Date   : Sat, 06 Sep 2003 13:42:12 +0100
From   : Sprow <info@...>
Subject: Re: newbie question

In article <001b01c3740d$f9e5f520$0100a8c0@...>,
   Bob Devries <bdevries@...> wrote:
> Further investigation would indicate that the HD6845SP chip may be faulty.
>
> The MA7 output (pin 11) sits permanently at a sort of half-way level,
> neither 0 nor 1.
>
> Now, is there any way I can get a replacement? 

<blatent advert>
http://www.sprow.co.uk/bbc/forsale.htm
</blatent advert>

Chris Richardson at 8BS also probably has some.

However,before we go pulling chips out,it's not just something obvious like
the H hold or line scan frequency on the monitor?
You lot use 50Hz PAL yes?

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,
Sprow.