🚀 go-pugleaf

In article <1992Aug03.174522.27340@bas-a.bcc.ac.uk>, ucjtrjf@ucl.ac.uk (Jonny Farringdon) writes:

[Lots of stuff about saving disks that had been mightly rehashed deleted]

> If one casts ones mind back, when we all had ``home micros'' (z80's &c)
> one recalls that hoovers would Z*A*P them, so sensible micro manufacturers
> would paint the inside of the case with a conducting paint, creating a
> Gauss'ian surface, which incidently *may* have small holes in it.
Like Jonny, my Physics is pretty rusty (and I'm a full time EE undergrad :-)
but I believe that the holes may be as large as half the wavelength of the
incoming electromagnetic wave 
> Computers for the UK government (secrets) have to be treated in this way,
> that's what those fine wire mesh's are over the screen, so that you cant
> pick up any spurious signals from outside the building with your signal-
> detector from Tandys  %-)
AKA Tempest. Though usually they tempest the whole room or building.