Mystery board

Subject: Re: Mystery board From: joe heck <trash3 at splab.cas.neu.edu> Date: Sun, 08 May 2005 07:37:36 -0400 To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> Well, I cannot tell exactly what it is, but there are lots of clues: Not Qbus, it's a hex board. Well, I have actually seen some custom backplanes that are six wide and use qbus cards, but that is pretty rare. Very few external connectors that I can see. Probably not disk/tape. At least three types of memory, although I cannot read the numbers. It looks like a bank of 8 dynamic memory chips, then three static ram and finally an EPROM. I'll bet on the top edge is the Z80, but the I/O chip next to it (if that is what it is) would give some more clues. It would be good to see if the crystal is divided for various baud rates, and if the connector on top has 8 bits or is serial. the missing chip on the upper left might be serial i/o. best guess, some sort of intelligent slave serial communications I/O processor. But it's just a guess. Joe Heck Charles wrote: > I have an unknown hex-height board which was included in a > miscellaneous lot of PDP-8A boards I recently purchased. But there > is no manufacturer's info except what looks like "K-3VO" in the > lower left corner, where there is a strange looking clamp-on > connector. Nothing is engraved on the metal "handles". There is a > Mostek 3880 (Z80 CPU) at the upper right, too. Date codes on all > the chips are '82 - '83. > > Here is a link to a picture of it: > http://img2.imageweb.info/img2/6gj14927.jpg > > and a closeup: > http://img2.imageweb.info/img2/aqw15714.jpg > > Anyone know what this board is? > > thanks > Charles >