EGA Latched graphics

[tuxie]

Hi. I am making a pretty bodged port of the reverse engineered Cosmos Cosmic Adventure source code (https://github.com/smitelli/cosmore/)

Things are going reasonably well. I managed to wrap my head around how the EGA planar graphics works.

But the latched ega graphics is giving my head some issues. From what I have read, writes to the memory is supposed to be copied across all of the planes. But how does that work? (Example: https://github.com/smitelli/cosmore/blo ... l.asm#L317)

If it copies the same data across all the pages, won't the exact same data be in all the planes, making it effectively black and white? Obviously that's not a thing that happens, so I am.. slightly confused.

Add to that the notion of a 'draw page' that you can see in that source. Are there more than one place you can write graphics data to that you can switch between, or.. ergh. My head :').

Any tips for where to find some non-brainmelting guides for ega graphics, or even some handholding would be pretty nice.

[MrFlibble]

I suggest that you repost your question at VOGONS forums, there's almost no activity here nowadays. Sorry.