Telstar Packet Assembler/Disassembler (PAD)

As part of The TELSTAR Videotex System PSTN (dial-up) access is supported using SIP telephone lines and the Asterisk Softmodem module. As a result, Telstar can be accessed on tel. 01756 664433.

In addition there is a Packet Assembler/Dissassembler (PAD) on 01756 664434. This allows access to other Viewdata systems and BBSs as well as Telstar. When connecting to the PAD you are greeted with a promt which allows simple commands to be entered to connect you to any internet system.

The user interface to the PAD was designed to be similar to PSS/PAD software in that, once connected to it using a modem, the PAD software can be used to connect to remote internet based services using TCP/IP. When connecting to TELSTAR directly on 01756 664433.

By connecting to the PAD software using the telephone number 01756 664434, the PAD prompt is presented, thereby allowing services other than TELSTAR to be accessed e.g.

   PAD>


At the current time the system is experimental and is restricted to only a few services and commands. The list of services can be displayed by using the HOSTS command, for example:

   PAD> HOSTS
   
   Name: TELSTAR
   Name: NXTEL
   Name: CCL4
   Name: TEEFAX
   Name: EOTLBB
   ...
   
   PAD>

Any of the systems can be called and from this point the connection is made over the internet. Naturally, you will need to configure your terminal appropriately for the service you wish to access e.g. viewdata, ANSI, VT100 etc. The PAD will auto sense the data length and parity setting between the terminal and the PAD (e.g. 7E1, 8N1 etc). Communications between the PAD and the host will always use 8 bits for the data.

Connecting to a remote system can be done using the CALL command e.g.

   PAD> CALL EOTLBB

Assuming the connection is successful, all characters entered and received will be to and from the remote system.

When at the PAD prompt, a list of available commands can be shown using the HELP command e.g.

   PAD> HELP
   
   Commands:
   
     HOSTS        Returns the local directory of available hosts.
     CALL <node>  Connects to the specified host.
     HELP         Shows this file.
   
   <Ctrl> P will disconnect the host and return to the PAD.
   
   PAD>

Minitel terminals issue a series of control characters when they first connect which allows systems to detect their presence. The PAD will buffer these characters and present them to a remote system if a connection is made.