BBC Micro

https://github.com/MiSTer-devel/Main_MiSTer/wiki

Moderators: Mug UK, Zorro 2, spiny, Greenious, Sorgelig, Moderator Team

hoglet
Atarian
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Joined: Sat Apr 13, 2013 2:28 pm

Re: BBC Micro

Postby hoglet » Tue Jul 24, 2018 4:15 pm

To run Tube Elite from the SD Card on a real Beeb with the 6502 Co Pro running, the following is used:

Code: Select all

*DIN 45
*TUBEELT

Give that a try?

You can list all the disk images with:

Code: Select all

*DCAT

NML32
Atari Super Hero
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Location: USA/Florida

Re: BBC Micro

Postby NML32 » Tue Jul 24, 2018 8:42 pm

hoglet wrote:To run Tube Elite from the SD Card on a real Beeb with the 6502 Co Pro running, the following is used:

Code: Select all

*DIN 45
*TUBEELT

Give that a try?

You can list all the disk images with:

Code: Select all

*DCAT

Thanks

olin
Atari maniac
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Posts: 90
Joined: Tue Nov 21, 2017 8:57 pm

Re: BBC Micro

Postby olin » Fri Nov 09, 2018 11:32 pm

I just ported BBCMicro core to my de0ns version of MiSTer. One thing I noticed was strong screen flicker caused by the default interlaced mode. I remember that interlaced mode is how the original computer works, so in this respect the core reproduces it perfectly. However my eyes suffer watching the interlaced screen on my TV. Not only that, one of my VGA LCD monitor could not even display such video mode when using scan doubler option and the other VGA flat panel displayed strong simulated flicker as well. I was able to disable it and thought you might find it useful. The mod is very simple, just disable the interlace in the code: mc6845.vhd, line 357, like this

Code: Select all

      --if r08_interlace(0) = '1' then
      --   odd_field <= not odd_field;
      --else
         odd_field <= '1';
      --end if;

basically this mod enables only the odd fields. That's it. Recompile the core and you are done.
Please note I haven't tested this mod extensively, just played a few games, but it seems to work fine so far. It's quite possible some video effects may be lost in certain games, therefore keep your original core if you want to preserve full software compatibility.

Edit: Just thinking about it a bit more, maybe I should have added another option into the menu to disable and enable the interlace...

Sorgelig
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Re: BBC Micro

Postby Sorgelig » Sat Nov 10, 2018 12:32 am

With VIP Scaler there is deinterlacer included. So, on HDMI(main MiSTer video output) there is no flicker.

alanswx
Atari User
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Joined: Sat Nov 25, 2017 4:34 pm

Re: BBC Micro

Postby alanswx » Sun Nov 11, 2018 4:43 am

I saw this posted:

Code for a classic BBC game:
https://github.com/KevEdwards/CrazeeRiderBBC

diggie
Atariator
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Re: BBC Micro

Postby diggie » Tue Nov 13, 2018 4:07 am

Sorgelig wrote:I never had and even never saw this computer in real life.


Thanks for porting this core! The BBC micro was extremely common in UK schools and many kids in the 80s and 90s probably used one to learn programming in BASIC. Certainly these were still doing duty in high schools in Scotland through the 90s.

Dirtbag
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Re: BBC Micro

Postby Dirtbag » Sun Dec 09, 2018 3:57 pm

VGA out on the BBC Micro core has a jiggling effect for me I've captured it here bit can't upload it because of the 500KB limit, but I can share if needed. I don't have this with any other core and it's the same no matter what software I load on the BBC.

olin
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Posts: 90
Joined: Tue Nov 21, 2017 8:57 pm

Re: BBC Micro

Postby olin » Sun Dec 09, 2018 6:57 pm

Dirtbag wrote:VGA out on the BBC Micro core has a jiggling effect for me I've captured it here bit can't upload it because of the 500KB limit, but I can share if needed. I don't have this with any other core and it's the same no matter what software I load on the BBC.

See my post about 5 items above for a partial solution.


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