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  1. Elektron72's post in YM2151 Fine detuning was marked as the answer   
    DT1 uses sign-magnitude representation to allow for both positive and negative detunes. Values 1-3 are positive detunes, while 5-7 are negative. Setting one operator's DT1 to 3 and the other to 7 will produce a more powerful effect.
  2. Elektron72's post in Trying to wait for VSYNC that never happens crashes my game (C programming) was marked as the answer   
    When the VSYNC interrupt occurs, the system jumps through the vector located at $0314, which points to the kernal interrupt handler (unless the vector has been modified). This routine performs several functions (polling the keyboard, updating the system timer, etc.). Before returning, the routine clears the interrupt status in ISR to prevent the interrupt from immediately triggering again. To properly wait for VSYNC, you will need to modify the vector at $0314 to point to your own interrupt handler. A custom handler will likely set a value somewhere in memory indicating that an interrupt has occured, and then jump to the original handler.
  3. Elektron72's post in triggering screen 0, from "c" was marked as the answer   
    In order to change to 40x30 mode, you should use the screen_set_mode kernal routine. In addition to changing the screen size, this routine sets some variables in the kernal that are used to determine when to scroll the screen.
  4. Elektron72's post in Assigning IRQ vectors in cc65 was marked as the answer   
    After making some changes to the code, I was able to get the following version to compile:
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