The original UK digital Ceefax channel transmitted as binary data in the hidden scan lines went off the air with the termination of all analogue TV broadcasting in the UK this week. At one time it had an audience of over 20M but at initial launch there were just 4 decoder boxes in the entire country - all of them wire wrap prototypes.
Though this one is a bit more interesting about the details:
At the time it was ground breaking.
-- Regards, Martin Brown
Martin Brown schrieb:
Hello,
the german equivalent Teletext is still there, it is transmitted over digital TV broadcasting using DVBT too. Analog TV broadcasting over the air ended some years ago.
Bye
Do you guys still use ISDN for telephones?
The little ISDN line transformers are great; I hope people keep making them.
-- John Larkin Highland Technology Inc www.highlandtechnology.com jlarkin at highlandtechnology dot com Precision electronic instrumentation Picosecond-resolution Digital Delay and Pulse generators Custom timing and laser controllers Photonics and fiberoptic TTL data links VME analog, thermocouple, LVDT, synchro, tachometer Multichannel arbitrary waveform generators
I think it is still in theory possible to have one installed even today. And on some extremely long rural lines bonded ISDN with compression will beat ADSL2. There is a village not too far from me where their worst case ADSL download speed is under 128kbps.
They are an experimental region for microwave internet trials.
I suspect ISDN isn't long for this world. I had it once upon a time. They flog it to nervous small businesses using the FUD principle.
I suspect price is per line. You can have ADSL2+ for that. BT kilostream is even more of a ripoff.
-- Regards, Martin Brown
Forget it. I tried to go back to ISDN twice but they simply ignore the order.
-- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico@nctdevpuntnl (punt=.) --------------------------------------------------------------
John Larkin schrieb:
Hello,
ISDN is still used here for wired telephones.
Bye
We still have ISDN running in the People's Republic of Santa Cruz in the form of Pair Gain lines: What happened is that Ma Bell ran out of copper pairs for residential service in some areas, where it was uneconomical to run additional copper. That was usually when it was beyond the range of a T1 (or ISDN/PRI) and they didn't want to install repeaters. So, they multiplex two analog lines using ISDN. As an added detriment, such lines do not support conversion to DSL. I've been fairly successful at unconverting Pair Gain lines back to a single POTS line, and then ordering DSL. However, there is one Pair Gain installation nearby that can't currently be de-converted thanks to a billing issue with the subscriber.
I pull my line xformers from old dialup modems. Some xformers from ISA and PCI computah modem cards work well for various projects (radio to computah interfaces for APRS, PSK31, etc).
-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
All wired phone lines in the US use ISDN. From the very first switch they hit.
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