Craig,

16 colors requires 4 bits per pixel @ 640 pixels per row thats (4x640)/8 bytes per line (320 bytes). Providing 480 rows results in 153,600 bytes per frame.

According to the web the ATARI 800 was 24 X 40 text, @ 320 x 192 monochrome and 160 x 96 with 128 colors. So 7 bits per pixel (6 bits + Intensity?) (7x160)/8 = 140 bytes per line so a frame of 96 lines was 13,440 bytes.

So the decision point now moves beyond whether a VGA Monitor is the display target, you can use them as long as you generate the appropriate H-Sync/V-Sync but now to what pixel rate you can support between these points and the depth of memory.

This is what the previously cited VGA/Ping Pong TV designs do, they generate the approp. sync and then jam as many pixels as they can with whats ever left for the platform of choice.

regards,
p