MRG Systems ATP600 Databridge

My analogue television network is described here, one thing with that set up I have not been happy with was how I supplied the teletext service to the network.  The teletext signal is provided via a Raspberry Pi Vbit-2 server to a dedicated UHF channel not mixed with a programme source signal, as it would have been at the broadcast end, due to me not having a teletext inserter device. This meant non teletext TVs would just see a blank raster, to get over this I forced the Pi server to output a test card image to the console.

As mentioned what I needed was a Teletext inserter, this device takes a teletext feed, in my case the output from the Pi Vbit-2 server, into one of the four teletext inputs. Then supply your main video feed (your programme source) into the device, where it inserts the teletext source into the VBI. Finally, the resulting combined signal is available on the video out port to feed into my distribution network.

Now when you go to any TV in the museum the signal not only contains video but also Teletext, no manual switching required.

The ATP600 DATABRIDGE

The ATP600 is a broadcast quality 6-input databridge and teletext inserter with sophisticated facilities to provide an output teletext service from a mixture of the services being received from the text inputs.

It supports:-

•  Dynamic allocation of lines between services using sophisticated buffering
  techniques.
• Automatic bridging of streamed services without a requirement to define the
  stream configuration.
• Automatic switchover to a standby service in the event of a failure of the main
  service.
• Bridging of subtitles from a number of lines and sources onto a single line on
  the output service.
• Automatic generation of subtitle default pages
• Programming of the subtitle default page
• Generation of time from incoming Network 8/30/1
• Bridging of incoming Network 8/30/1 with NIC replacement
• Automatic generation of 8/30/1 in the event of failure of the incoming service

The ATP600 is a broadcast quality video inserter is contained on the main board capable of inserting on lines 7 to 22 of the VBI. Six teletext decoders are included, each of which can have a plug-in SIS-killer PCB installed. Four have loop-through inputs, and the remaining two may be linked for high impedance or terminated input.

The Hardware

Below are photos of the MRG systems ATP600 Databridge. The 32-pin EPROM used is a 27C010-15, I have taken a dump of this and placed the EPROM .BIN file resides in the Radios-TV data library.