The Apple I's onboard video memory was capable of displaying text only. With the addition of the GT-6144 Graphics Board, the Apple I could display primitive black and white graphics.
I saw this graphic board and I don't know if anyone still have a working one wired to his/her Apple 1
but I wanted to try to emulate this graphic board using an Arduino and the TV out library (that can output 128x96 pixels on screen)
You can download the program here: http://onorisoft.free.fr/extern/GT6144.ino
All instructions are included, but it's UNTESTED !
Hopefully, It can emulate the GT-6144 board 64x96 graphics, and I also included a special enhanced mode for 128x96 graphics
I really hope someone can test this until I get my own Replica 1
or even better, if anyone can compare it to a real GT-6144 board, that would be awesome !