Date   : Wed, 16 Sep 2009 19:41:38 +0100
From   : pete@... (Pete Turnbull)
Subject: No longer Mouldy Beebs

On 16/09/2009 11:39, Rick Murray wrote:

> There were two video chips. Some, and I've only seen these on two issue 
> 3 boards [*], needed a heatsink. The other, I've seen on issue 7 boards 
> [*], didn't. It may be you have the heatsink version. Do you have a 
> heatsink handy? Of if one of your other Beebs has a different video 
> chip, try that instead.

Actually, three.

The original video chip is a Ferranti ULA, which needs a heatsink.
The first VidProc is a VTI chip which doesn't need a heatsink but 
because of a bug in the design, it needs a minor mod to the link that 
normally selects inverse video.
The later VidProc has a slightly different part number and needs neither 
the heatsink nor the mod.

I can't remember the part numbers offhand but I've posted them here on 
the list before.

-- 

Pete                                           Peter Turnbull
                                               Network Manager
                                               University of York