Rotation

After finally getting the SDRAM working (turned out to be a PLL/clock issue) I started to look at screen rotation, given that Namco Classics runs with the monitor in vertical orientation.

There are components in the framework which rotate the video for you, so you don't need to worry about doing it all within the core like I did for all my projects back in the PACE days. It uses the on-board DDR3 as a frame buffer and as a bonus the components that you need to do it also include scan doubler effects such as CRT scan line emulation.

It took quite a while to wrap my head around how it all holds together, modify the design to accommodate the new functionality - which included adding a few more signals out of the YGV608 core - and removing unused signals and code from the project. But eventually I saw this...

Correctly oriented display on HDMI output from MiSTer

It's by no means perfect, and the scan doubler effects don't look right, but I know my video clock is twice what it should be (producing a screen twice as wide as it should be) and there are a few aspects of the MiSTer video framework I'm still unsure of.

Regardless, at least the components are all there so it's just a matter of fixing a few minor issues and I'll have a nice rotated screen to continue with.