BBC Micro

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

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

hoglet
Atarian
Atarian
Posts: 4
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
Atari Super Hero
Posts: 592
Joined: Tue Mar 11, 2014 1:54 am
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
Atari maniac
Posts: 91
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
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 3833
Joined: Mon Dec 14, 2015 10:51 am
Location: Russia/Taiwan

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 nerd
Atari nerd
Posts: 44
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
Atariator
Posts: 17
Joined: Thu Apr 27, 2017 4:37 am

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
Retro freak
Retro freak
Posts: 16
Joined: Sat Oct 06, 2018 9:26 pm

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
Atari maniac
Atari maniac
Posts: 91
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.

nico24
Atari freak
Atari freak
Posts: 59
Joined: Fri Aug 11, 2017 5:30 pm

Re: BBC Micro

Postby nico24 » Mon Dec 31, 2018 5:57 am

Is it possible to save anything in this core? Ideally it would be possible to save listings typed in basic back to some sort of storage. For me these cores are about more than just playing old games, but also learning about original programming

Sorgelig
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 3833
Joined: Mon Dec 14, 2015 10:51 am
Location: Russia/Taiwan

Re: BBC Micro

Postby Sorgelig » Mon Dec 31, 2018 8:00 am

Probably, yes.
You need to understand how virtual disk system works in this core. It's done through BBC BIOS extension, so most likely it supports write. In either B or Master mode.

nico24
Atari freak
Atari freak
Posts: 59
Joined: Fri Aug 11, 2017 5:30 pm

Re: BBC Micro

Postby nico24 » Tue Jan 01, 2019 4:23 am

Great thanks Sorg-meister! I'll start investigation.

nico24
Atari freak
Atari freak
Posts: 59
Joined: Fri Aug 11, 2017 5:30 pm

Re: BBC Micro

Postby nico24 » Wed Jan 02, 2019 12:20 am

Ok - after faffing around with it all day, I can confirm that you CAN write to a disk in this core. But it needs to be an MMB file located on a second sd card in the expansion board. The Beeb.mmb file contains 4 virtual disks - below is a short description of some commands to type for navigation:

*. or *CAT - show files on the virtual drive
there are about 512 disks on each drive
*DRIVE X - with the number being 0 to 3 selects one of the 4 disks
*DIN XXX - with number being 0 to 510 selects a disk

You can then use typical commands to save load etc.

If you want to play around with the beeb.mmb file there is a windows executable called MMB Imager that can create and edit them - so you can inject your own SSD disk images into them.

A good day's sleuthing. Thanks to Dave Hoglet for helping out on the Stardot forum.

Sorgelig
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 3833
Joined: Mon Dec 14, 2015 10:51 am
Location: Russia/Taiwan

Re: BBC Micro

Postby Sorgelig » Wed Jan 02, 2019 12:32 am

I think write should work with VHD as well. But since write operation never tested, it might have problems.
Good it works at least with second SD card.

Sorgelig
Fuji Shaped Bastard
Fuji Shaped Bastard
Posts: 3833
Joined: Mon Dec 14, 2015 10:51 am
Location: Russia/Taiwan

Re: BBC Micro

Postby Sorgelig » Wed Jan 02, 2019 12:39 am

By the way, you don't need FAT wrapper for BEEB.MMB. You can use MMB directly. Just rename MMB to VHD and it will work from the primary SD card.
May be this way write will work?

nico24
Atari freak
Atari freak
Posts: 59
Joined: Fri Aug 11, 2017 5:30 pm

Re: BBC Micro

Postby nico24 » Wed Jan 02, 2019 11:12 pm

Just for info I did try it. First you are right the mmb file works if just renamed to vhd, and NO it won't write back to it if it's the primary SD card - it has to be the secondary. Same with the MiST, except the MiST doesn't give the option for a second sd slot.


Return to “MiSTer”

Who is online

Users browsing this forum: knc and 3 guests