Hi Martin On 26 May 2012, at 13:17, Martin McCormick <[email protected]> wrote:
That is quite okay. I tend to ramble on too long, anyway. Isn't that a problem inherent to most radio amateurs? Perhaps that's why I dislike rubber-stamp QSOs. :) Martin Said: I don't honestly think that the low-speed data transmission capability feature in the video was ever used, here, to it full capabilities. Your version of this particular toy was a lot better than ours. I know that I for one definitely benefitted from it back in the 80s. When I had my second Acorn BBC model B computer, I bought myself a teletext adapter which allowed me to download and decode teletext on to the machine. I wrote a couple of programmes to make the reception of teletext easier. One of which was actually adopted by the manufacturer of the specific type of adapter I was using, as it filled a gap that their programmers hadn't considered. It allowed the user to not only download and display the pages in real time, but also to download and chronologically save the page and all sub-pages on to disk. For instance, the news pages were always indexed at page 100. One item of news would be transmitted as page 100/1, another was 100/2, etc.. Now, if you happened to open the page when 100/120 was being transmitted, it was possible to download the bottom part of a story before you received the first part, as the transmissions were rotated in sequence. So, I wrote a small utility which would look at the page numbers and then the sub-page numbers. It would then look for the first page in the sequence, which always started with "/1". Then it would save that first sub-page to disk and proceed to the second, third and so on until it received the first page over again. Once all pages were saved the programme would assemble the entire sequence for you, remove all unwanted graphics until only the text remained. Then it would offer you the option to either permanently save the page and all of its sub-pages to either individual files or sequentially into one file, or to display the page for you so that you could scroll sequentially through all of the pages in the right order. There were two rival teletext adapters on the market at that time which worked with the BBC model B and the BBC Master. Acorn themselves manufactured one such adapter and the second one, (the one I personally chose to buy) was produced by a company called Morley Electronics based in Wallsend in Northumberland, here in North-East England. Morley asked me if I would object to them distributing my programme, and did so for about a year until the BBC changed the format of their teletext transmissions internally which broke my software. By that time I'd moved on to using a Commodore C64 and so I sent them the raw source for the application which was written in 6502 assembler which you could actually incorporate and run as part of BBC BASIC. Unfortunately, Morley went out of business not long after that time owing to the fact that Acorn bought the rights to their teletext adapter when their chief designer jumped ship. But anyway now it's me who is waffling. Radio Netherlands used to have a weekly short wave program called "Media Network" which dealt with broadcast and media technology around the world and they sometimes mentioned teletext systems in Europe. I remember thinking along the lines of "How Neat!" as one could send any sort of digital data on this channel if it was configured correctly. The BBC World Service had a similar programme actually which was transmitted every Wednesday evening at 23:15 hours, UTC. It was called "World Radio Club", and it was highly useful for those interested in the propagation conditions around the world and the impact they had on radio listening and transmission. Gordon ======================================= The Techno-Chat E-Mail forum is guaranteed malware, spyware, Trojan, virus and worm-free To modify your subscription options, please visit for forum's dedicated web pages located at http://mail.tft-bbs.co.uk/mailman/listinfo/techno-chat You can find an archive of all messages posted to the Techno-Chat group at either of the following websites: http://mail.tft-bbs.co.uk/pipermail/techno-chat/index.html Or: <http://www.mail-archive.com/[email protected]> you may also subscribe to this list via RSS. The feed is at: <http://www.mail-archive.com/[email protected]/maillist.xml> ---------------------------------------
