Re: new paradigm 6+3=9 bits: three S&D drives, 8 axes... , 3 bits spare

Hi Doug,
If you use the spare bits to logically switch two or more
octal buffer latch chips you will gain a second or even a third bank
of 4 motors. The latching buffers will hold the last logic levels so
the motors won't jump! You will still need drivers for the motors!
It can be done! The computer divides it's time between LPT1 and LPT2
so splitting the LPT1 by four is even possible. The technical term is
multiplexing. Now if you are talking about something else, check
with Dave Kowalski. He has a program that drives eight drives if I
remember correctly.

Bob

--- In CAD_CAM_EDM_DRO@y..., Doug Fortune <pentam@h...> wrote:
> cncdxf@a... wrote:
> >
> > Hi Doug,
> > It is obvious you would need new software.
>
> It is obvious that very slight changes to existing
> software are required.
>
> The disadvantages are:
> - Very slight modifications of existing software.
> - Considerations of these changes when writing Gcode
> - cost of one 'device' (and of course the wait for it
> to become a reality).
>
> The advantages are:
> - you only need to buy 2 or 3 drivers
> - you have access to 8 axes (or 16 using 4 bits, or
> 32 axes using 5 bits, or 64 axes using 6 bits)
> - for heavily used axes, you can multiplex them between
> the drivers to decrease the stress on any individual driver.
>
> > Then why not just add a second LPT port
> You lose the advantages of the new method. If merely adding
> a second LPT port satisfied my constraints, I wouldn't have
> proposed a new, different design!
>
> If your drivers cost only a few dollars each, no big deal.
> However, we are currently discussing the case where the naive
> increase in the number of drivers is undesirable (due to the
> existing constraints).
>
> BTW, I am in the market for such a device, if any of the
> electronics experts wants to brainstorm with me offline.
>
> Doug Fortune
> http://www.cncKITS.com