A german company that produced the Wiedmann BTX Modul for Schneider Joyce. Wiedmann is listed as provider for some Amstrad support/spares on Cliff Lawson's semi-official Amstrad page, http://web.ukonline.co.uk/cliff.lawson/.
The company does still exist in 2010, and they do even still have Schneider and Amstrad logos on their webpage: http://www.wiedmann.com - however, they seem to be focusing on older (pre-computer) hardware now, see screenshots below.
Screenshots from www.wiedmann.com
- www.wiedmann.com as of March 2010
Homepage, 3/2010
Sonderposten, 3/2010
Eventmanagment, 3/2010
