[NJARC] Video Disc Player

[Nick Senker]

I came across and old (1970?) video disc player and some RCA discs.  These appear
to be an enclosed cartidge type (12") which slide into the player.  I guess
this was a foreunner to todays DVDs.  I remember seeing something called 'Laser 
Discs' for sale long ago but they were not encased in a rigid cover like the ones
I have.
I'm curious about the laser technology (?)  used to read/play the discs (were diode lasers
availble then?) and also about the RCA technology/involvment (ALex?).  Are these
of any particular interest to anyone?
Any comments would be of interest.  Nick Senker