_R_DIV_1);
      30. /* FRACTIONAL MODE --> More flexible but introduce clock jitter */
      31. /* Setup PLLB to fractional mode @616.66667MHz (XTAL * 24 + 2/3) */
      32. /* Setup Multisynth 1 to 13.55311MHz (PLLB/45.5) */
      33. Serial.println("Set PLLB to 729.1772MHz");
      34. clockgen.setupPLL(SI5351_PLL_B, 29, 10443, 62500);
      35. Serial.println("Set Output #1 to 24.305906MHz");
      36. clockgen.setupMultisynth(1, SI5351_PLL_B, 30, 0, 1);
      37. clockgen.setupRdiv(1, SI5351_R_DIV_1);
      38. /* Multisynth 2 is not yet used and won't be enabled, but can be */
      39. /* Use PLLB @ 616.66667MHz, then divide by 900 -> 685.185 KHz */
      40. /* then divide by 64 for 10.706 KHz */
      41. /* configured using either PLL in either integer or fractional mode */
      42. Serial.println("Set Output #2 to 10.706 KHz");
      43. clockgen.setupMultisynth(2, SI5351_PLL_B, 900, 0, 1);
      44. clockgen.setupRdiv(2, SI5351_R_DIV_64);
      45. /* Enable the clocks */
      46. clockgen.enableOutputs(true);
      47. }
      48. /**************************************************************************/
      49. /*
      50. Arduino loop function, called once 'setup' is complete (your own code
      51. should go here)
      52. */
      53. /**************************************************************************/
      54. void loop(void)
      55. {
      56. }
      Display All

      will test it when i get home.
    • someitalian123 wrote:

      nam9 wrote:

      mmmonkey wrote:

      I see it's possible to use a Raspberry Pi as a programmer so will try that first.
      Interesting! Link?I have a Hex file I built a while back.. It may work, but I didn't test it as the DFO i sourced came pre-programmed...

      MVS24Clock.zip
      Has anyone been able to test this hex file to verify functionality?
      I am now able to verify that this hex file does indeed work. I programmed a 5v DFO purchased from otakus-store.net using a Raspberry Pi Zero W. If anyone is planning to program using a raspberry pi just be sure to uncomment the appropriate lines in the /boot/config.txt file first.