[sci.electronics] Cable TV Info wanted!

klby@vax5.CIT.CORNELL.EDU (07/05/89)

Does anybody here know anything about cable TV boxes?

In our area the regular box seems to be a Scientific Atlanta model
8500412.  This cable box is not a simple one like in the old days.
It has what appears to be a CPU and a ROM (256 X 4 I believe) that
allow selective decoding of scrambled signals.

A technical overview of how the system works would be ideal, but
I will settle for having a few questions answered for now.

1) Does the cable company actually transmit instructions to the
   box?
2) If so, does the box ever transmit anything back to the cable co?
3) Is the ROM a unique part or are all the roms with the same basic
   cable service the same?

Thanks for any insight you may have to give me on this!

Matthew Kleinmann