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From: dlb5404@tamuts.tamu.edu (Daryl Biberdorf)
Newsgroups: comp.sys.3b1
Subject: Re: Need 3b1-end pinouts for parallel interface
Keywords: parallel pinout
Message-ID: <12356@helios.TAMU.EDU>
Date: 19 Feb 91 18:39:09 GMT
References: <12347@helios.TAMU.EDU> <11489@jpl-devvax.JPL.NASA.GOV>
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Organization: Texas A&M University
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In article <11489@jpl-devvax.JPL.NASA.GOV> mark@jpl-devvax.JPL.NASA.GOV (Mark R. Rubin 4-7794) writes:
>
>	:: I have been using a C. Itoh 8510 with my PC7300 for over five
>	   years. No problems. I use a standard, 36-pin, Amphenol,
>	   male-both-ends, Centronics-style, cable

The problem is that I don't want to buy a ready-made cable.  They're kind
of pricey around here, and I don't want to have to drive to Houston
or Dallas to pick one up at an acceptable price.  But before I make
my own, I'd like to know exactly how many pins *need* to be hooked up
and whether or not they're straight through (pin 1 on computer goes to
pin 1 on printer, pin2 to pin 2, etc.).

>	:: Vis. "... more common DB-25...": Everyone used 36 Amphenol
>	   connectors for parallel, and DB-25's for serial, before IBM,
>	   in their infinite wisdom, decided to use DB-25's for both in
>	   the their PorkChop (PC) series of machines. How many 5 volt
>	   parallel printers have been burned out by the +/- 12V of
>	   RS232 since then?

I wasn't attempting to make a judgment about the merits of using DB-25
for a parallel connector.  However, the PC "standard" is now 10 years
old and has an installed base of somewhere around 80 million.  Fat chance
you're gonna stop that juggernaut on the basis of whether or not
it adheres to the norm 10 years ago.

As for burning out printers, probably not many in recent years, anyway.
If I remember correctly, IBM boxes (actually made by IBM) use different
genders for the serial and parallel ports.  I usually try not to just
jab a connector into a socket without looking at its label, anyway.
Those who do are asking for disaster.  

Anyway, this is in no way intended to be a flame.  I'll still appreciate
any help anyone can give as far as whether or not I can wire a cable
straight through and exactly which connections need to be made (fewer
conductors means less cost for my cable).

--Daryl Biberdorf,  dlb5404@{rigel,tamuts}.tamu.edu
  Texas A&M University