Interesting and unusual uses of teletext

I think your source was me ! I stumbled across a 'burnt in' caption on ITV Oracle in 1984 on an obscure page number. It was obviously put there to be decoded by a teletext decoder 'in line' with the 625 line input of a 625-405 standards converter (that every main 405 line site was fed with) If you can get your head round the idea !

Yep. The Mikefax logo was based on the 1983 Ceefax logo. I upgraded the BBC BASIC software to do all sorts of extras. I recall that Mikefax could only cater for a maximum of three sub-pages - I removed that limitation. My goodness, to think how cutting edge that was in the 80s.

What was Mikefax?

When I was at school we had teletext page design software on our BBC micros. In the 3rd year we all did an RSL in computer literacy and one of those modules was 'viewdata*' -and required making a teletext page.


*viewdata being a teletext via phoneline system, BTs was called Prestel. There was a French system called Minitel and software for that used to appear on the end of some Amstrad CPC games for some reason (the Amstrad was particularly popular in France)

As the short manual puts it: "Mikefax is a simulation of the television companies' teletext system."

It lists its key functions as:

- Set up your own local Viewdata system.
- Cycle up to 93 screens continuously. (NOTE: completely separate from sub-page functionality - Mikefax could only manage a max of 3 sub-pages per page. But the Newsreel facility on page 119 actually physically cycled through pages 103 - 118 - not proper sub-page functionality).
- Construct automatic routing, by linking up pages.
- Edit existing pages.
- Build new pages.
- Download pages from teletext using an adaptor.
- Interface with Prestel using the Acorn Modem.
- Run a mailbox facility on networked systems.

I rewrote chunks of the software so that I could store and edit large volumes of teletext pages from Ceefax and ORACLE. All stored on 5 1/4 inch floppies. I seem to recall there was a limitation on the actual number of files you could store on those discs (a separate issue from disc capacity).

Mikefax was made available to us from a networked hard drive for a few classes at school in the 1980s. During the school holidays, I realised I might be able to do something with the software. Wrote to our education board and they sent me a copy. So I have the original manual. A little nostalgia for those who remember Mikefax:

http://thetvroom.com/tvf/Mikefax-01.jpg
http://thetvroom.com/tvf/Mikefax-02.jpg

I'd have loved that when I was at school.

Our BBC Micro network had a teletext receiver and you could view and print pages from it. I think it could download data from it, but I was there too late for Telesoftware. We had software to create pages but I don't think we could do anything with them except print.

Amazing back then in the late 80s that we had email and could send messages between computers, all on BBC Micro computers. So ahead of their time

We were still using hand cranked calculating machines when I was at school! And we had to share them around the class. How technology has progressed.

How is Presfax delivered to the regions and countries? Is it something like Teletext where the user could control it or is just a static screen sent as a video feed to each region?

To my kids a BBC Micro will seem like a hand cranked machine.

When I left school the Archimedes was just starting to replace them. They seemed so amazing just to have the mouse and cursor, even though they didn't really do much at the time

It's like teletext, sent alongside the vision. To do it as a video feed would take too much bandwidth, There is a feed of the network talkback sent up to the regions too so that is used as well

The cable channels that used to come out of Molinaire in the 80s and 90s, used to put theirs on VBI line 21 I think ?

I believe that it may use inverted signalling.

What vision signal was it being sent with?