Port-pmax archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Interested in USB for TURBOchannel (slhci at tc)?



And I am definitely interested, as well.  I have a 5000/240 that would love
one of these.

- Alex

On 04/02/2016 02:24 PM, Felix Deichmann wrote:
> > tinkering with a Lattice CPLD break-out board and a Waveshape SL811HS
> > USB board showed success: I was able to interface the SL811HS and
> > TURBOchannel of my DEC 3000/400. Code for "slhci at tc" was easy, as the
> > slhci driver seems mature (and portable) already.
> > The CPLD features a TC interface up to 25 MHz, is capable of I/O
> > transactions and interrupts, and even contains a basic option ROM as
> > required by TC systems' firmware.
> > It is a horribly "flying" lab setup with single wires between all the
> > connectors at the moment (hardly stable of course, but sometimes :)),
> > but I plan to design a "real" TC option module with custom PCB and even
> > bulkhead for myself (and others if interested) which will solve all
> > stability problems I hope.
> >
> > Do not expect it to be fast, SL811HS is a USB 1.1 controller (12 Mbit/s)
> > and its 8-bit interface is sub-optimal (and errata-prone). I calculated
> > SL811HS peak data rate over an optimal (back-to-back) TURBOchannel to be
> > ~1.25 MB/s for 12.5 MHz TC systems, and ~2.08 MB/s for 25 MHz systems.
> > Actual devices on the bus will show slower results of course.
> >
> > Is anyone else interested in such a TC-USB option? I could kick-off a
> > hobbyist maker project of professionally made modules (you would get the
> > assembled thing with parts soldered to a PCB, CPLD programmed and
> > bulkhead mounted) then. Costs depend on amount ordered of course, but
> > even for prototype/smallest volume I see it far below USD $100. I will
> > not earn a single cent. Otherwise I will build manually for myself only.
> > So please excuse cross-posting to the three TC-capable platforms (pmax,
> > alpha, vax). It's a NetBSD special right now :)
> >
> > More info is and will be available here (doc, pics, code, ...):
> > http://www.flxd.de/tc-usb/
> >
> > And the alpha port seems to have really broken bus functions for widths
> > <= 4 (dense vs. sparse TC space etc.). I will also come up with a patch
> > for that soon.
> >
> > Comments and suggestions welcome!
> >
> > Regards,
> > Felix
>


Home | Main Index | Thread Index | Old Index