Popeye: Early High Res Games (Patreon)

Scralings, one of the director patrons, asked me to look at 1982 Nintendo's Popeye arcade. It looked like an easy game to port. So I accepted... only to find out that this game has the oddest graphics system.

The character layer is pretty much standard, but the background is drawn by the CPU on a RAM chip, pretty much like any 8-bit computer would do. But then, sprites are the most obscure thing I have seen. They use a special clock, at twice the rate of the character layer and the output seems to be interlaced. This means that sprites are actually drawn using a high resolution screen, whereas characters and background are drawn in low resolution. The full effect of this will only be appreciated on a CRT monitor. I still have to think about how to convert this video to a VGA output.

This approach to video didn't actually catch up. Soon after video games stopped using interlaced video with a single base clock for all elements. Popeye shows how engineers were experimenting with different options to create graphic hardware and is a very interesting game from that point of view. But I wonder: are these early games of interest to my patrons?