The only I can say is:
It's Plessey 8-bit D/A, but I have no datasheet.
Look at http://www.elektronikladen.de/
Peter Keller

Agnes en Henk Tobbe schrieb:

> On an old - Elektor origin? - experimenting board, marked EMUF BASIC V2.1
> with the Basic 80C52 Basic processor I found two chips with the typenumber
> ZN428E-8. They may be A/D converters but I do not know. The manufacturer was
> Plessy. This organisation has been taken over so many times that their
> website does not hold anything ancient (chips are '91stamped).
>
> Does anyone know or has available:
>  what the chip does?
>  the diagram of the board?
>
> Help will be greatly appreciated!
>
> Regards
> VK2GWK - HENK
> Home page: http://www.users.bigpond.com/tobbe/index.htm