[BBC-Micro] Atom Questions

Alex Taylor zeem.uk at googlemail.com
Wed Jul 22 19:55:39 BST 2009

2009/7/18 Rick Murray <rick at rs432.net>:

> 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

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