Lovuschka: There is a lot to say about Ossi Weiner. First of all he is a big name in the German computer chess programming of the 1980s and 1990s. He was working together with Richard Lang on the Mephisto computers from Hegener & Glaser (source: Rochade Europa, April 1993, title page). According to Alwin Gruber, Weiner had a company "Hobby Computer Centrale GmbH" in Munich that in 1986 was the official publisher of Fidelity computers (source: http://www.schach-computer.info/wik...).
In 1996 he was (according to de-Wikipedia, but without any source, see https://de.wikipedia.org/w/index.ph...) with Manfred Hegener the founder of the company "Millennium 2000 GmbH Hegener & Weiner" that sold the Millennium 2000 chess computers.
According to Der Spiegel, Ossi Weiner is a former architect (source: Der Spiegel, 8 December 1980, issue 50/1980. Reprint on http://www.spiegel.de/spiegel/print...).
I remember Weiner had an ad in the Europa Rochade in either the late 1980s or early 1990s: "Genau wie bei Ernst Musch / gehts weiter hier husch husch, / denn besser als Ossi Weiner / bedient Sie schlie▀lich keiner." This means that he took over some publishing company from Ernst Musch. As far as I can see, Musch also was specialised in chess computers, selling them in Ehningen, and has most likely died (at least several sources say so but without giving hard evidence). The exact circumstances of that are unclear to me, but it seems Ernst Musch died many years ago, according to one source, so further research is needed. It might be (this is only my speculation, however) that Weiner bought the shop after Musch's death.