This is a tested and working project.

No waste of big EPROMs, no jumpers, no configurations, no SMD.

It uses a cheap 2732 EPROM that can be easily found on Aliexpress, eBay, etc.

What you need:

1) The PCB from PCBway, of course;

2) a 2732 EPROM programmed with the characters ROM (get the zip file from this page);

3) 1x 24 pin wide socket [1];

4) 2x 12Pin Connector Header Round pins [2] Male pitch 2.54mm

(get something like this one: https://www.aliexpress.com/item/4000341349347.html and cut in two pieces of 12 pins each)

[1] You will need two sockets if the VIC-20 ROM isn't on socket yet (unless you decide to solder the adapter directly on the VIC-20 board - not recommended);

[2] I strongly suggest to use the thin, round pins type, because the square, thick ones tend to damage the socket.

How to proceed:

1) solder the 2x connector headers on the "VIC-20" side, as marked on the PCB (the 2nd and the 4th rows looking at the board with the notch oriented upside - also look at the attached pictures for more info). To keep the headers in the right alignment while you're soldering them, I suggest you to put headers into a socket to keep them in the right position.

2) Solder the socket on the "EPROM" side (on the left side, as marked on the PCB; look at the pictures);

3) Program the EPROM with the image from the ZIP files I provided;

4) Put the adapter with the EPROM installed into the VIC-20 character ROM socket.

Note: If the Character ROM isn't on socket, you will need to remove it and put a socket. If the chip is broken and ready for the junk bin, it can be easily removed simply cutting all the pins from the chip, removing the chip and then un-solder every pin, once at a time. Take your time, because the Commodore boards are known to be weak and it's easy to damage them if you don't take care.

NOTE:

Inside the Zip file I provided the C=64 characters ROM image too. The VIC-20 and C=64 images are fully compatible, so you can use any of them in a C=64 or VIC-20. The C-64 will produce a thicker font.

(BEWARE: ONLY THE FIRMWARE IMAGES ARE INTERCHANGEABLE, NOT THE ADAPTERS! This adapter is intended for the VIC-20 only and will not work in the Commodore 64)