Retro Challenge - 2014 WW - Day 15

VOIP Setup (Again)

Reconfigured my other firewall that has VOIP built in to sit on one of my Internet facing IPs.

I have configured 4 VOIP lines each with a local rate number (not like the 1980s where it would cost you 10p a minute).
The lines are using the G711A codec which is uncompressed, this uses more bandwidth but should be able to cope with the limited frequencies used by the V23 modem.

So to dial into the system you can contact it on...

(0845) 0950081

Just set your modem to V23 (1200 / 75, 7E1) and use a suitable ViewData / VideoTex terminal.

I will be setting up the other lines next week.

Prism VTX 5000

I managed to get hold of one of these units on ebay the other day, this was the piece of kit that I remember using at a friends house when I first used Prestel.

Below you can see the manual toggle switch for putting the unit online. There are also Rx and Tx modes that let you connect to other modems instead of Micronet.

Tried dialing the server, its very fussy about the line. Managed to get it to connect once but I think it needs to be connected directly to the wall rather than through a long extension lead.

Retro Challenge - 2014 WW - Day 8

Multiple Modem Support

Added multiple modem support into the dial up server. Set the modem initialization strings in the configuration file along with the com ports for each modem required.

Plugged in the Hayes and the USB modem below and configured them in the new settings file.

USB Modem

Tried to get the USB modem to work, it responds as expected but there is something wrong with the data being sent to the terminal. It looks like its not using 7 even one, not sure why this is the case.

You can see it is sending the screen as certain characters are displayed correctly, it seems to be messing up the rest.

Have played around with several of the modem settings and can't seem to get this to work correctly, the Hayes modem works perfectly with the same settings.

After some more investigation it seems that the USB modem is using the wrong parity setting, it appears to be using odd parity even when I've asked for even.

Retro Challenge - 2014 WW - Day 7

Dial Up Server

Created a dial up server that connects to the back end ViewData service. The server can be run as a windows service or a console app.

Got the server to connect to the back end when the modem goes online, key presses were going from the terminal to the back end correctly but everything on the terminal screen was garbage.
Checked the back end was sending data to the dial up server and the characters expected seemed to be being sent to the terminal.

All I was getting was this...

Searched through the code and found the problem, after checking the serial settings over I noticed that the parity was set to None and it needed to be Even.

Changed the settings and got a connection from the back end.

Once this was working fixed a few things and tweaked the server to ensure that it disconnects from the back end correctly on modem disconnection.

Now that the server was working I've added some back end infrastructure to help me build pages etc. To start with the system now displays a nice "CONNECTED" message once it connects to the back end. Once you have finished on the system and exit from the menus the system will display "CONNECTION TERMINATED" and disconnect the modem.

So to demonstrate the system working I built a quick screen which loads from the server, the next step is to add a menu system.

I decided that the system should have a nice welcome screen which should pay homage to the original Prestel system...

To show the entire system working I knocked together a quick video if the system being dialed by the terminal...

Retro Challenge - 2014 WW - Day 6

Initial Testing Setup

Well managed to get everything talking, the setup is as follows...


Setup to allow me to dial between the machines, the PBX has 8 ports and 3 external lines. Eventually the idea is to connect the incoming modems to it and allow incoming connections via dialup.

Hayes Acura Modem

This is currently the modem I'm using for development as its a great modem and is pretty solid. Its one of 4 that I have which are brand new and still in their boxes.

This is connected to my development PC using a serial to USB adapter, eventually I either want to use the USB modems or have the 4 Acura modems connected to a serial card.

Terminatel 257

This is a black and white VideoTex terminal from Alcatel. It was a new boxed item that hasn't been used and would have probably been the sort of terminal used in France up until the demise of Minitel in 2012.

BT 746 Rotary Telephone

I acquired this the other day to complete my 80s retro desk setup. It is pulse dial only and does not work with the PBX but I have a new DTMF upgrade to fit to it before the end of the challenge. There's is something quite satisfying about dialing the modem with it.

Initial Test

Used Putty to create a terminal connection to the modem, manually setup the modem using AT commands and set it to auto answer.

Dialled into the modem from the Terminal and they connected ok.

Once in could type on both Terminal and Putty and they were exchanging data correctly.

Retro Challenge - 2013 SC - Day 7

Finally got some time to actually do something for my RC.

Tried to get my USB modem to work with my Windows 8 machine but the drivers are pretty much useless and it isn't detected automatically.
Finally decided to break out my old XP laptop, problem is that the keyboard doesn't work so found a USB one and got it up and running.

While I was at it found a replacement one on ebay so may get round to sorting it out before the end of the month.

Connected up the modem to the C-Tel analogue PABX that I bought a while ago for the purpose of providing old school dialing between machines and possibly the internet.

To test the PABX was working and everything should be ok before I start on the older machines I grabbed my old Acorn Pocket Book 2 and Psion 3 Fax Modem and wired them in.


Using the comms software on the Pocket Book and a copy of Putty on the PC I tried dialing the PC.

At this point the Psion modem started with the usual warbling but the PC wasn't happy at all.
I tried dialing the other way round, the USB modem was not having any of it.

I then remembered the laptop had a built in modem and after a few minutes finding the driver online all was good.

Found my Psion 8mb SSD with the internet suite installed and tried dialing the PC using the built in dial in settings, the PC responded but the error in the log indicates that the Psion didn't authenticate correctly.

So at least I have the two machines dialing each other, next step is to setup some kind of dialup server or BBS, have looked at Synchronet and may have a play with that before trying one of the other machines.