Display Problems on BBC Core

[ponder]

Hi.

I've been trying to get some games by Richard "Tricky" Broadhurst running on the BBC Core but 4 of them aren't displaying properly.

I've created a video and a vhd. The video shows the games and problems while the vhd contains the games themselves already set up for easy use.

Does anyone have any ideas? It seems to be down to his smooth scrolling code but I'm not an expert on these things by any means.

The vdh is here: https://home.colinjones.co.uk/files/trickygames.zip (200K).

The web emulator, along with Tricky's games filtered is here: http://www.bbcmicro.co.uk/index.php?rt_ ... oft&sort=b
Most work but these 4 don't.

The video is here:
https://youtu.be/1fWFhJEV8GI

[lamarax]

Welcome!

Have you tried this pack, and then plainly renaming it to .vhd?

From a fellow beeb veteran and enthusiast, hope you succeed in having the core up and running

[ponder]

Thank you

I have a set of perl utils in the BBCMicro folder that I use for vhd manipulation. I'm not having a problem with the core or most programs, just these specific titles (so far). I already have that pack (it was the first one I tried when I first got the MiSTer) and renamed it to boot.vhd but that doesn't contain these titles.

I'm already way past the basics

[zorrobandito]

I'd love to help but I can only replicate the same issue. It would be good to move Tricky's games onto the vhd suggested in this thread and try running them under that configuration to make sure it's not a MISTer Core settings issue but I cannot work out how to mount both vhds to cope them across.

Secondly, I am aware that there were a couple of HDMI display issues with the BBC Core and some games, I believe Elite was a victim but I've tested that and it comes looks fine over HDMI. I think testing over VGA would be a good idea but I don't have an easy option to do this right now.

Thirdly, I tried switching models with little effect on the outcome and adding a maths co-pro causes the game to drop to command line after selecting a control system, so no help there either.

Still, I'm glad you reminded me about Tricky's games because I've been hearing a lot about them on the Ten Pence Arcade Podcast - Victor is a friend and a big fan of his games. I will keep an eye out for a potential solution.

[ponder]

Thanks for checking. I'm still wondering if the same would happen on the real hardware with mmdfs installed. At least I know it's not only me

I tried on VGA last night but it's exactly the same.

I just tried that image, it's not quite the same as the one I already had but had the same menu. Some of Tricky's games are there but still behave the same.

When I got the MiSTer and tried Elite that issue was already fixed so happy about that

[ponder]

Some words from Richard Broadhurst to aid in the hunt for a solution:

I'm happy to help however I can. Scramble looks like a 6845/vsync interrupt timing issue, which will affect the others too. Canyon bomber looks like the same issue plus maybe having the video ula mapped to more than just fe20/21. Canyon bomber also supports video NuLA. Try frogger, if that has similar palette issues, it is probably the ula mapping, plus not handing unexpected inputs.

For the record, Frogger works fine.

Frogger uses a slightly different screen setup that allows for a little more slop on the vsync/6845 register latching/comparing. I don't see how Astro Blaster could have the edges of the control pannel nearly touching, when they are as far apart as the visible part CRT timing was. Likewise, Phoenix, could it be missing the hsync for them?

[MiSTer_Kirk]

They all work fine on real hardware. I have tried them with my BBC Master 128k, ADFS, and an external Gotek Drive with the Flash Floppy firmware.
My Master is fully modded out with a 4-way switchable Multi OS, Raspberry Pi Multi-Core Co-Processor, RetroClinic Compact Flash drive, and the Flash Floppy Drive - so it's not a stock BBC.

[ponder]

Thank you MiSTer_Kirk. I'm pretty new to MiSTer and learning fast but the creation and update of the cores themselves will always remain a mystery. Hopefully this can point those who know what they're doing to find and fix these issues which can only improve this incredible core.

[MiSTer_Kirk]

The only issue with this BBC core is the lack of floppy drive support, so no loading of .ssd or .dsd disk images.
The BEEB.MMB format is a convoluted way of using a BBC Micro. On a real BBC B, the BEEB.MMB format is an older way of using modern sdcards on the BBC. Thankfully, we now have Gotek Flashfloppy drives, or Retroclinic USB harddrives.

[ponder]

Just updated to the new core, no difference.