The E-Z Color Graphics Interface was a project published in Byte magazine
about 40 years ago that put the Texas Instruments TMS9918A video generator
(used in the TI-99/4A, ColecoVision, and MSX-compatible computers) into the
Apple II. It's a fairly simple design: the chip, the 16K of DRAM it needs
to work, and minimal glue logic (just a 74LS00). The 9918A also found its
way into products such as the Third Millennium Arcade Board (reviewed by
Creative Computing in February 1984), and both boards are emulated in MESS.
(MESS even offers emulation of hypothetical EZCGI variants with the later
Yamaha V9938 and V9958, which offer more features.)

I've recaptured the EZCGI schematic in KiCad 6 and knocked together a PCB
layout that at least borrows from the component placement of the original
(since the article didn't provide a layout, just a photo of a prototype).
The schematic isn't a 1:1 copy of the original, but a reinterpretation of
the design in a modern EDA idiom (labeled nets instead of wires and buses
all over, hierarchical design, etc.). It does use all through-hole
construction, with the originally-specified 4116 DRAM. It doesn't seem to
be any harder to find than the 9918A: you're most likely going to need to
hit up eBay for both. (There is an RC2014-compatible card that uses extra
logic to replace the 4116s with newer SRAM, if you're inclined to go that
way...search for "RC2014 9918A" and you'll find it.)

If anyone wants to take a look and verify that I didn't screw anything up,
you might take a look in here:

https://gitlab.com/salfter/a2-9918/

If you don't have KiCad installed, you can pull the schematic as a PDF:

https://gitlab.com/salfter/a2-9918/-/blob/master/a2-9918.pdf

Gerbers and a STEP model are also in the package.

I'm in the middle of building an RC2014-ish (probably compatible) system
that will have a V9958 graphics card, but this would be a nice project to
bring a bit of the first computer I owned (the TI-99/4A) to the second
computer I owned (the Apple II).

The original schematic (and the article that accompanies it) can be found in
the Internet Archive:

https://archive.org/details/byte-magazine-1982-08-rescan/page/n65/mode/2up

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