Re: multiple parallel ports through one connector?

Carlos,

Maybe if Art V gets enough "fan mail" he'll consider changing this
IMO underutilisation of the p-port(s). I won't hold my breath<G>, as
many years ago when indexer was a new product, I asked him why he
chose to use the poert so "sparingly".

His reply was, "symmetry". And hundreds of people since have wrestled
with the same dilemma you face now... Product designers, take note?

First let me say that it really doesn't "look" too bad to use the
three cables. They come out of the pc next to each other, and if you
have them similarly arranged on your control box, it can actually
look kinda industrial "cool". But I useta play with patch cord
synthesizers, so I may be biased :-) It's certainly easier to
replace a standard cable if the need should arise.

Since the p-port db25's are already on the outside of the pc
enclosure, a "cable-based" solution is best, IMO. (this assumes you
don't have access to the individaul p-port pins INSIDE the case. If
you do, an answer lies further below).

An afternoon of work should allow you to make a 3 into one junction
box. Buy a small project box, and three identical printer cables (or
25 wire serial cables), along with your 50P scsi connector. Chop off
the "WRONG" end of the cables put them FAR AWAY (yep, I did.<g>)

Now with a multitester, sort out the wires you need. Since the cables
are identical, you "should" only have to do this with ONE cable as
the ones I've used were color codes under the outside jacket.(a
little "statistical" checking of the others is not a bad idea, IMO)

Make some holes in the box for the three cables and the 50 pin
connector, and solder away. Done.

Now individual p-port cards usually have the 25p connector integral,
but some "game cards, and multiple p-port cards will have dual inline
connectors for ribbon cable. If this is the case you're in luck.

Now all you need is some IDC (Insulation Displacement Connection)
style connectors for some ribbon cable (3 dual inlines, and a 50p
scsi), and the ribbon cable itself. You'll also need the metal
bracket that fits the 50p connector and fits in one of the computer
case rear "slot holes". One to 1-1/2 feet long should be about right.

Using an already assembled scsi ribbon cable would cut down the work
considerable, as you would only need to cut off one end, and affix
the three "board end" connectors...

From here it's simply a matter of getting the connectors properly
seated on hte connectors. There are special presses used commercially
for this, but many have used a bench vise. It is harder than it looks
to get a good connection this way; be SURE to check your work
THOROUGHLY. At the end of this you have a cable with 3 dual inline
connectors on one end, and a 50p scsi on the other.

Hope this helps.

Ballendo

--- In CAD_CAM_EDM_DRO@y..., "Carlos Guillermo" <carlos@v...> wrote:
> Hi All -
>
> Does anyone know if it is possible to take the PC's signals from
> three "parallel ports" and output them via one PCI card with a
> 50-pin SCSI or Centronics connector? Is such a thing available?
> I am trying to get IndexerLPT set up to talk to my controller box,
> and I'd like to find a cleaner way than using three separate
> parallel cables, and the associated breakout boards. Each port
> uses 14 pins plus ground. I know that 3 ports sounds excessive,
> but to drive 4 axes and use the joystick feature with the G-code
> frontend, I need 3 ports. The benefit is a lot of extra I/O.
>
> TIA,
>
> Carlos Guillermo
> VERVE Engineering & Design