Re: Kulago/Mauch DRO ISA quadrature feedback kit with new timer

[Doug Fortune <pentam-at-home.com>]

Jon Elson wrote:

> Doug Fortune wrote:
>
> > Why not just add that functionality onto the Kulago/Mauch quadrature
> > feedback (DRO) ISA board?   The raw pcb board is cheap enough at $20
> > (probably still be $20 after the new circuit traces are added) and if

                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

>
> > some people don't want the quadrature feedback features, they just
> > leave those related IC's off.   Later if they need it, they can add the IC's.
>
> I don't see how I would "add that functionality" to the existing Kulaga
> board layout.  Should I just glue an 84-pin FPGA upside down, and run
> wire wrap wires all over the place?  This doesn't really make much sense.

Yes, of course a new pcb would have to be generated with the appropriate
new traces (for the FPGA and helper IC's) as indicated above.

A few reasons why I made the suggestion:
- Kulago's design is public domain, so there shouldn't be political
    complications in extending its functionality (as per Kulago's intention).
- EMC drivers are already written.
- The  ISA interface details is a complication which has been solved
    and is working.
- It is well known that "incremental improvements" tend to happen,
   whilst "from scratch" projects take longer, if at all.  So building on
   points 2 and 3 above might improve chances for success and speed
   of completion.
- Both functions (quadrature input and hi-res timer) are severally
   and jointly desirable EMC improvements, and might as well go on
   the same card in order not to duplicate interface chips, and consume
   extra ISA slots (the number of which tend to be limited on modern
   PCI motherboards).  As pointed out, since the functions are separate,
   if one of the functions is not required, then those chips can be left off
   the board (saving a bit of money), and can always be added later if required.


Doug

PS:  You were right on the Renishaw 5 micrometer prices: not much
change left from $1000/axis.  Whilst US Digital prices are ok, their
maximum resolution is 360 steps/inch.  What I am searching for
is something intermediate in price and resolution (maybe 0.000 10"/step).
So everybody, keep your eyes peeled.....