Re: Interested in USB for TURBOchannel (slhci at tc)?

[Dave McGuire <mcguire%neurotica.com@localhost>]

  Short and sweet: Put me down for 3-5 of these, depending on the final
price.

  Fantastic work!

                -Dave

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

-- 
Dave McGuire, AK4HZ
New Kensington, PA