1 Oct
2008
1 Oct
'08
9:02 p.m.
On Wednesday 01 October 2008 22:58, Jos Dreesen / Marian Capel wrote:
In addition to radio and teletext, there was also a TV
program in Germany
that transmitted software by burying the data in the first few scanlines of
the videosignal. The circuit to recover the datastream was quite simple.
While the broadcast was running you would see a small box in the upperleft
corner where you could actually see the data go by.
I've heard of all sorts of things being stuffed into the "vertical interval"
but that stuff was not ordinarily visible onscreen, unless you fiddled with
the vertical hold adjustment to roll the picture a little, and have the
blanking bar showing.
I've also been curious for some time as to how one could "pick off" a
specific
scan line to get at whatever data was in there, so if that circuit is online
anyplace I'd be interested in taking a look at it, even if it's not
precisely the same thing.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, a critter that can
be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin