OT: <was springfield> <is data transfer via parallel port off old systems>

[Don Y]

Roy J. Tellason wrote:
> On Wednesday 02 August 2006 05:02 pm, Don Y wrote:
>> I have an *8* headed "laplink" (lowercase L) cable but, IIRC,
>> they are just various combinations of connectors/genders and
>> pinouts (but still a serial cable).
> 
> That's a bit much.
> 
> I have a couple of 9-to-25 pin size adapters that I need to check the 
> connections on,  and am not sure I have them in both genders.  And some 
> connector shells that'll take a 25-pin connector at each end,  which I got 
> seeing them as being handy to make adapters with.  But the need for such 
> stuff never arrived,  so I never got around to building them,  except for a 
> couple of gender changers.  If I ever do it'll be easy enough to have one 
> test cable that's wired straight through and then make up any adapters I 
> might need.

I have a box of 25 pin M-F DB25 cables wired 1<->1.

And, a small box of "widgets" -- little 2x2" clamshells
with a pair of DB25's on each end.  Sex varies -- some are
M-M, some F-F, some M-F.

I wire each of these widgets for a specific purpose:
- gender changers (M->F, F->M)
- "null modem", "null terminal"  :-/
- PLIP
- Sun "port A/port B" swap
- device specific requirements (some devices use unusual
   pins for handshaking, etc.)
- etc.

This greatly cuts down on the typical "tangled box of
assorted cables" you find in most places.  And, the hassles
involved in trying to find THE right cable for the job.

Instead, I dynamically fabricate the cable that I need
by patching lengths of straight through M-F cables
together.  Then, apply whatever combination of "widgets"
are needed on each end (in theory, you only need to do
this on one end but sometimes you need a 25->9 pin
adapter and other times its easier to do some of the
"widgeting" on each end instead of having 2 or three
cascaded widgets hanging off one end of the cable)

The only downside is making the widgets -- since they are
so compact, getting 25 conductors in the clamshells is
a bit challenging (unless you resort to really fine wire).