[Coco] 16/32 bit 6809 derivative

[Joel Rees]

2017/09/23 23:31 "Gene Heskett" <gheskett at shentel.net>:
>
> [...]
> > Yeah, if I had the money and time to design this thing, it would make
> > a good controller for lathes and such.
>
> No need to. the pi runs linuxcnc, straight from the x86 repo.  Slow video
> of course. The problem with the pi is dropped events, such as keyup etc
> from its own local keyboard. ALL i/o that is not from gpio=spi at 30+
> megabits, comes and goes via an internal usb2 hub, and usb2 silicon
> hasn't the traffic control to manage that properly when the data is
> async from human fingers.
>
> The rockchip propaganda says that data pinhole doesn't exist in its 44$
> card with 4GB of memory.

(Me muttering something useless about serial buses being another of
Intel's IP sinkholes.)

> I wrote some gui code that uses a $20, 100 ppr hand dial from mpja.com to
> replace the mechanical dials that no longer exist on the machine.
> Accuracy down to .0001" per click, but that data comes and goes thru the
> spi interface, and its never made any such mistakes. It Just Works(TM).
> Dial output is a-b in quadrature, no x, so commands are all relative but
> dead accurate.

Cool stuff.

> > But for the foreseeable future, the ARM in your rockchip is going to
> > get you
> > there a darn sight faster.
> >
> > (Darn. :-/ )
> >
> But, I may have to build the kernel due to the internal architecture of
> the rockchip, I still need rt-preempt to run linuxcnc, and I've serious
> doubts the kernel in the iso I've downloaded for it is configured for
> that. On the pi, a 1 millisecond servo-thread has a jitter of only 20
> microseconds when theres no video activity.  Thats excellent for a servo
> thread only machine, and is largely absorbed by the interface card which
> is pretty smart, its a 400k fpga.  Field reprogrammable of course.
>
> [...]

Looking forward to hearing how it works out.

--
Joel Rees