Date   : Fri, 19 Oct 2007 01:02:52 +0100
From   : pete@... (Pete Turnbull)
Subject: Atoms and video output

On 18/10/2007 16:21, Jules Richardson wrote:

> I've got one though which seems to be running OK, but which has really flakey 
> TV output - once I've tuned the TV  as best I can, the output's still very 
> faint with lots of streaking. (I can just about make out the Acorn Atom 
> banner, and see characters appear on screen in response to keypresses)
> 
> Any ideas what causes this - is it likely a duff (UM1233) modulator? I'm not 
> familiar with the Atom's video chain, but there just doesn't look to be a lot 
> of analogue circuitry upstream of the modulator to go wrong. I've seen beebs 
> exhibit the same symptoms in the past, however...

If the TV is fairly modern, it would be worth trying another TV, if 
possible.  I've had those symptoms with modern TVs where old ones work 
fine, not just with an Atom but with my ZX80 and ZX81s.  Easier than 
changing the modulator, though you might still have to do that.

-- 
Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York