Is a Cub monitor CGA?

for bbc micro/electron hardware, peripherals & programming issues (NOT emulators!)
Post Reply
bleeper
Posts: 123
Joined: Tue May 11, 2010 12:56 pm
Contact:

Is a Cub monitor CGA?

Post by bleeper » Fri Mar 20, 2015 11:58 am

Are the TTL signals in a cub monitor the same as in a CGA monitor? can i just create a cable? I looked at the pinouts but it seems BBC has a single sync whereas CGA has hsync + vsync

User avatar
SarahWalker
Posts: 1190
Joined: Fri Jan 14, 2005 3:56 pm
Contact:

Re: Is a Cub monitor CGA?

Post by SarahWalker » Fri Mar 20, 2015 6:32 pm

Not sure about sync, but I don't think a Cub has an Intensity signal, which CGA uses.

galax
Posts: 103
Joined: Mon Jul 21, 2014 3:58 pm
Contact:

.

Post by galax » Fri Mar 20, 2015 6:35 pm

.
Last edited by galax on Thu Jun 04, 2015 4:42 am, edited 1 time in total.

User avatar
1024MAK
Posts: 9111
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: Is a Cub monitor CGA?

Post by 1024MAK » Fri Mar 20, 2015 7:44 pm

galax wrote:Do you want to put a CGA signal into the CUB? If so you can just combine the hsync and vsync signals (probably best not to just short them together, but that may work).
Don't short them together. You need a logic circuit to do this. On an Atari ST when combining the vertical and horizontal sync signals to drive a RGB to VGA converter (which accepts CGA inputs), an Ex-OR gate is needed.

Mark

bleeper
Posts: 123
Joined: Tue May 11, 2010 12:56 pm
Contact:

Re: Is a Cub monitor CGA?

Post by bleeper » Fri Mar 20, 2015 8:31 pm

Thanks for the replies everyone :-) I was wanting to display CGA into the CUB, (e.g. IBM XT.) I guess it wouldn't be a perfect solution but I have the CUBs to hand already, and find it quite hard to get hold of CGA monitors. Not only that, I love the no-nonsense industrial styling of the Cub. I will look into the Ex-OR gate and see how I get on.

User avatar
1024MAK
Posts: 9111
Joined: Mon Apr 18, 2011 4:46 pm
Location: Looking forward to summer in Somerset, UK...
Contact:

Re: Is a Cub monitor CGA?

Post by 1024MAK » Fri Mar 20, 2015 8:57 pm

The circuit I use with my Atari ST is here.

Mark

bleeper
Posts: 123
Joined: Tue May 11, 2010 12:56 pm
Contact:

Re: Is a Cub monitor CGA?

Post by bleeper » Fri Mar 20, 2015 8:58 pm

1024MAK wrote:The circuit I use with my Atari ST is here.

Mark
Thanks Mark that's fantastic

zeem
Posts: 30
Joined: Thu Mar 12, 2009 10:00 pm
Contact:

Re: Is a Cub monitor CGA?

Post by zeem » Mon Mar 23, 2015 8:25 pm

The Cub monitors were available in various configurations based on the same chassis (there are a couple of different chassis too). The CGA versions have a separate interface board in the back, to handle the 16-colour RGBI signal.

I've got two plastic cased Cubs. One is CGA still, the other I converted to BBC spec by removing the interface board, changing jumpers as appropriate, and replacing the socket on the back with one from a (very) dead metal cased version.

A reverse conversion would be possible with an interface board, but I expect it would be hard to find one.

There are CGA (and Hercules) to VGA converters available too.

Post Reply