DEC RK07 drive interface specs wanted

From: Peter C. Wallace <>
Date: Thu May 13 11:49:58 2004

On Thu, 13 May 2004, Jochen Kunz wrote:

> 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.

Then the Motorola 5200 might be about right... maybe overkill (400 or so MHz)
but its still pretty cheap

> 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
> CPUs".
> --
> tschüß,
> Jochen
> Homepage:

Peter Wallace
Mesa Electronics
Received on Thu May 13 2004 - 11:49:58 BST

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