Re: multiple parallel ports through one connector?

Hello,

There was an article showing a simple 8255 board set up for steppers
published by popular electronics or electronics now several years
back. Back issues are often available at college libraries.

The original article was for a plotter, I think.

And Chris is right, "talking" to an 8255 from within a program is
VERY easy. Maybe because that's an INTEL 8255 :-)

Hope this helps.

Ballendo

P.S. seems I also recall an Australian article and company (with a
website) selling 8255 boards rather inexpensively. and an american
company with a web name like wirz (read wires)...

--- In CAD_CAM_EDM_DRO@y..., ccs@m... wrote:
<snip>
>
> There is an alternative to multiple parallel ports, and that is a
> digital I/O board. These typically put something like 24 signals
> (maybe more) into a single cable. Talking to them is easy, but
> slightly different from talking to a parallel port, so it would have
> to be specifically supported by the software. Therefore you should
> probably contact ability systems with your question to see if they
> provide (or would be willing to add) support for something like the
> 8255 digital I/O chip used on many boards. If you are not strongly
> attached to indexer, any of the open source motion control packages
> could easily be made to talk to such a board (provided that it is
ISA
> and not PCI).
>
> One source of digital I/O boards is www.jdr.com
>
> You can of course bundle the cables from three parallel ports
> together, too.
>
> Chris Stratton
>