I'm pretty sure it is a Bernette 234 an early serger from Bernina, as it looks just like the one I have been using for abot 20 years. It still serges like a charm, and with the optional foot, does a nice rolled hem. The only problem I have ever had it that they are very hard to thread and you have to get it threaded exactly. The instruction book is not that great but if there is a Bernina dealer near you maybe they would help you out(--but probably would want to sell you a new fancy one!).
If you have no use for it there are lots of charity sewing groups that would probably be happy to have it.