This is how far a got trying to show the original Zaxxon graphics  on a TI-99/4A with F18A VDP replacement.     The graphics are using ECM3 mode with 8 colors per pattern or sprite from one of 8 palettes, in a resolution of 224x240 pixels. The first challenge was to display the background, which is using 702 patterns - far more than the 256 patterns available. Luckily no single screen is using more than 251 patterns, which means I could dynamically load the new patt