Below adverts do sound as if the companies did actually develope their "own" RS232 solutions - although it's also possible that they only redistributed [[RS232|known RS232 interfaces]] from other developers.
If somebody can confirm that the hardware does really exist: Feel free to remove them from this "stub" page, and put the info on a separate page that describes the device. == Griesmayer Griesmayr ==
[[File:Griesmayer RS232 and Centronics Advert (CPC Schneider International, issue 12-1985, page 22).jpg]]
'''Griesmayer Griesmayr Electronic''' advertised "E.B.S. 464" (Expansion Board System) modules for 464/664: a '''IF1 parallel/serial data''' interface ([[RS232]], plus [[8bit Printer Ports|8bit Printer Port]]). As well as '''IF2 universal I/O''' interface, and '''SE1 5-slot motherboard''', and SK1/SK2 cables.
== Gundermann ==
Gundermann Mikroelectronik - advertised a '''dual highspeed rs232''', and (a separate product) a '''48-pin parallel I/O''' interface.
[[Category:Peripherals]]