Today's update is one of those "it's really coming together" type updates.

Since you're reading text and you'll probably scroll down anyway, let me blow the surprise: it's VGA and NTSC test patterns.  On a 64 macrocell CPLD.  From a single, 3.5795454 MHz clock source.

Here's what you'll need to build it:

My code, conveniently located on the Git Repository for VGAtonic and MIT'd for your consumption: https://github.com/dqydj/VGAtonic/tree/master/ColorTest

• 3.5795454 MHz crystal (or a way to get it - 14.318 divided by 4 works)
• A switch (decide on NTSC or VGA mode)
• CPLD/FPGA - note that it needs to allow dual edged flip flops - or you'll have to update the logic to handle 2x the clock.  The Coolrunner II XC2C64A in the video allows this.
• An NE564 PLL
• 5V Power source, 3.3V regulator, and possibly a way to step down the 5V clock from the PLL (I ignored it, but you shouldn't - it'll likely eventually break the CPLD).
• A bunch of passives to build the resistor ladders and PLL support:

PLL:

• 18 pf Capacitor (I'm using a bunch of 10s and 12s in parallel/series to get close in my image)
• 2x .0047uF Capacitor
• 22k ohm Resistor
• 47 pF Capacitor
• 3x 510 ohm Resistor

VGA:

• 24x 510 ohm Resistor (I use them in parallel to get 255 ohm in my ladder)
• Generic VGA Connector

NTSC:

• 12x 510 ohm Resistor (Again, in parallel to get 255 ohms as well)
• 1k ohm Resistor
• 1.5k ohm Resistor
• Generic RCA plug

And the NTSC/VGA resistor ladder DAC detail:

I've got it on a beast of a breadboard - one of those 4 column deals.  Here's what it looks like:

Some notes:

• Separate your grounds with homeruns back to the power supply, if you can.  It was easy on my breadboard.
• Use a buffer or a resistor voltage divider or something to knock that clock down to a safe level for your CPLD.
• Add decap to the PLL and the CPLD - you've got long wires and the disgusting parasitics of a breadboard.

Hope someone finds this useful!

I'm sufficiently confident now that VGAtonic is realistic - I'll be designing the PCB next, and I'll throw together the framebuffer code at the same time.