View Full Version : Obscure backplane system identification

November 27th, 2004, 07:35 PM
I am trying to get more information on what appears to be an obscure set of boards. There are at least seventeen, as indicated by the tabs on the board. They appears to have plugged into a backplane, and the boards have two sets of connectors, 100 pins and 56 pins with the 56 pins on top. The boards are labeled "Digital Services Corporation", and I'm assuming that this may have used something like CP/M because of chips like the 6809. I cannot tell what kind of interfaces this may have had as none of the boards I have seem to have any.

Unfortunatly I have been unable to gather very much from Google. I can describe these boards in more detail if someone has more knowledge of this than me.


November 27th, 2004, 07:40 PM
Pictures would certainly help.

Are there any other markings on the boards? What are the datecodes of the chips?

Are there any ROMs or PROMs and, if so, are they labeled in any way?


November 27th, 2004, 08:50 PM
These seem to me to be the two main boards.
The first has four chips of interest. First a Motorola chip, 6847 9/ ef68b09p in the upper left. Second a AMD chip labeled am9511a-1dc with a 1979 date on it. Third another Motorola chip labeled mc6850p. Last, a Hitachi chip labeled either hd46821p or hd6821p. There are also seven sockets for what should be proms, hand labeled. The adress range is from 0xb800 to 0xf800, but the chip for 0xc000 isn't there. I'm guessing the other number are part #'s. The board is labeled MPU/APU - 19d018 (can't tell if that's an 0 or O).
The other board has a pair of very large chips, 8705/ap 016kj1c, stamped TRW. This is labeled AC Board - 19d0051. There are actually a pair of these boards.
On another board (Encoder II) are three AMD am27s43pc 8725dg chips. On a fourth board labeled MPU Expansion - 19d0081 there are two more mc6850p chips, and a sony cxk5864pn-12l
I am unable to add images because I don't have a webserver handy to post them to. I will try to add some later.

Thanks again.