Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uwm.edu!ogicse!blake!milton!whit
From: whit@milton.acs.washington.edu (John Whitmore)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Hackintosh Monitor problems
Keywords: Monitor, Hackintosh
Message-ID: <2058@milton.acs.washington.edu>
Date: 21 Feb 90 07:42:24 GMT
References: <20509@netnews.upenn.edu> <686@chem.ucsd.EDU> <7658@mentor.cc.purdue.edu>
Reply-To: whit@milton.acs.washington.edu (John Whitmore)
Organization: University of Washington, Seattle
Lines: 28

In article <7658@mentor.cc.purdue.edu> leburg@mentor.cc.purdue.edu (Brian Pierson) writes:
>	I have a Hackintosh SE and a Samsung MZ4571. It is close to being done
>except I have two big problems.
>
>		1. I can't get the screen to center itself. I have tried to
>			increase the delay by putting in the fourth cap and
>			by putting in more resistance as per Les Hall's
>			Computer Shopper article.
>
>		2. The screen rolls vertically
>
	The screen centering should be mainly adjusted with the controls
in the monitor (possibly labelled horizontal phase, or phase, on the
circuit board).  If this range is inadequate, make a LARGE change by using
the inverted HSYNC signal, i.e. add one section of an inverter to the
HSYNC signal, then try again with the monitor adjustment.
	The VSYNC signal from the SE is not similar to that on the
MacPlus; you may have to lengthen the signal by some means: a 
monostable (one-shot, 555 timer) or a Schmitt trigger and some 
diodes/resistors/capacitors.  The VSYNC pulse from the SE board is
very short, compared to that from the MacPlus, and may not be
correct for the Hackintosh circuit and your monitor.  Try to 
ensure that VSYNC stays low for about 2 ms.
	I built my FrankenTosh a few years before the articles
came out, and felt my way through my entire video conversion
with an oscilloscope and no schematics.  It wasn't TOO bad.

I am known for my brilliance,              John Whitmore
 by those who do not know me well.