Oric V23 Modem

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Dbug
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Re: Oric V23 Modem

Post by Dbug »

iss wrote:
Sun Feb 07, 2021 12:58 am
You can start shorting only TX and RX to see if the typed characters will be echoed back, if not then do other connections.
(...)
OTRM is hard coded for 9600 baud, 8 data bits, 1 stop bit, no parity, DTR=0, RTS=1
So, my "new" terminal, the Magis Club, does has a 9600 bauds, 8 data bits mode, and I can actually see what I type on the Oric on the minitel (when I set it up in this mode), but typing on the Minitel keyboard does not seem to send anything to Oric Term 380, so I did your TX-RX strap, and all I'm typing his appearing on the Oric, so I guess that means the Receive pin is properly identified and working.
image_2021-04-19_193014.png
image_2021-04-19_192950.png
image_2021-04-19_193036.png
image_2021-04-19_193111.png
So, just to be back in context, here are the connections I had identified on the Oric RS232 interface:
1 - Black - DCD -> 7
2 - RED - TxD -> 2
3 - Green - RTS -> 4
4 - Orange - GND -> 3
5 - Blue - DTR -> 6
6 - White - RxD -> 5
7 - Brown - RxC -> 1
8 - Copper - GND -> Shield

and how I wired these to the DB-9 connector:
+--------- (Red) 1 - DCD -> Oric 1: Black [Data Carrier Detect]
| +------- (Black) 2 - RX -> Oric 6: White [Received Data]
| | +----- (Gray) 3 - TX -> Oric 2: Red [Transmitted Data]
| | | +--- (Orange) 4 - DTR -> Oric 5: Blue [Data Terminal Ready]
| | | | +- (Brown) 5 - GND -> Oric 4: Orange / Oric: 8 Copper
| | | | |
1 2 3 4 5
6 7 8 9
| | | |
| | | +-- (Yellow) 9 - RI -> Oric ??? [Ring Indicator]
| | +---- (Blue) 8 - CTS -> Oric ??? [Clear to Send]
| +------ (White) 7 - RTS -> Oric 3: Green [Request to Send]
+-------- (Green) 6 - DSR -> Oric ??? [Data Set Ready]

I did not connect RI, RTS and DSR, because I had no idea what they should connect to on the 7 different wires (4 and 8 are both ground) of the Oric interface.

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Re: Oric V23 Modem

Post by iss »

Since yesterday I'm reading lot of info (in French :shock: ) trying to understand two things:
what's actually the Minitel-terminal and what's the point to connect it to Oric :).

Here some useful links (probably you know them already):
- https://fr.wikipedia.org/wiki/Micro-serveur_Minitel (note Oric/Telestrat in the table)
- https://spectrum.ieee.org/geek-life/han ... l-terminal
- http://hxc2001.free.fr/minitel/index.html (Cool!)
- https://www.jelora.fr/post/2017/08/27/S ... nitel.html (Great!)

From what I've understood and according to these links:
- https://chapelierfou.org/blog/a-minitel-2.0.html
- https://chapelierfou.org/blog/a-minitel ... minal.html
- https://pila.fr/wordpress/?p=361

I think that you need to connect only 3 wires between Oric and Minitel: Rx->Tx, Tx->Rx and GND
but there should be kind of voltage level converter.

A side note not related to this topic: The only purpose of the ugly Telestrat's telephone wire is to provide IRQ on incomming ring :).

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Re: Oric V23 Modem

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iss wrote:
Tue Apr 20, 2021 9:46 pm
Since yesterday I'm reading lot of info (in French :shock: ) trying to understand two things:
what's actually the Minitel-terminal and what's the point to connect it to Oric :).
That's a fair question.

It all started on the fact that most people outside France has never seen the Minitel and what it could do, and the fact that the one single thing the Telestrat was good for was to be a cheap minitel server hardware, and also things like Loritel which allowed you to attach your Oric to the Minitel, and use it to store information pages, print them out, and even also make a miniature minitel server machine.

Since most analog servers are gone, and some people have been maintaining some minitel and prestel servers, which can be accessed through VoIP adapter, I just wanted to bring back the experience, and make a video about it, connecting to a Telestrat minitel server from another minitel with Loritel connected to it, and also show that with the Oric V23 modem you can also connect to Telstar's Prestel service in the UK using the Tansoft Prestel software.

So that's for the orig story.

Now, by poking around, I found out that my minitel had a perfectly usable 80 column mode, and if I can get the RS232 connection to work both way, I could use that screen and keyboard as an external debugger, memory viewer, etc... or connected to the PC send files directly to the Oric instead of swapping USB and SD cards.
iss wrote:
Tue Apr 20, 2021 9:46 pm
Here some useful links (probably you know them already):
I'll check that later, but I recognize most of them :)
iss wrote:
Tue Apr 20, 2021 9:46 pm
I think that you need to connect only 3 wires between Oric and Minitel: Rx->Tx, Tx->Rx and GND
but there should be kind of voltage level converter.
Hmm, that does not explain why I can see on the Minitel what I type on the Oric, but not the other way around.
iss wrote:
Tue Apr 20, 2021 9:46 pm
A side note not related to this topic: The only purpose of the ugly Telestrat's telephone wire is to provide IRQ on incomming ring :).
Yes, ring detection, so the Telestrat can automatically take the line when a call is detected,

Personally I plan on removing the fixed cable and install a female RJ11 connector on the back, that would serve the same purpose and not get in the way when not needing it.

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Re: Oric V23 Modem

Post by jbperin »

Did you try this configuration ?
NoMoreMinitel.jpg
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Re: Oric V23 Modem

Post by Dbug »

jbperin wrote:
Wed Apr 21, 2021 8:02 am
Did you try this configuration ?
NoMoreMinitel.jpg
Other than the fact you consider that the high point of French network technology from the 80ies is worth putting in the trashcan, which I consider totally not funny despite the effort spent doing the drawing, I think you also missed the fact that the minitel was also an actual perfectly usable modem that you can use to have two oric talk together, or exchange files, without the need of a PC.

Based on your suggestion, I think we should just throw the Microdisc since we have the cumana reborn, burn all the tapes since we have erebus, destroy the crt screens since we have flat screens, and then probably blow torch all the orics since we have emulators on our pcs.

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Re: Oric V23 Modem

Post by jbperin »

Dbug wrote:
Wed Apr 21, 2021 8:12 am
Other than the fact you consider that the high point of French network technology from the 80ies is worth putting in the trashcan.which I consider totally not funny despite the effort spent doing the drawing,
Il y avait une pointe d'humour provocateur dans ce dessin et je vois qu'elle a fait mouche.

Concernant le point culminant de la technologie réseau française des années 80, personnellement je parlerai plus volontier de X.25 Transpac que du minitel. Mais bon .. c'est chacun ses goûts .. et sa perception.

Un minitel ne doit évidemment pas aller dans une poubelle. C'est un bel objet à collectionner.
J'ai un collègue qui l'a récemment utilisé comme terminal série pour commniquer avec un arduino sur un projet .. avant de découvrir le câble USB / série.
Dbug wrote:
Wed Apr 21, 2021 8:12 am
I think you also missed the fact that the minitel was also an actual perfectly usable modem that you can use to have two oric talk together, or exchange files, without the need of a PC.
J'avoue avoir totalement oublié cet aspect là du bastringue.
Et je ne me rappelle pas avoir vu beaucoup de personne utiliser le minitel de cette façon là.
Peut-être que Luc l'avait fait mais je ne suis même plus certain.
En tout cas c'est balaise d'essayer de raviver cette technologie à travers un cas d'usage qui, déjà à la "glorieuse" époque du minitel, n'était pas largement maîtrisé.
Dbug wrote:
Wed Apr 21, 2021 8:12 am
Based on your suggestion, I think we should just throw the Microdisc since we have the cumana reborn, burn all the tapes since we have erebus, destroy the crt screens since we have flat screens, and then probably blow torch all the orics since we have emulators on our pcs.
:shock:
You can do what you want with your own gear.
But please be sure that I won't endorse any responsibility for whatever damage occurs following this misleading interpretation of my post.

Tu fais ce que tu veux avec ton matériel mais inutile d'essayer de me mettre ça sur le dos.
Je tiens à me désolidariser totalement de cette interprétation délirante de mon post.

Moi ma queston était plutôt du genre : "Es-tu déjà parvenu à envoyer des données par un lien série depuis un PC vers l'Oric?"

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Re: Oric V23 Modem

Post by Dbug »

jbperin wrote:
Wed Apr 21, 2021 12:24 pm
Moi ma queston était plutôt du genre : "Es-tu déjà parvenu à envoyer des données par un lien série depuis un PC vers l'Oric?"
And as I already told you yesterday on IRC, I have to find my null modem cable.
En tout cas c'est balaise d'essayer de raviver cette technologie à travers un cas d'usage qui, déjà à la "glorieuse" époque du minitel, n'était pas largement maîtrisé.
This was used by many people, you just did not happen to know them.
I was routinely using a minitel to send builds of my Atari Falcon 030 painting program to a friend in another city, because that was much faster than using floppies sent through the post.

Anyway, to be back to the minitel, your original message, funny or not, was totally out of place because the whole point of what we are doing on Defence Force, is to have fun with old technology, and my own work, with Oriclopedia, etc... is to document and show how these things worked, and the minitel was a part of it, so it has to be documented.

You can't possibly talk of the Telestrat without considering the minitel, that was the only unique selling point for the machine.

And I don't see how I can present Loritel without a minitel either.
Concernant le point culminant de la technologie réseau française des années 80, personnellement je parlerai plus volontier de X.25 Transpac que du minitel. Mais bon .. c'est chacun ses goûts .. et sa perception
I suggest you read the book "Minitel: Welcome to the Internet", of course Transpac was great, after all it was the backbone on which the entire system was based on. I was not referring to the actual hardware, I was referring to the impact of this technology on the society: British had Prestel, which was very similar technically, but it never approached the universality of what minitel did, in the 80ies it was common for people to use the minitel to find people in the white pages, consult their bank accounts or order train tickets.

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Re: Oric V23 Modem

Post by Chema »

Dbug wrote:
Mon Apr 19, 2021 6:34 pm

So, just to be back in context, here are the connections I had identified on the Oric RS232 interface:
1 - Black - DCD -> 7
2 - RED - TxD -> 2
3 - Green - RTS -> 4
4 - Orange - GND -> 3
5 - Blue - DTR -> 6
6 - White - RxD -> 5
7 - Brown - RxC -> 1
8 - Copper - GND -> Shield

and how I wired these to the DB-9 connector:
+--------- (Red) 1 - DCD -> Oric 1: Black [Data Carrier Detect]
| +------- (Black) 2 - RX -> Oric 6: White [Received Data]
| | +----- (Gray) 3 - TX -> Oric 2: Red [Transmitted Data]
| | | +--- (Orange) 4 - DTR -> Oric 5: Blue [Data Terminal Ready]
| | | | +- (Brown) 5 - GND -> Oric 4: Orange / Oric: 8 Copper
| | | | |
1 2 3 4 5
6 7 8 9
| | | |
| | | +-- (Yellow) 9 - RI -> Oric ??? [Ring Indicator]
| | +---- (Blue) 8 - CTS -> Oric ??? [Clear to Send]
| +------ (White) 7 - RTS -> Oric 3: Green [Request to Send]
+-------- (Green) 6 - DSR -> Oric ??? [Data Set Ready]

I did not connect RI, RTS and DSR, because I had no idea what they should connect to on the 7 different wires (4 and 8 are both ground) of the Oric interface.
I'm afraid I cannot be of much help here. I used RS232 in the past and, when using hardware handshake signals, we crossed the RTS & CTS lines. I did not understand quite well your connection explanations (I confess I did not review the rest of the posts and your videos to clarify), but the fact that you have unconnected RI, RTS and DSR may be the issue here (in your text above I thought you had RI, CTS and DSR unconnected, though). The minitel/modem may not be sending anything to your Oric as your RTS or CTS is not asserted.

I always get confused about the different versions of the RS232 norm for these lines, but I guess if RTS is not connected, the Oric might not be granting permission to the modem to send the Oric anything. I think DSR is not that important, as it serves to indicate the modem is ready.

But I am sure you already knew all this and tested things... I am curious, though... is this RS232 interface following the voltages in the original RS232 (+-15), or does it use lower voltages (+-5)? Also remember 0 volt does mean neither mark nor space.

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Re: Oric V23 Modem

Post by jbperin »

Dbug wrote:
Wed Apr 21, 2021 12:46 pm
Anyway, to be back to the minitel, your original message, funny or not, was totally out of place because the whole point of what we are doing on Defence Force, is to have fun with old technology, and my own work, with Oriclopedia, etc... is to document and show how these things worked, and the minitel was a part of it, so it has to be documented.
Sorry but wanting to have fun with old technology does not prevent anyone from having methodology.

You're trying to set up a full duplex serial communication between two equipments.
You managed to get one half-duplex and failed to have the other half-duplex working.
Then I'm questioning you to know if you have already or if you can set up this failing half-duplex by an other mean.
The goal is to see if this half-duplex works in an other context. And eventually identify the difference between the failing context and the working one.
Funny or not, I still consider my original message was one of the best question I could ask you.

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Re: Oric V23 Modem

Post by Dbug »

jbperin wrote:
Thu Apr 22, 2021 7:12 am
Dbug wrote:
Wed Apr 21, 2021 12:46 pm
Anyway, to be back to the minitel, your original message, funny or not, was totally out of place because the whole point of what we are doing on Defence Force, is to have fun with old technology, and my own work, with Oriclopedia, etc... is to document and show how these things worked, and the minitel was a part of it, so it has to be documented.
Sorry but wanting to have fun with old technology does not prevent anyone from having methodology.

You're trying to set up a full duplex serial communication between two equipments.
You managed to get one half-duplex and failed to have the other half-duplex working.
Then I'm questioning you to know if you have already or if you can set up this failing half-duplex by an other mean.
The goal is to see if this half-duplex works in an other context. And eventually identify the difference between the failing context and the working one.
Funny or not, I still consider my original message was one of the best question I could ask you.
Yes I know I need to test with other devices, which is why I told you (for the third time now) that I need a null modem cable, and I wrote that before you even made the suggestion.

All I'm saying is that the joke about throwing the minitel was not fun to me.

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Re: Oric V23 Modem

Post by Chema »

Back to the topic and to my post :)

I am sure you tried, but it makes no harm to ask... Did you try to feed +5 or -5 volts (to set mark or space) into CTS (and/or DSR)? It might be just a problem with the Oric side not signaling that the other side can transmit data...

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Re: Oric V23 Modem

Post by Dbug »

Chema wrote:
Thu Apr 29, 2021 12:35 pm
Back to the topic and to my post :)

I am sure you tried, but it makes no harm to ask... Did you try to feed +5 or -5 volts (to set mark or space) into CTS (and/or DSR)? It might be just a problem with the Oric side not signaling that the other side can transmit data...
Nope, I've not, I'm still waiting for my null modem cable.
There does not seem to be any +5 volt on the RS232, so I guess I would have to somewhat get it from the Oric

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Re: Oric V23 Modem

Post by Dbug »

So, I finally got my null modem cable, and when I try to talk between my PC and the Oric (Using 9600 bauds, 8 data bits, 1 stop bit, parity none) what happens is that what I type on the Oric keyboard appears on the PC (tested with both PuTTY and Termite), but what I type on the PC is weird, it's like only one key press every two was received, or sometimes the first character is correct, the second is incorrect (or missing) and the third one is correct.

On these tools, for flow control all I have is none, RTS/CTS, DSR/DTR, XON/XOFF, but that does not seem to change much.

Any idea on what is misbehaving on my connections?

Should I just get this +5 signal from somewhere to CTS and or DSR as suggested by Chema?

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Re: Oric V23 Modem

Post by iss »

OTRM is never tested with real hardware, so it's very plausible that it's buggy.
Did you tried ORICOMMS? IIRC it provides a setup for port and some settings at startup :idea:
Dbug wrote:
Fri Apr 30, 2021 6:28 pm
Should I just get this +5 signal from somewhere to CTS and or DSR as suggested by Chema?
I really don't understand this idea ?! If this is to permanently activate (for instance) CTS - you should feed minus 5V relative to GND and disconnect the other side which sends RTS

EDIT: Feeding external voltage is actually the same as to make a local loopbacks:
D9_Null_Modem_Wiring.png
signal.
Last edited by iss on Fri Apr 30, 2021 7:12 pm, edited 1 time in total.

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Re: Oric V23 Modem

Post by Chema »

In null modem you don't need flow control, but I am not sure at all about how the serial interface behaves...

What I can tell is that you can wire an cross rts/cts signals in null modem and select rts/acts as flow control and it works if both equipment support that, for instance two PCs.

The fact that you receive something may give a clue. If you don't set the correct flow control line, you wouldn't receive anything.

Reading one byte, then garbage, then another byte sounds as wrong bit count or start/stop duration. Try using 7 data bits and one parity bit. Also extending stop to 1.5 should make no harm.

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