VIC20digitizer (for VIC 20) - c0pperdragon/LumaCode GitHub Wiki
The VIC20digitizer is a small modification board for the VIC 20 home computer. It can be easily (without soldering) installed by putting it between the VIC and its socket and connecting the output to an RCA jack that needs to be installed in a convenient spot in the case. Using a Lumacode-compatible upscaler (the RGBtoHDMI for example), you get pixel-perfect HDMI.
Installation
Remove the VIC chip from its socket, insert the mod board in the socket and put the VIC back on top. Take care to get the orientation of both parts right. Look at the notch to see how it needs to be orientated. In the case your VIC is directly soldered to the board, you need to unsolder it first and add a socket (a task that is not for beginners and needs special tools)
Drill a hole in the case in some convenient spot for the RCA jack and install the jack and connect the cables.
Details on color encoding
The VIC20digitizer uses the exact same system for encoding its 16 colors as does the VICIIdizer. The same lumacode sample values map to the same color indizes as on the C64. The lower 8 colors also already look identical.