a printer oddity

Roy J. Tellason rtellason at verizon.net
Fri Apr 11 16:04:12 CDT 2008

On Friday 11 April 2008 16:14, Mr Ian Primus wrote:
> --- "Roy J. Tellason" <rtellason at verizon.net> wrote:
> > First is that right next to the usual parallel connection there's another
> > connector,  a DB25.  That bit seems to be a little loose,  and I'm
> > thinking plug-in board maybe?
> Yup. A lot of OkiData printers had their parallel ports on a plug in card,
> which in turn has a connector on it for a piggyback serial interface board.
> IIRC  it's held in with some plastic clips.

The one I know most intimately is my old 92,  which had such an arrangement.  
You'd plug that board in and flip one DIPswitch in there someplace.

> > The other thing is that attached to that connector is a little adapter, 
> > which has an RJ-45 socket on the back side of it.  The plug side of it has
> > only a small number of the 25 pins actually installed.  If I can figure
> > out a way to pop the shell open maybe I'll trace it out, otherwise I'll
> > probably take the ohmmeter approach.  :-)
> That's pretty common as well for serial interfaces.

Probably got common after I stopped working on this stuff a lot.  :-(

> Using these little RJ45 adapter dongles made serial cables much easier (and
> cheaper). Need null modem?  Change the dongle. In-wall wiring was easier,
> with RJ45's at the wall. There isn't much of a standard wiring for these,
> unfortunately.

It figures.  Somewhere buried in a box I have some other cables,  RJ45 on one 
end of a short (2-3 feet?) cable and a DB25 on the other,  I think it was.  I 
never traced those out either.

> They were sold as "kits" with no pins inserted, and a prewired RJ45
> connector. You inserted the pins into the DB25 and clipped the thing
> together. 

Some of those connector shells can be opened easier,  some are pretty much 
necessary to destroy to open it.  If I can get it open,  I also have the tool 
to remove those pins,  if necessary.  :-)

Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space,  a critter that can
be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet Masters"
Information is more dangerous than cannon to a society ruled by lies. --James 
M Dakin

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