The Adafruit memory display https://www.adafruit.com/product/3502 was a ridiculous board, a giant board just dedicated to shifting the logic levels & regulating the voltage for a tiny display.  It's mane advantage is a 300mA voltage regulator suitable for powering the entire project.

Reviewing the flash rehabilitation https://hackaday.io/project/173855-rehabilitate-a-40-year-old-flash RESISTOR B has a voltage from 0 - 2.5 but is connected to a resistor inside the flash.  It therefore has to be connected to an adjustable resistor rather than a DAC to see the right voltage.

AVCC has to be connected for PORTC to work.

Mock up.

The display shows its 1st dynamic data since it was bought 5 years ago.  They don't make them like this anymore.

The only way to fit any graphics in the atmega328 was to calculate each pixel in place & scale up a commodore 64 font file.  The font was enlarged 8x to get the biggest characters & 4x to get the small characters.  It undoubtedly would look less like an atari 2600 & more like a macbook if the atmega had more memory.  The commodore 64 characters took 152 bytes.  Storing 1:1 characters would take 7040 bytes.  Maybe it would fit, but it wouldn't be nostalgic.