Rick's b.log - entry 2018/08/26

Minitel online!

Astonishingly, it worked!

I think it is using standard MODE7 style block graphics for the picture, but the way it does it makes it look better than stuff I've seen on teletext (or viewdata). I recall that Minitel must work in text or graphics mode, as it tends to draw the graphics and then go back and do the text afterwards. Here is another service I called:

Now to reply to some comments by David Pilling:

"Is there a Minitel legacy, some place on the web where one can connect to a Minitel source,". I have found Jelora (who built his own system from the ground up) and JCA (that I think is running it on a Mac of some kind?). I don't imagine there are going to be many services. These days, a monochrome system running at 1200/75 is going to be more a labour of love than anything else, much like those who keep steam engines running.

"can't believe they chucked the lot". I can, sadly. It might have been seen as more expensive to purge the equipment of user data, or maybe all storage was removed and destroyed (leading to what's basically a bunch of possibly OS-less machines and ancient modems). Scans of some of the technical documentation has made it into the wild - search for "stum1b" (~55MB PDF) if you're interested.

"Anyway if there is, you'll be able to test your terminal, and... compare it with the Hearsay emulation." I managed to test the terminal, and it seemed "okay", though one of the problems that I am sure I'm going to run into is the extremely eccentric keyboard layout. Here's a picture of it from the technical guide (the red markings are pointing out the different parts of the keyboard):

"some of the subtleties of French pages were going to escape us. Oddly way back then, no one had test suites, "see if your terminal will pass these tests"."
There's the thing. The character sets. American mode offers different characters to French mode, and it looks like it is possible to switch in different characters. Does Hearsay support that? How about status reporting? In the technical manual, part 2 chapter 2 describes some of this behaviour.
Test suites? I think a lot of these things grew organically. I recall discussing with you Hearsay's ANSI terminal behaviour regarding whether to perform a newline upon reaching the end of a line, or when passing beyond the end of the line. I think the latter is more logical. Hearsay, IIRC, does the former. As do DEC terminals if the DEC VT100 guide is anything to go by. But not others. Test suite? ☺

"I suppose VT100 begat ANSI, which was a standard." Yes, ANSI is basically VT102 with colour. But, no, it's only partially a standard - some of the things like low intensity, blinking, underline, and invisible are implemented in different ways; and alternative character sets and double height/width may not be supported at all. For example, Hearsay supports rapid blick (ESC[6m), and codes in the range 22-27 to turn effects off individually. Is this "standard", as it seems to vary, as does the colour capabilities (eight dim/bright or 216 colours, or 16 level greyscale...). There are also codes for strike-through and Fraktur (!) font support, for maybe the one terminal that actually supports such a thing.
And what's Windows' HyperTerm's "ANSIW" supposed to be?

"As ISTR we had dealings about this, for Hearsay I tacked colour codes onto VT <whatever>." Looking at the CSI documentation (that's Control Sequence Introducer, not Crime Scene Investigation!), it looks like ANSI is basically exactly that. VT-blah with colour and stuff bolted on.

"Why they not do Minitel over telnet like Arcade." The service closed in 2012. I guess by then there were better more attractive services. The browser wars were over, HTML was fairly advanced, and the French government had realised that encryption is necessary for e-commerce. Seriously - every time I took my RISC OS machine with SSL and PGP to France with me, I may have technically been breaking the law. It wasn't until 1999 that France looked to permit personal use of encryption technologies, something they are now complaining about due to the terrorist events of recent years (despite no evidence of such technologies being a contributing factor). Anyway, France was "modern" by 2012 and even had broadband rolled out to nowhere places like, well, here. So the switch off of Minitel meant a transition to new technologies.
The reason Arcade is widely supported is because, unlike Minitel, the protocol that Arcade uses is basically the same as that used for remote administration of servers, and command line access via the dumb terminal. It's an old protocol, but extremely widely supported.

All this being said, I'm not planning to use the Minitel as a Minitel. I'm likely to use it as a VT100 terminal for debugging.

Your comments:

Please note that while I check this page every so often, I am not able to control what users write; therefore I disclaim all liability for unpleasant and/or infringing and/or defamatory material. Undesired content will be removed as soon as it is noticed. By leaving a comment, you agree not to post material that is illegal or in bad taste, and you should be aware that the time and your IP address are both recorded, should it be necessary to find out who you are. Oh, and don't bother trying to inline HTML. I'm not that stupid! ☺ ADDING COMMENTS DOES NOT WORK IF READING TRANSLATED VERSIONS.
 
You can now follow comment additions with the comment RSS feed. This is distinct from the b.log RSS feed, so you can subscribe to one or both as you wish.

David Pilling, 29th August 2018, 22:10

Hearsay was intended to record stuff, it had spool files, binary streams and frame files for Viewdata (let you take a copy of the screen contents (as text)). I suspect dedicated terminals would not be so oriented. Anyway on the Hearsay Extras disc (which I guess is part of the current free download) there is a Minitel spool file you can replay. (Shift drag into Minitel terminal, then click on Continue on the replay gadget to step through the pages). Apparently the last fragment of a lost culture.

David Pilling, 29th August 2018, 22:19

It is on this URL:  https://www.davidpilling.com/hearsay.zip  rather than the source code one.  For Viewdata there were numerous pieces of editing software, so a lot of viewdata pages must still exist on anything from BBC to PC discs. I'd expect the same to be true of Minitel.

David Pilling, 29th August 2018, 22:24

I guess I had a Minitel spec. but as I recall it was difficult to make sense of. ISTR reverse engineering Minitel, then getting the spec. and finding it worked in a completely different way to how I had done it. And the false way got 99% right, but to get 100% I had to rewrite it properly. Don't recall US character support, but the source code for Hearsay Minitel is on my website and you can see what I hath wrought.

Rick, 29th August 2018, 23:45

Uh, I think I'll pass. The spec is indeed difficult (it's in French and it seems to use some terms a little differently to normal English use, not to mention overcomplicating things (it would NOT have killed them to call the téléinformatique mode a VT100 terminal!)). Like you say, your implementation may be 99% correct, with that elusive needle in the haystack to try to find. If Minitel was a thing and we could hit it with live pages, then maybe. But since it's a relic, let's let bygones be bygones, eh?    US character support - that's American mode vs French mode, described using complex things like C0 and C1 characters (or something like that). I'm not entirely sure if Minitel can run in American mode, or if it's only the VT100 that does it.  And, since you're the comms expert around here, what's this X25 PAD stuff? Something about it in the tech guide...

Rick, 29th August 2018, 23:50

Follow up - looks like Minitel itself was one of the last consumer uses of the X25 network system (it's a packet switched wide area network service (a little like Internet Protocol) that worked on normal phone lines and was popular before the world knew what the internet was.

Rick, 29th August 2018, 23:53

Arguably, France had a huge publicly accessible network and a *majority* of people online before most people outside of academia even knew what those terms meant.

David Pilling, 30th August 2018, 03:11

What is X25 PAD? No idea, Google it. But I suspect I used it once. To get on to Minitel there was some horribly complex system. There was something like a "packet switch system", oddly the nearest phone to access it was in a small village 50 miles away. You had to type in commands, a bit like modem AT commands.  My Minitel implementation is 100% right, I had no complaints ;-)  With Hearsay having a VT emulator as well as Viewdata (etc). I now dimly recall commands for switching between the two. They definitely exist for things like Tektronix emulation, but yes, for viewdata too.

David Pilling, 30th August 2018, 13:23

Few more memories... there were other Minitel emulations on RISC OS (all those schools). Seem to think I used to look how good the others got their emulations. I never saw Peter Gaunt's "Arccomm" though. Again all those schools they were not dialling France direct, presumably on the PSS (packet switch system) like me. So somewhere a gateway between Minitel and PSS. Yeah which system needed VT100 and Viewdata - Acorn had a Viewdata system "SID" (like in Space 1999) - you can sort of see that a company like Acorn needed an internet presence to support (ha!) users. I think somewhere there is a dump of a file server, which is about as far as it got before 1998.

Rick, 30th August 2018, 14:28

Hmmm, now where could there possibly be a big X.25 network in the UK in the late 80s/early 90s?  How about JANET?

David Pilling, 30th August 2018, 22:27

https://en.wikipedia.org/wiki/Packet_Switch_Stream is interesting, BT owned Packet Switch Stream, set up in 1981, lasted (incredibly) until 2006. X25 based. Glory days 1990 (just before consumer internet took off).

David Pilling, 13th September 2018, 01:54

I read that there are people who have devised a way of extracting Teletext from old video recordings (unless your video is very good this does not normally work) and the aim is to preserve historic information.

David Pilling, 13th September 2018, 13:44

The system that combined Prestel with a text terminal was called "Campus 2000" - you can Google it and find articles "the development of the Prestel and TTNS systems of videotext and how they have come together to produce the Campus 2000 System which is becoming increasingly important in UK educational systems"

Christian Berger, 14th September 2018, 22:54

I've actually been experimenting with the German Minitel variant.   My experiments are here https://github.com/Casandro/cas_btx/    I'm actually thinking of a more modern protocol which can be translated to Minitel or Bildschirmtext or Prestel, but offer a wider range of Videotex features with support for UTF-8.    There are now various V.23 modems for Asterisk available, BTW.

Add a comment (v0.11) [help?] . . . try the comment feed!
		Your name
		Your email	(optional)
		Validation	Are you real? Please type 37136 backwards.
		Your comment