Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site sdcrdcf.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!ihnp4!crsp!pesnta!hplabs!sdcrdcf!shaprkg From: shaprkg@sdcrdcf.UUCP (Bob Shapiro) Newsgroups: net.consumers Subject: Re: Cable ready TV, etc. Message-ID: <1684@sdcrdcf.UUCP> Date: Fri, 18-Jan-85 13:41:56 EST Article-I.D.: sdcrdcf.1684 Posted: Fri Jan 18 13:41:56 1985 Date-Received: Mon, 21-Jan-85 02:54:11 EST References: <293@mhuxm.UUCP> <248@terak.UUCP> <282@lsuc.UUCP> <1597@ittvax.UUCP> <712@cbosgd.UUCP> <2640@sdcc3.UUCP> Reply-To: shaprkg@sdcrdcf.UUCP (Bob Shapiro) Organization: System Development Corp. R+D, Santa Monica Lines: 82 Summary: In article <2640@sdcc3.UUCP> brian@sdcc3.UUCP (Brian Kantor) writes: >> if you can buy a cable tuner from Jerrold (the same ones >> the cable company rents you) why is an unscrambler box any different? > >More and more cable companies (especially those serving hi-tech areas >like silicon valley and the like) are going to descramblers which are >digitally addressable. These are individually numbered and can be >individually turned on or off for each scrambled channel by the cable >company. Thus buying a descrambler from a legit manufacturer would gain >you nothing (except saving the monthly rental, if any) because you would >still have to get the cable company to enable it for each scrambled >channel you wanted to watch. > >Of course, a pirate descrambler could be built that ignores the on-off >codes - probably would be cheaper that way too. I haven't seen any at >our local swap meets, but its probably just a matter of time. > I think you will find out that recently almost all cable systems that are installed are either put in with return channels allocated on the cable or a dual cable system which permits bidirectional traffic. The reason for this is that the cable people intend to get into many fields above and beyond the broadcasting of television and many of these require 2-way communication. Examples are home security (which I believe is already in existence in some cable systems), polling of viewer opinions (also implemented in some systems), and even such things as data channels so you can hook up your modem and transfer data at rates considerably faster than what is practical today over standard phone lines. Along with this capability is the ability of the cable company to read your tuner and see what it is set to. Perhaps you might be able to put a second tuner in parallel and they might not be able to tell, but I suspect that if you merely replaced their select box with yours they would know in a big hurry. There are laws on the books which make such actions theft and you might be treated accordingly. Just as an aside I believe cable systems come in 3 flavors. 1. The real old ones use blocks (typically at the pole) to allow only those channels through which you pay for. If you want to cheat you have to climb the pole and remove the blocks. These systems would probably never be 2-way. They have a real advantage to the user in that they permit the user to use the cable with a cable-ready TV and watch pay channels without a descrambler. When you wish to change your pay channel selections then the company must send a person to the pole to redo the blocks. Obviously a slow and expensive process. The disadvantage is that none of the goodies of the future will be available and even current goodies such as the ability to watch special events (boxing matches, 1st run movies, et al) which are pay as you go is usually not available. 2. The next is a tuner which unscrambles those channels which a signal from the host permits it to. This only requires 1-way communication as typically they send out an addressable reset followed by the channels they wish you to watch. The advantages and disadvantages are directly opposite to the above case. Most newer cable systems work this way even if they have a 2-way cable capability. This is because they have only reserved the right for the future but haven't gone to the expense of implementing it yet. 3. Finally the 2-way system which is pretty much as I described above. The problem with playing games with method 2 is that the company can switch to method 3 without your knowledge and you could get caught. As to the scrambling techniques other than the direct block it appears that almost all systems use a form of screwing up the horizontal sync. The sound appears to be untouched. My cable company also has a tuner which is smart enough so that after it senses a couple of seconds of scrambled channel it totally turns the channel off and I see and hear nothing. If I look at the same channel with my cable-ready VCR I can see the distorted picture and the voice is fine. One of the most interesting things that occurs in my system is that if I have side-by-side pay channels (e.g. 43 And 44) and I only have rights to 1 of them I can see a poor reception of the other by adjusting my TV set from its normal channel 3 to either channel 2 or 4 (to go up or down). Apparently the signals slop over the 6mz band. I have often thought about a system which would read one channel and output another. e.g. channel 43 I pay for and 44 I don't. If I could push the cable down 6mz per channel and then feed it into my tuner I might be able to watch 44 instead of 43 even though I told the box it was 43. Obviously the amount to be moved has to be variable and probably in both directions, and it also relies on a principle which I think is true - all channels are scrambled via the same algorithm. Moving 6mz channels around may not be too difficult. After all the box itself moves everything to channel 3. Bob Shapiro