Hiya,

I hope this is not too offtopic but it ain't full 51 either.
Today I found the control board of an old telephone distribution system (connecting various phones etc, sorry for my bad English, german term is "Telefonanlage"). It had a sticker from may 1984 on and I'm just interested in the ICs used on this board. I had no camera with me so I can't offer you a picture.
I strongly assume Siemens (Nixdorf?) equipment.
The ICs look silver have a distinct logo with S and a smaller N or H in. They have the following numbers on:

S143 K8 in 40pins DIL
S145A3 K6 in 40pins DIL
S153A1 8032 (<-- maybe what the last says, less than 40pins though)
S152 K7
S141 K5
S146A3 K8

I assume some of those are EPROMs and atleast one might be a microcontroller of some kind.

Just for historical interest, I plan to do nothing about the board.

thanks for your help,
Matthias