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Article #2950Re: Piggy back DIY upgrades -- don't change those resistors!
From: John Logajan
Date: Tue, 08 Aug 1989 04:57
Date: Tue, 08 Aug 1989 04:57
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> <8908070940.AA25858@ucbvax.Berkeley.EDU>, AWINFHAH@HMARL5.BITNET writes: > > The address lines have a 33 ohm series resistor between the MMU and the > > RAM array. Somebody noted that they are there to limit the current drawn > > from the MMU. This only partially true. Another (and probably the main) > > purpose of the resistors is to avoid ringing on the address lines. Oh, I fogot. Another reason to use such resistors is to cut down on system generated EMI (electro-magnetic interference.) All this electronic equipment has to meet FCC EMI standards -- and every little bit of attenuation helps. It stands to reason that if less current initially flows, and ringing is less, then less EMI will be radiated. -- - John M. Logajan @ Network Systems; 7600 Boone Ave; Brooklyn Park, MN 55428 - - logajan@ns.network.com / ...rutgers!umn-cs!ns!logajan / john@logajan.mn.org -
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!watmath!att!tut.cis.ohio-state.edu!uc!nic.MR.NET!ns!logajan From: logajan@ns.network.com (John Logajan) Newsgroups: comp.sys.atari.st Subject: Re: Piggy back DIY upgrades -- don't change those resistors! Message-ID: <1536@ns.network.com> Date: 8 Aug 89 04:57:14 GMT References: <8908070940.AA25858@ucbvax.Berkeley.EDU> <1535@ns.network.com> Sender: logajan@ns.network.com (John Logajan) Organization: Network Systems Corp. Mpls MN Lines: 16