Unibus disk controller with modern storage - test-drb@ccmp.vtda.org

20 Oct 2016

...
  From: Paul Koning 
...
  That's fine if your target is an OS for which you
can write drivers. It
 wouldn't help RSTS users. 
Right, they're stuck with exact clones of DEC controllers. (For Unix, tweaking
the RP11 driver to handle the extended RP11 should take all of 12 minutes,
tops! :-)

...
  Q22 disks .. RL02 also, if I remember right. 
Oh, right, the RLV12 - forgot about that. Still, it would be nice to be able
to run RK11's and RP11's in 22-bit mode! :-) Especially since there will be
replicas of DEC's indicator panels for them, whereas an RL11 indicator panel
would definitely be... an anachronism! ;-)

...
  A possible answer for a lot of this is to do the
actual emulation
 algorithms in software, in an embedded CPU inside the FPGA. For MSCP
 that's obvious, but it would work for the others as well I suspect. 
Dave B is a wizard with Verilog, so until it gets to the complexity level of
MSCP we'd probably do it all in Verilog.

...
  From: Jon Elson 
...
  I did **ONE** board with some kind of gold flash that
a PCB house 
 recommended. ... it was a colossal disaster. You had to lift the pin
 ... Since then, I have used pure tin HASL, and had little trouble. 
I think gold came into the discussion in the context of the contact fingers
where the board plugs into the backplane. I've never seen a QBUS/UNIBUS board
with tin fingers, although they were common on SIMM memory cards; no idea
if tin would work for QBUS/UNIBUS - although now that I think about it,
SIMM cards didn't slide into position, but kind of rotated, so maybe tin
would work there.

	Noel