SSE2 vector registers are 128-bit, while CRAY-1 had 4096-bit ones (if I'm reading the manual correctly). Even next-gen AVX will only have 256-bit registers.

Sadly, the part on the instruction set is not available.

Maybe you can find something else that will interest you here: http://www.bitsavers.org/pdf/cray/

Echoing joe_bleau, a scanned PDF of the whole manual can be found at http://bitsavers.org/pdf/cray/2240004C-1977-Cray1.pdf

Could have run Doom, or Quake with a strict asset diet and slightly lower geometry complexity. Of course, that assumes hi color output and some audio.

According to Wikipedia, in 1976 Los Alamos got the first one ... with I'm sure much less polished documentation ^_^.