Using a WiFi Modem with Telstar

Created: 4th April 2021

If an WiFi/internet modem is being used to access Telstar such as the WiModem232 there are a few things to be aware of.

Videotex terminal software does not normally send a CR (0x0D) but uses the ASCII underscore character (0x5F) instead. The videotex character set is slightly different to ASCII and the code 0x5F represents a hash/pound (#) when using the videotext character set. This can make it difficult to configure a modem using this software unless the modem can be configured to accept 0x5F (#) as a CR.

Some WiFi modems can be configured to accept the 0x5F (#) character as a CR thereby allowing the modem to configured easily with videotex terminal software in the same way as normal terminal software. For example the WiModem232 has a special Telstar mode that can be enabled/disabled using the AT*WS command

Some videotex client software can send CR using a control codes. For example using Ctrl M with Commstar will send a CR. The Telstar Client uses Alt M for example, in the Antelope software, Ctrl+D can be used.

Videotext systems tend to transfer data using 7 bits with the eighth bit being used for parity (7E1), as a result some videotext terminal software does not have the ability to change this. This can make it difficult to configure a modem using this software unless the modem can be configured to ignore parity. The WiModem232, when set to TELSTAR mode using the AT*TS command (described above) will ignore parity to allow AT commands to be used successfully. For details please see the documentation for your particular modem.

`Telstar Status`

Line 1: (01756 664433)
Status: OK

Line 2: (01756 664434)
Status: OK

TCP 1: (glasstty.com:6502)
Status: OK

TCP 2: (glasstty.com:6503)
Status: OK

`What's in a Name`

Telstar is named after a BBS with the same name that operated during the 1980s. That early BBS was created the author and a friend called Terry Slater. Telstar is an anagram of T Slater.

Prestel Servers were typically named after authors that originated from the area the server was located. The Telstar server names, Currer, Ellis and Acton are of course the pseudonyms used by the Bronte sisters, who like the author of Telstar, originated from Yorkshire. These have been selected as the names of the three Telstar servers.

`GlassTTY`

In the 1970s, character mode terminals e.g., ADM3A, VT100 etc. were considered preferable to the large cumbersome teleprinters. These new all electronic devices with their glass screens were often referred to as "Glass TTYs".