Just to add ........
I've worked with computers a long time. From Dec system 10 onwards. Through Vaxen, Novas, Eclipses, Honeywell, then up the current distributed systems. Including design, maintenance, and networking.
Best computer ever was the PDP8, which - for first time - gave affordable minicomputing to univerity departments and small businesses (instead of just buying time on larger systems). It set people free!
It had this success, because it gave cheaper timesharing, largely due to the original "filpchip" construction (volume production runs later allowed specialised ICs).http://www.piercefuller.com/collect/pdp8.htmlhttp://en.wikipedia.org/wiki/Flip_chip
(I disagree with Wiki's comments about flipchip! The point was, you could determine if a module had failed, then just get a plug in spare from DEC. Most university scientists knew enough to do this, and it "broke" the far more expensive IBM "business model" for computing. Hence, the PDP8 started the minicomputer revolution!).
Having vast knowledge and experience, across several generations of computers, I thought I was in a good position to answer this enquirey (whatever it was!). That's the only reason i went on, at length. If you don't know what you want
to ask, the best reponse is throw out lots of information.