Mystery Q-bus boards
ethan.dicks at gmail.com
Wed Nov 22 05:11:21 CST 2006
On 11/22/06, J Blaser <oldcpu at rogerwilco.org> wrote:
> I've collected a number of Q-bus boards for PDP-11s and/or VAXen that I'm
> trying to identify and locate documentation for...
I don't have any docs on the CompuServe board, but I can give you a
historical tidbit or two...
Originally, the 36-bit hosts were interconnected with a network of
16-bit machines that routed your session to the right host (GO TRAVEL,
Eventually, real DEC PDP-11s got too expensive to maintain. At some
point (mid-to-late 1980s?), CompuServe started making "node" hardware
themselves. I've seen an Intel 486-based Qbus board, but was unable
to obtain one. I _do_ have a later enclosure for the X.25 nodes -
it's 3 9-slot Qbus backplanes in one largish rack-mount box. 3 reset
buttons, 3 run buttons, etc.
I have to reverse-engineer the front-panel (it's designed for
CompuServe's 486s), but once I do that, I hope to be able to run 3
OSes simultaneously in one box (I'm thinking RT-11, 2BSD, and some
As for your board, I see the 8 sets of 1-9 pads, but they don't look
like DE-9 spots for me (the pins aren't numbered the same way, and
with "3" linked to "5", and "7" linked to "4", it doesn't have the
right feel, but perhaps it's a DLV11J pinout, not a PC-AT pinout).
Also, I don't see any RS-232 line drivers. I _do_ see a 68B09 CPU,
and 8 2K 6116 SRAMs. I'm guessing that the 68B40 might be a ROM since
I don't see any ROMs anywhere else, but perhaps it's soft-loaded from
the host. It does have a somewhat conventional DC005/DC004/DC010 Qbus
Try here... http://www.rdrop.com/~jimw/j-boards.shtml ... for a
picture of what looks to be a CompuServe Node serial card.
Anyone else have any observations?
More information about the cctech