DEC RK07 drive interface specs wanted

From: Jochen Kunz <>
Date: Thu May 13 11:07:36 2004

On Thu, 13 May 2004 07:25:20 -0700 (PDT)
"Peter C. Wallace" <> wrote:

> > Give me hardware and I'll care about the NetBSD port.
> Thats a dangerous offer...
I have experience in porting NetBSD to new hardware platforms. If it is
an already supported CPU the work is not that hard.

> I may not be that expensive nowadays. A MIPS or ARM SOC with PCI for
> I/O expansion [...]
I would prefer some PowerPC based stuff. I don't know about the embedded
MIPS chips, but I know how fast a StrongARM or Xscale is and that a
(quite old) 300 MHz PPC604e is much faster. PowerPC is very well
supported in NetBSD and GCC[1]. It is continuously improved thanks to
the macppc users.

Maybe it is posible to use an already existing evaluation board and
interface it to the UniBus...

> CPUs without PCI are even cheaper.
I would not use non-PCI devices. If all I/O beside the UniBus hangs of
PCI, all you need is a machine dependent PCI backend in NetBSD to give
you acces to all PCI devices already supported by NetBSD. That way you
need only to implement a single driver for the PCI bus, not one for
every device on your board.

> Discrete mosfets with RC at the gates (say sot23 if surface mount)
> would give you all the drive you needed without excessive edge rates.
> The input side could be done with Schmitt trigger CMOS parts or even
> quad comparators if you wanted to get fancy about input threshold...
Well, when you say. Discrete analog stuff is not my territory. ;-)

[1] GCC likes to generate sub-optimal code for "non mainstream RISC"
CPUs and you have to be prepared for compiler bugs on "non mainstream
Received on Thu May 13 2004 - 11:07:36 BST

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