A CPLD Video Card With VGA And NTSC

Here is a project to generate VGA and NTSC from a CPLD.

The brains of the outfit is a $5, 100-pin CPLD from Xilinx. Apart from that, the rest of the components are a crystal, PLL, and an almost hilarious number of resistors for the R2R ladder. The one especially unique component is the 25.056815 MHz crystal – multiply by that by two, and it’s fast enough to drive a VGA monitor. Divide the crystal by seven, it’s the 3.579545 MHz you need for an NTSC colorburst frequency. That’s VGA and NTSC in a single programmable logic project, something the one FPGA project we could find that did color NTSC couldn’t manage.

via hackaday.com