Re: Analogue Cable Memories
 

Johnny come lately - I was with Jones Cable in Leeds before BCM took them over (I also worked at Jones Cable/BCM/CWC).

Re: Analogue Cable Memories
 

The talkback modules were just a shiny metal box faceplate that fits over the cable input - although - now I think of it - that might actually be a UHF passthrough thing because there was also a cover on the back of the box for slotting a module into.

The ACC-4000 ran SCO Unix according to the instruction manual. It would have had a Motif user interface. The Windows 95 thing you saw was probably a local TV channel that temporarily didn't have powerpoint open to show ads.

Re: Analogue Cable Memories
 

Our Jerrold unit had that metal box tacked on the back. At the time we were using a multi-band, multi-standard TV and it could tune quite a number of the channels separately to the box.

Premium channels used a crude form of "encryption" consisting of inverted sync pulses.

Re: Analogue Cable Memories
 

Re: Analogue Cable Memories
 

When was that Hugh c1932 ? ;)

Re: Analogue Cable Memories
 

1949, sorry, 1994.

Re: Analogue Cable Memories
 

Snap, think we got ours in 1994 or 1995. A salesman came to the door and I bit his hand off I was so keen. Seem to remember there was a bit of an uproar at the time of the cabling project as people said they were killing the trees in my area by damaging the roots (Meanwood back then).
Then when broadband came it was seventh heaven. I remember 200k, there may well have been lower speeds before that but anyway it seemed like witchcraft after the misey of dialup. :D

Re: Analogue Cable Memories
 

@Onramp that seems like a likely scenario. Thanks so much for the info!

@heero_yuy was the encryption/scrambling for premium channels different from standard ones? E.g. would Sky Box Office use a different method from, say, Sky One?

P.S. guys I have an old news report about Milton Keynes and the Virgin/BT cabling dispute. The video is from 2011/12 & features quick clips of a guy changing channels and using menus on his General Instrument box, in good quality. As it's not on YouTube anymore I'll reupload it later/tomorrow and post here.

If anyone has one of these boxes, it'd be amazing if you could capture the menus and interface on direct video capture instead of a camera and put it on YouTube.

Screenshot from video:

I knew 1 cable company (United cable) that scarmabled EVERYTHING (Even non-pay channels) -- I guess they wanted to make sure no one got free service!

Then in the 90s they started unscrambling some of them........

Re: Analogue Cable Memories
 

IIRC there wasn't anything more sophisticated on the NTL cable network as regards encryption.

I do know that Sky went to a more cunning encrytion that at an apparently random point along the TV line the video gets inverted, synch and all. Different point on every line.

The exact point was controlled by a key card and a pseudo random generator and so if you had the key you could decrypt the signal.

Naturally there was a busy black market in cloned and pseudo key cards.

One anti-copying trick that was used on film channels was to insert several lines of peak white during the frame retrace fairly randomly. This is where VCR's set their reference recording levels, as the video here is normally at black level, this would ruin any attempt to record off air.

Most CRT TV's blank this retrace set of lines so the effect wasn't visible on screen.

Incidentally this is why older TV material is 576i and DVDs generally in 576i or 576p rather than 625i. The "missing" lines are the frame retrace period (24.5 lines) needed by the older CRT TVs and other than a few lines being "stolen" to provide the Teletext service contain no video.

Re: Analogue Cable Memories
 

We used to run our digibox through a VCR. We ordered something from on-demand and the picture was just static and black and white grey bars going up the screen like crazy. I'm assuming this is my experience of that even though we weren't copying! I always wondered how that worked, cheers :)

Re: Analogue Cable Memories
 

Since you mention that situation, the old cable cabinet by our exit to the grid road happened to be open the other week, so I had a peek inside to see what was there (didn't touch, of course!)

There was a single yellow fibre optic cable entering a media converter labelled "MK-TV Spine" followed by the spine number. That box had a co-ax cable coming out of it, into a large amplifier and power injector. At the bottom of the cabinet, the two large coax cables had been physically cut. Presumably by BT when VM no longer renewed their lease in 2012 (or whatever happened). There's little to zero chance that network will be reconnected assuming Cityfibre do actually run FTTH in the whole town.

As for the encryption, as far as I remember, the vertical sync signal gets stripped out and placed somewhere in the teletext portion of the signal (vertical blanking interval) in some inverted form. Then, if the box is authorised to do so, it re-inserts the signal. The situation whereby a VHS recorder can't read the signal is named Macrovision, and I think it involves some similar trickery. I'd imagine the Jerrold/GI boxes would output a macrovision protected signal for VCRs.

Re: Analogue Cable Memories
 

Our towns wired ariel was failing and Cambrigde Cable came in and update the entire Ariel network, those that wanted it got cable TV those that didn't just kept the 4 channels (BBC1, BBC2 ITV & Channel 4.)


These went Tit's up and where taken over by the parent company Anglia Cable.


Later NTL the VM.


I remember on CC having both Sports & Movies for £10pm.


But recording went to one channel, that was the channel the box was set too.

Re: Analogue Cable Memories
 

Oh yes, that was the other thing the F button did. You could change the UHF output channel number.

Was it sending out raw digital? (That would produce that on an analogue device)