Date   : Wed, 22 Jul 2009 19:55:39 +0100
From   : zeem.uk@... (Alex Taylor)
Subject: Atom Questions

2009/7/18 Rick Murray <rick@...>:

> Anyway, it might explain why an old computer and a new recorder don't
> like each other.

In the specific case of the ZX81, I've just found some information on
the internet which stated that "the ZX81 video does not have a black
level back porch on the horizontal pulses". I have personal experience
of the effect of this - old TVs (particularly B&W sets) work OK with
it, but modern ones show an unusably dark and distorted picture.

As another example, the Sinclair QL doesn't quite display properly on
a TV or many monitors because it goes right into the overscan area so
the sides of the picture end up being chopped off.

-- 
Alex Taylor