Roger "Merch" Merchberger asks:
  What was the first portable computer that weighed less
than 1Kg?
 [[I'm assuming that it'd be older than 10 years, so it should be
 ontopic...]] Any pointers appreciated! :-) 
Strictly speaking, the first portable digital computer that weighed
less than 1 kg would have probably been the Gemini Digital Computer,
which was weightless in Earth orbit.  I'm not sure what the mass was,
but it was undoubtedly more than 1 kg.
The first portable digital computer that weighed less than 1 kg on the
Earth's surface was introduced in 1974, and had a mass of just under
0.32 kg.  It was weightless when it was in Earth orbit on the
Apollo-Soyuz Test Project.  Identifying this computer is left as a
challenge to the reader.
Eric