EclaireXL

I fixed the dma clock, then I found character fetching was not working either. I've fixed that for 2x, but still remains broken for 4x. Doing a build to see if I'm right on 2x:-)

Fixed a few more bugs and tried it again. Was starting to despair that it worked on sim but not the real hardware. Then I selected 2x CPU mode - and it worked! Of course I'm blocking most of the cycle to wait for PBI in 1x mode, doh. So there is no possibility of accessing the ram so fast there.

There are some more bugs to squash but looking promising. Notably characters are missing over refresh cycles (again blocking data/character fetch) and I also need to sort out hscrol dma clock delays to by smaller. Also I need to fix an acid test or two...

iirc sdram refresh takes about 1/2 cycle, so far too long to allow during video dma at 2x or 4x. So will have to move that offscreen I guess in these modes.

Sped up the refresh cycles to 2x and 4x. No missing characters now mid-screen. However this will probably flicker on SDRAM, since its shorter than a real refresh cycle iirc.

Took a look at hscrol. Understand what needs doing but too tired now. Built an example core for anyone who wants to play with it in the meantime. For v1 and v2.

Fixed issue with sprites - I had changed hscrol to count at 4x original colour clock and forgot to adjust the dma address by 2 bits as well.
Made hscrol work as a colour clock delay, which should fix highres scrolling.

Thinking about this I bet I just broke the hscrol change delay, since this will no longer allow late changes. One to think about...

Back to computing the dma clock start cycle, rather than applying hscrol high bits as a delay. With 2x and 4x support still though.
Next up, need to sort out the output timing to be aligned with the displayed area... Then onto some gtia fixes and checking out what is up with 32x sprites etc.

I added rendering of the video output ot the test bench... Very helpful to debug visual video issues.

Keep up the good work, thank you for all the time you are putting into this!

I think I have the antic alignment all working. Next up, gtia...

gr.8 seems to be off by half a colour clock in 4x mode. Wonder if that is gtia or antic. Didn't notice that in gr.0

Hoping to get back to being able to test out this new stuff real soon! I'm finally finishing up a major vehicle repair which has been keeping my tied up since mid April. I'll have it back on the road by end of day tomorrow.

Added a many modes at once screen (antic 8 through antic f for now) to debug in 1x,2x and 4x. I don't see the half colour clock shift in gr8, perhaps I was mistaken when looking on the TV. I am seeing some stripes in some low res modes in 2x, which was a bug I had a few years ago in these modes.

Fixed the mode 8 stripes in 2x bug. Tricky to debug, one line fix!
Added gtia greyscale mode to the testbench. This isn't working properly in 2x and 4x - getting strange stripes. I guess the wrong clock is used in gtia somewhere. Will be easier to debug now I can see it:-)

Fixed gtia modes in 2x and 4x. Also fixed oddline flag (needed for svideo pal).

Working on PMGs. These will still be the original resolution. I found some issues with them related to the resyncing of the antic and gtia logic - this was the root cause of the oddline flag issue last looks somewhat fiddly to fix. Getting there!

So antic output looks near perfect. Some blue blobs on the left which I need to investiate. The shift register is clear so not sure where they come from!

Sorry - been away far too long. I have not unpacked my Eclaire since I got back from VCFMW in 2017. I am preparing for this show in 2019, so I am all updated to core 31. I'll be looking into the 2X and 4X ANTIC modes more over the next few weeks.

xxl might be making his E: and S: driver work in high res, I hope. Please :-)