Newsgroups: comp.sys.next.hardware
Path: terra.net!news.sprintlink.net!howland.reston.ans.net!EU.net!Germany.EU.net!vampir.hnv.icem.de!euler!js
From: js@euler.hnv.icem.de(Juergen Sell)
Subject: Re: long printer cord???
Organization: Ink Unknown
Date: Wed, 21 Sep 1994 09:25:41 GMT

Here you go :

Newsgroups: comp.sys.next.sysadmin
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edu!netcom.com!netcomsv!angst!dylan
From: dylan@Angst.COM (Dylan Kohler)
Subject: Re: Longest NeXT Laser Printer Cable (long)
Message-ID: <1993Oct2.020713.5055@Angst.COM>
Sender: dylan@Angst.COM
Reply-To: dylan@Angst.COM
Organization: Angst Animation Post Production
References: <28homr$7sb@TAMUTS.TAMU.EDU>
Date: Sat, 2 Oct 1993 02:07:13 GMT
Lines: 168

In article <28homr$7sb@TAMUTS.TAMU.EDU> daugher@cs.tamu.edu(Walter C.  
Daugherity) writes:
> | In article <1993Sep29.032602.7487@hot.com>, Robert_La_Ferla@hot.com  
writes:
> | > Is it possible to get a longer NeXT laser printer cable?  
> 
> The standard NeXT printer cable is about 10 feet long.  There was a post 
> a year or two ago (which I didn't save) from someone who had 
> successfully extended one.
>
> As I recall he said NeXT used the signal propagation delay for timing so 
> a longer cable had to be just exactly the right length (75 feet???) so 
> that  signals would sync on the next clock pulse.
> 
> Maybe someone who saved the post can repost it, or maybe you can find it 
> in an archive.  Good luck!


I asked the same question and in one response got this bit of urban  
folklore.  If you succeed, let us know!





Begin forwarded message:

Date: Thu, 17 Sep 92 00:39:12 PDT
From: izumi@pinoko.berkeley.edu (Izumi Ohzawa)
To: tgr@trans.csuohio.edu
Subject: Re: longer printer cable
Cc: izumi@pinoko.berkeley.edu

In comp.sys.next.hardware article  
<1992Sep16.215632.26112@news.csuohio.edu> you wrote:
>We have 2 NeXTs here and one has a NeXT laser printer attached.  We have
>them configured so both computers can share the printer.   Here is the
>problem:
>
>The printer is in the directors office and we would like it outside of  
his
>office to eliminate any disturbances.  So I call NeXT support to get the
>specs on the cable so I can have a custom cable made.  They tell me it
>will not work and can not be longer than the supplied cable.
>
>So if anyone out there is using a longer cable on their NeXT printer,
>please drop a not to me to verify that it does work.
>
>Thanks,
>       Wayne
>

Yes,  I heard that you can use a longer cable but it has to be
really long like 80feet.
Officially, NeXT says you can't, but apparently it is possible.
You have to make your own cable.  Read on.

---
Izumi Ohzawa             [ Bg_78^=; ]
USMail: University of California, 360 Minor Hall, Berkeley, CA 94720
Telephone: (510) 642-6440     Fax:  (510) 642-3323
Internet: izumi@pinoko.berkeley.edu (NeXT Mail OK)

=============== Here's an old posting about this ===============
[Newsgroups: comp.sys.next.hardware
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lumbia.edu!src.honeywell.com!umn.edu!ux.acs.umn.edu!bru!newsman
From: brunkhorst@mayo.edu (Geoff Brunkhorst)
Subject: Re: Printer cable length....
Message-ID: <1992May15.150332.4258@bmw.mayo.edu>
Sender: newsman@bmw.mayo.edu (/home/bmw/usenet)
Reply-To: brunkhorst@mayo.edu
Organization: Mayo Foundation, Rochester MN. Campus
References: <78062@netnews.upenn.edu>
Date: Fri, 15 May 92 15:03:32 GMT
Lines: 76

In article <78062@netnews.upenn.edu> anstine@rm105serve.sas.upenn.edu  
(David
Anstine) writes:
> How long can the cable be? Can I use an amplifier to make it longer?
>
> -dave

It can be multiples of 80, plus 15 feet, if you use coax (see below)

this was a suggestion that is NOT SUPPORTED IN ANY WAY BY NEXT!!!
I received this from a NeXT SE, and am forwarding it to the net without
permission.  Sounded good.  If the original author sees this, he can
respond if he wants...

- Geoff

------------------------------------------------------------

You know how the official party line is that you can't make a longer NeXT
printer cable?

An engineer I knew at <name deleted> University didn't buy this story and  
has
successfully made an 80-foot long printer cable.
Here's some email he sent me about what was involved.

From: <name deleted>
To: name_deleted@NeXT.COM
Subject: Re:  lengthening a NeXT printer cable



I made a cable using seperate coaxs for each signal.  It
works fine, except that when the printer runs out of paper, putting in
more paper does not get the printer printing again.  <name deleted> found  
that
he had to turn the printer off using the soft window, and then it
starting printing again.

As far as signal skew goes, there should be no problem with data going
to the printer, since the CPU provides data and data clock.  However, the
return data may be suffering skew problems.  One solution, is to
adjust the length of the cable so the return data is skewed by exact
one clock cycle.  I will try this sometime and let you know how it
works.

<name deleted>

From: <name deleted>
To: <name deleted>@NeXT.COM
Subject: Re:  lengthening a NeXT printer cable

Hi again, Steve:

I measured the delay with the oscilloscope and found that that I made
the cable a poor length for skew.  I added enough cable to the return
data line so that the cable is now equal to 80 feet in length.  This
adjusted the skew for the return data one full clock cycle.  <name  
deleted> and
I tested to see if the running the printer out of paper still caused a
problem.  We found that the problem is fixed.

So, the moral to this story is to make long cables multiples of 80
feet (for 81% c coax).  The cable can be slightly longer that 80 feet but
not by more than 15 feet.  The cable can not be shorter that 80 feet.
These cable length should work:
    0 to  15 feet
   80 to  95
  160 to 175
  240 to 255
Of course the lengths will have to be adjusted for the velocity factor
if it is different than 81 percent.  Mabey, Next can make a special cable
and sell it!

<name deleted>

---------------------------------------------------------------
Geoffrey Brunkhorst, RCF                    brunkhorst@Mayo.edu
Guggenheim 10                                    (507) 284-1805
Mayo Foundation, Rochester MN, 55905 USA     fax (507) 284-5231  
[izumi@pinoko:+/NeXT-announce.nfold] %
================== end quote =====================



-- 
___________________________________
Dylan Kohler
Angst Animation Post Production
dylan@angst.com  (NeXTmail welcome)


Juergen
---
 Fon ++49-511-440688	NeXTMail welcome	Fax ++49-511-440617
 == What time do we live in when spontaneity and freedom get associated with instant coffee,
 == when a politician's idea of social change is changing names?
