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From: KEN@JPL-VLSI.ARPA
Newsgroups: net.micro.apple
Subject: Re(n): //c modem problems
Message-ID: <13336@sri-arpa.UUCP>
Date: Sun, 9-Sep-84 22:01:00 EDT
Article-I.D.: sri-arpa.13336
Posted: Sun Sep  9 22:01:00 1984
Date-Received: Fri, 14-Sep-84 05:43:23 EDT
Lines: 27

From:  Ken Adelman <KEN@JPL-VLSI.ARPA>

	Rumor has it that Woz (or someone that he programmed) thought
that apple could save a few dollars per apple by using a timing signal
that already existed on the motherboard instead of a 1.84320 Mhz
signal that the 6551 requires.	Since I have yet to hook my modem to a
//c, I haven't experienced this 1165 baud problem myself.
	The same rumor said that if you returned your //c to your
dealer and complained about it, that he would solder a 1.84320 Mhz
crystal onto the board in a pad that apple left for such a purpose.
Attempts to get our local dealer to this resulted in responses like
"but I don't even have the service manual...".
	If you don't mind voiding the warranty, adding the crystal
would be quite easy.  I recall that the 6551 will support either a
crystal being directly connected to it or an external timing signal.
Sounds like cutting one wire and soldering two.  I would be willing to
look up the pin numbers on the 6551 which the crystal should be
connected across, in case it is not obvious upon opening the apple.
	I would be more interested in hearing from someone who has
managed to get apple to fix it.  I don't know if apple's modems will
work with it, but I suspect that if they send the characters over the
phone at the same rate that their modem won't talk to a Vadic (1205
baud) on the other end.

					-Ken Adelman
					 Caltech
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