UniBone: Linux-to-DEC-UNIBUS-bridge, year #1

[David Bridgham]

On 11/15/19 3:01 PM, W2HX via cctalk wrote:
> LOVE the ideas, loved it when I first heard of it. But I'm a QBUS guy! Put me on the list when (if) you ever make one for qbus. GREAT idea!
> Eugene


Along these lines, it's been a long time since we've updated the list
regarding the QSIC project.  Have been slowly working away on the
project here.  The QSIC is, at a high level, similar to the UniBone
except it's on the QBUS and it's based around an FPGA rather than a BBB.

Work that's gone on is that the Verilog code has been written to access
the DDR SDRAM we have so we can support larger RAM disks and eventually
the Able ENABLE.  Haven't tested it yet.

Also have made good progress on designing the prototype circuit board to
replace our wire-wrapped test board that's served us well so far.  Some
final checks and it'll soon be time to send off to China and learn about
having circuit boards assembled.  Speaking of that circuit board design,
I put in the option to add bus termination resistors but they require a
part that no-one seems to stock.  I had a request in to Mouser to get it
for me and they said they'd look into it but I haven't heard anything
back for a few weeks now.  This jogs my memory to chase them a little to
find out what's happened.

Anyway, the web page for the QSIC is here along with a KiCad rendering
of what the prototype board would look like and a slightly more accurate
diagram of what the internal modules are like (may still modify that
some more as I learned about the AXI interface and may use that for
getting to the bus and that'll change how the crossbar switch works).

http://pdp10.froghouse.org/qsic/html/overview.html

Dave