Date   : Sun, 07 Sep 2003 13:14:21 +1000
From   : "Bob Devries" <bdevries@...>
Subject: Re: newbie question

Sprow said:
> However,before we go pulling chips out,it's not just something obvious
like
> the H hold or line scan frequency on the monitor?

The monitor is perfectly locked to the picture that's generated.
No jitter, tearing or anything.

> You lot use 50Hz PAL yes?

Yep, that's right.

> As someone else suggests it's probably worth trying the UHF output on a
> normal TV,and also checking (I assume you have a scope) what the H & V
syncs
> are doing and whether they are successfully being mixed by the logic in
the
> video stage,

I've checked the video signal with a scope, and it's correct.

I believe that there's something amiss in th programming of the line size in
the registers of the 6845, or the 6845's access to the ram is faulty.
Without a logic analizer, though, I can't tell.

Regards, Bob Devries