Path: utzoo!utgpu!cunews!bnrgate!bigsur!bnr-rsc!mascot@bnr.ca
From: mascot@bnr.ca (Scott Mason)
Newsgroups: comp.sys.amiga.hardware
Subject: Re: Tape Drives, Parnet & CIA's
Summary: Select a low capacitance cable to LAN the two Amigas
Keywords: Parnet, CIA, Amiga, LAN, cable, capacitance
Message-ID: <4290@bnr-rsc.UUCP>
Date: 5 Apr 91 18:31:10 GMT
References: <16081.27f751e7@levels.sait.edu.au> <1991Apr3.193247.13318@jato.jpl.nasa.gov>
Sender: news@bnr-rsc.UUCP
Organization: Bell-Northern Research, Ottawa, Ontario, Canada
Lines: 41

In article <1991Apr3.193247.13318@jato.jpl.nasa.gov> jdickson@jato.Jpl.Nasa.Gov (Jeff Dickson) writes:
>In article <16081.27f751e7@levels.sait.edu.au> etac@levels.sait.edu.au writes:
>>
>>        My flat mate also has an A1000 and we're trying to run
>>Parnet to network the two machine.  We've made two cables
>>one about 10 inches the other about 15 metres. The short one
>>works fine but the long one just won't go. I've checked the
>>cable a thousand times. I can't see whats wrong.
>
>	10 inches VS 15 metres (approx 1 yard X 15 = 45 feet). Try attenuation.
>

I would recommend a visit to your local electronics supply or hi-end audio
store. Select the cable with the lowest capacitance per metre (that you can
afford). Each time the output switches, the driver must charge the cable
to the new logic state. The capacitance of the cable will have a direct
affect on this switching time. If you have routed near other electrical
appliances, such as power supplies or monitors, the cable may be picking
up considerable noise. A shielded cable will help eliminate these types
of problems. The shield should be grounded at one end *only*, and left
unconnected at the other end. This prevents currents from flowing in the
shield. If you can control the data rate, a lower data rate should be able
to communicate over a longer distance.

>>        Is this all due to just the poor drive of the 8520 CIA
>>chips or what?
>

15 metres is asking a lot. 

>>
>>Andrew Chalmers.
>>
>>Digital Communication Group D.C.G.

You're kidding, right :)

>>University of South Australia


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