How would one display a fullscreen 3 level grey image on the screen in Axe?

Nonono. I have fullscreen hex images. How do I display them on the screen?

Try this:

Copy(A,L6,768)
Copy(B,L3,768)
Repeat getkey(15)
DispGraphr
End

Replace "A" with a pointer to the picture in the front layer, and "B" with a pointer to the picture in the back layer.  They can either be in the program code itself (pic absorption or hex code) or they can be pointing to an OS pic in ram or even archive if you use a file variable instead of the pointer.

You. Are. A. Lifesaver.

What format are the 3-level gray images in? (other than hex, that's already been established)

In two separate image (or sprite/tile). First layer is transparent (using the white) and black and second layer is white and gray, appearing behind. Everytime DispGraph^r is used, the checkered pattern (Reuben Quest-like) for the gray alternates. If it alternates at the right speed, it creates grayscale that is nearly flickerless.

For 4-lv grayscale, you just use DispGraph^rr instead, but the rest of the code is similar. In 4-lv, one of the pic is dark gray and white while the other is light gray and white. Combining light gray with dark gray gives black.