Re: FPGATED prototype

On 1/15/21 1:27 PM, Istvan Hegedus wrote:
> Hi All,
> 
> FYI I have successfully tested my FPGATED drop-in prototype in a Plus4 and
> C16! It works perfectly, so far it runs most of the programs that I have
> tried.
> The prototype uses just a 2 layers PCB and a TQG144 Xilinx Spartan6 LX4 to
> keep costs down, however it needed an smd IC header because through hole
> would have not fit. The size of the PCB is just inside the limits, it fits
> the Plus4 as well.
> Though it works well my plan is to create a new design with a 4 layers PCB,
> through hole IC header and a Spartan6 with CPG196 package which is much
> smaller than a TQG144 one.
> 
> See project logs at https://hackaday.io/project/11460-fpgated
> 
> I will create a youtube video too to demonstrate its quality.
> I have only tested PAL operation, NTSC color phases I need to fix
> (currently they are set based on the datasheet which I believe is not
> correct). If someone knows the exact NTSC color phases please let me know
> (I have analyzed VICE sources so have something in hand). I am also waiting
> for a proper crystal from China to change one of my C16 motherboards to
> NTSC. Then I can start to test my old CRT TVs to see which can handle
> NTSC...

The NTSC crystal is 14.318 MHz. That's a VERY common crystal. Check your 
junk pile for old boards, many PLL ICs on PC mainboards and cards use 
this crystal for their base clock.

  Gerrit