On Thu, May 13, 2004 at 11:31:25AM +0200, Fred N. van Kempen wrote:
Hmmm.
Replicating the RK611 in an FPGA is an interresting idea. - If you
can get complete shematics and there are no funky things like an AMD bit
slice CPU in it.
Nope, just logic.
The RK611, but not a UDA50 or anything
else that is "smart".
When I go through the work of designing a UniBus board, I would put
enough on it to run NetBSD on the controller. The UniBus attachment
should be implemented in a FPGA to have maximum flexibility in the
hardware. Software on top of this should be a NetBSD kernel driver,
perhaps with a userland daemon to support the kernel driver and control
it. It would be possible to emulate any UniBus device, including a
PDP-11, VAX, PDP-10, ... CPU. Unfortunately I don't have the experience
nor the resources to build a board like this.
"Hey, I can telnet / slogin to the disk controler of my PDP-11!"
That would be expensive, but you can do _anything_ with it. So you can
use the board for a wide range of applications, resulting in higher
production volume and lower cost. I know that a list member was
designing a board like this. I don't know how far he got. But my offer
is still valid: Give me hardware and I'll care about the NetBSD port.
The Unibus transceivers is indeed an issue- we dont
have heaps of
those laying around. On the other hand, their exact function and
specs are known (see the Peripherals handbook, 1972-ish or so),
and we should be able to re-implement them in discrete logic,
or bite the bullet and do a pin-compatible replacement, and
have 1,000 made.
A re-implementation in discrete logic was my thought too.
Depending how
it fits it may be possible to build a UniBus / QBus combi-board that
could be used in both busses depending on jumper settings.
--
tsch??,
Jochen
Homepage:
http://www.unixag-kl.fh-kl.de/~jkunz/