Cadmus/Cambridge-Digital QBus MC68010

[Skip Egdorf]

I am posting this to comp.arch because it includes board-level architectural
questions.

I am posting this to comp.unix.wizards because it includes unix questions
probably answered only by those who have been around a few years.

I am posting this to comp.sys.m68k because it is about a M68010 based system.

I expect that most answers will be via email reply rather than news followup.
I will post a summary if response warrents it. If you must followup rather
than reply, please only followup to the appropriate group.

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I have come upon 4 of the old Cadmus M68010 QBus CPU boards and 8 of the
related 512K memory boards. I remember Cambridge Digital selling these
back in the early-middle 1980s and thinking they would be fine upgrades
to some old 11/23 V7 systems. For those who don't remember, this system was 
built by a CAD vendor called Cadmus as an upgrade to Q-Bus systems before
the Microvax came along. Cambridge Digital's adds for these used the
phrase "Microvax your PDP." The system used the 22-bit Q-bus, but was before
the time of the C-D interconect private memory bus. The boards used two
40-pin ribbon connectors along the backs of the boards to provide what
was called the "S Bus" for 0 wait state connection to custom duel-port
(S-Bus QBus) 512K memory boards. I recall that in the early 80s, these were
a minor competitor to the Sun-2.

The boards work so far as the boot prom complaining when no proper device
is present.

One set of software with them is from Cambridge Digital and is labeled
"MUNIX V1.05 c1985" on a 1/4" DC 300XL tape cartridge.
A second set that includes normal Unix docs (in a very nice binder set)
seems to be directly from Cadmus, seems to be Sys V.1 (maybe V.2) based,
and is called "Unison".

These were cheap enough that I can afford to play with them, and so
I intend to use these to build one or two hobby-home systems. I have QBus
backplanes, SCSI and SMD controllers and a couple of disks, DLV-11Js,
DZV-11s, and a CDC 1/2" tape on an Emulex TC02 (TS11 emulating). I will
probably need an MT emulating tape...

A few questions:

1. Does anyone have access to more detailed design information on the
   Cadmus CPU? What was its memory management like? What kernel-visible
   registers or I/O-page addresses were interpreted on the CPU board?
   Does anyone have documentation that I could have/buy/pay-for-copying?

2. Does anyone have specifications for the S-BUS private memory bus?
   Does anyone have design information for the memory boards?
   Does anyone know of attempts to make denser memory boards?
   The existing boards fit 512K on a quad board with 64k technology.
   Did anyone make a board with 256k chips? The S-Bus cables seem
   easy to make with 40-pin connectors, ribbon cable and a cable press.
   Any problems or gotcha's?

3. Does anyone know what 1/4" drive and Q-Bus controller were used with
   these? The documentation mentions a Cipher drive on an MT emulating
   controller. From some Cambridge Digital boxes over which I slobbered
   sever USENIXes ago, I seem to remember Emulex SC03s (I have one) and
   some other Emulex controller on the tape (But which one???).
   The tapes are not QIC-11 or QIC-24. They are too early, and they
   don't work (Why not try 'em. The Sun was just sitting there...).

4. As I may not be able to find a way to read the 1/4" tapes, does anyone
   out there have copies of a system for these boards that I could get?
   In particular, could I find some way to get them on 1/2" tape. A TS11
   bootable system would be best, but If need be I can build disks from
   an already-running PDP-11 Unix system.

   The systems have V7 binary and Cadmus Sys-V.{1,2???} binary licenses.
   The Sys-V binary licenses have restrictions that updates can only
   come from Cadmus, but Cadmus is no longer around. I can't believe that
   AT&T will quibble over something this antique. (OK guys, just kidding...
   Please don't take away my long distance service...).
   Does anyone have suggestions about what I might find? and where?

5. Any other ideas, war stories, suggestions?